As the calendar year closes and I look back on the year, three exciting new initiatives at Green Bank really catch my attention. LASSI, a new project funded through the NSF MSIP program, will place a terrestrial laser scanner on the GBT to provide near-real time surface corrections. By project completion in 2022, LASSI will allow for high frequency operations during the daytime, and increase the available high frequency hours on the GBT by 1,000. We are also well into the design phase of a new wideband receiver for the GBT. Funded by the Gordon and Betty Moore Foundation, the 0.6 – 2.8 GHz system will double the sensitivity of the GBT for most pulsar timing experiments and will provide wide spectral coverage for other scientific pursuits. Finally, the kick-off meeting for the new First2 STEM Student Success Alliance launched just last week. This alliance, funded by the NSF INCLUDES initiative and led by Green Bank, is comprised of many different organizations across the state of West Virginia and is focused on attracting and retaining rural, first generation students attending West Virginia colleges and universities.
The students and interns have gone home, the cafeteria staff all got to take last weekend off, and last night the temperature here dropped into the 40s (Fahrenheit). Green Bank’s summer is coming to an end. The summer itself was busy in a wonderful way – we had 10 summer students taking part in our REU, PING, and internship programs and an additional 36 other summer staff who worked on everything from painting the GBT to site maintenance and providing tours, food, and rooms to all the visitors on site. We were excited to welcome back the Governor’s STEM Institute to the site this year, as well as holding another PING camp for rising 9th graders, a digital signal processing workshop for high school teachers, Chautauqua Short Courses, Earth-Space science training for West Virginia teachers, StarQuest, SARA, Star Parties, and much more, all activities that kept the staff busy and gave many different groups of students, teachers, and the general public the opportunity to learn more about STEM, astronomy, and exciting new discoveries than they would through just a normal half day visit.
But with summer over we can now start looking forward to the fall and the increase in GBT observing time that comes with the end of summer maintenance and the increase in the number of beautiful, clear nights for high frequency observing. This fall we will be holding another observer training workshop as well as a workshop aimed toward people either planning on in the middle of large surveys on the GBT, looking for ways to optimize the science from these surveys. We are also in the planning stages for a couple of new instruments on the GBT which will increase the telescope’s scientific output at a variety of frequencies, and we will announce those plans as soon as they are fully in place.
Karen O’Neil
Director, Green Bank Observatory
Science News
Even Phenomenally Dense Neutron Stars Fall like a Feather
Harnessing the exquisite sensitivity of the National Science Foundation’s Green Bank Telescope (GBT), astronomers have given one of Einstein’s predictions on gravity its most stringent test yet. By precisely tracking the meanderings of three stars in a single system – two white dwarf stars and one ultra-dense neutron star – the researchers determined that even phenomenally compact neutron stars “fall” in the same manner as their less-dense counterparts, an aspect of nature called the “Strong Equivalence Principle.”
Einstein’s understanding of gravity, as outlined in his general theory of relativity, predicts that all objects fall at the same rate, regardless of their mass or composition. This theory has passed test after test here on Earth, but does it still hold true for some of the most massive and dense objects in the known universe, an aspect of nature known as the Strong Equivalence Principle? An international team of astronomers has given this lingering question its most stringent test ever. Their findings, published in the journal Nature, show that Einstein’s insights into gravity still hold sway, even in one of the most extreme scenarios the Universe can offer.
Observatories Team Up to Reveal Rare Double Asteroid
New observations by three of the world‘s largest radio telescopes have revealed that an asteroid discovered last year is actually two objects, each about 3,000 feet (900 meters) in size, orbiting each other.
Near-Earth asteroid 2017 YE5 was discovered with observations provided by the Morocco Oukaimeden Sky Survey on Dec. 21, 2017, but no details about the asteroid’s physical properties were known until the end of June. This is only the fourth “equal mass” binary near-Earth asteroid ever detected, consisting of two objects nearly identical in size, orbiting each other. The new observations provide the most detailed images ever obtained of this type of binary asteroid.
The Green Bank Observatory (GBO), Long Baseline Observatory (LBO), and National Radio Astronomy Observatory (NRAO), invite submission of brief Expressions of Interest (EoIs) in Principal Investigator-led “eXtra Large Proposals” (X-Proposals) for the Green Bank Telescope, Very Long Baseline Array, and Very Large Array (VLA) requiring 1000 hours or more of telescope time, and running over multiple semesters (and possibly multiple VLA configurations).
Responses will be used to gauge the level of community interest in such proposals, and their scientific potential. GBO, LBO and NRAO will seek advice from their advisory committees and the joint Time Allocation Committee on the EoIs submitted. It is important to note that the observatories may not proceed to a Call for X-Proposals if, for example, there is judged to be insufficient community interest, scientific merit, or differentiation from Large Proposals.
Expressions of Interest can be submitted using the web form at:
A total of 97 proposals requesting NSF funded “open skies” time were submitted to the Green Bank Observatory’s Robert C. Byrd Green Bank Telescope (GBT) for semester 18B. Proposals are reviewed on a competitive basis with a panel review system (see Proposal Review System). Below are the statistics by proposal count and hours. The oversubscription is the ratio of the number of submitted proposals to the number of approved proposals. The pressure is the ratio of the requested time to the available time in hours. Here we only include proposals submitted for the 18B semester that have been reviewed by the Green Bank Observatory Telescope Allocation Committee (TAC).
Optimizing Science from Green Bank Telescope Surveys
Since its commissioning, the Green Bank Telescope (GBT) has been used for a number of surveys that have produced unique data of lasting value. Recent GBT surveys are measuring star-forming molecular clouds in the Gould Belt, searching for new chemical species in Taurus, determining the HI properties of galaxies in the local Universe, determining the distribution of dense gas in galaxies and hot gas in galaxy clusters, searching for H2O megamasers in nuclear disks, and searching for new pulsars toward the north celestial pole.
The Green Bank Observatory (GBO) is interested in assisting its users who perform surveys. The assistance could take many forms: hosting a survey website; arranging team meetings; training student observers; organizing the observing; curating the final data products. To explore the ways that the GBO might assist survey science there will be a workshop “Optimizing Science from Green Bank Telescope Surveys” at the Green Bank Observatory on November 13-14, 2018. The goal of the workshop will be to develop practical policies for GBO support of survey science, but there will also be time set aside for survey team meetings, discussion with GBO staff on technical issues, or any other activity that might benefit current and future GBT surveys.
This workshop is intended for scientists and students who are involved with current or past GBT surveys, or who are planning future GBT surveys.
Logistics at the GBO limit the workshop to about 40 participants. There will be no registration fee, and all on-site expenses, include lodging and meals, will be covered by the GBO.
Green Bank Observatory recently bid a fond farewell to our 2018 class of undergraduate summer students. Eight students, three from the Research Experience for Undergraduate program, four from the Physicists Inspiring the Next Generation program, and one from GBO’s research assistant program, spent the summer living and working at the observatory. Their projects focused on pulsars and fast radio bursts, Galactic and Local Group HI, the conditions for water on Mars, new instrumentation for the GBT, and RFI mitigation. Our students were active members of the observatory community, participating in numerous education and outreach programs and local community events, in addition to their research projects. We look forward to seeing many of them at upcoming professional meetings – including the 2019 Winter AAS meeting, and as observers at the GBT – and wish them success in their future endeavors.
All undergraduate and graduate students are encouraged to apply for the 2019 GBO/NRAO summer student programs. We’ll have an informational table at the 2019 Winter AAS undergraduate student reception and throughout the AAS meeting in the main exhibit hall. Information about 2019 research opportunities will be available in December. The application deadline for the 2019 summer student programs will be Feb 1, 2019. Please visit our summer student program page for additional information on GBO and NRAO student programs.
Quick look display of a galactic center map from a 10 minute observation.
Twenty Meter Telescope Available for
Undergraduate Student Educational Use
The Green Bank Observatory is pleased to make the 20 Meter Telescope available for observational projects as part of college and university astronomy courses.
The 20 Meter Telescope was built in Green Bank by RSI, and funded by the US Naval Observatory (USNO) to be part of their Earth orientation observing program, and was operated by USNO from 1995-2000. In 2012, the 20 Meter was refurbished, and joined the Skynet Robotic Telescope Network project operated by the University of North Carolina, Chapel Hill.
The NRAO 20-meter telescope is the only radio telescope in the network, providing a unique capability to include radio astronomy as a lab component in university/college astronomy courses. Much of today’s professional astronomical research is multi-wavelength, with scientists using combinations of radio, optical, infrared, or other telescopes to gain a complete picture of the objects they study. The 20 Meter Telescope gives students the same ability and provides them with a better understanding of modern research.
Two receivers formerly used on the 140-foot telescope were revived and adapted for use on the 20 Meter, providing receivers sensitive to 1.3-1.8 GHz, and 8-10 GHz. The 1.3-1.8 GHz receiver is usually on the telescope providing access to studies of neutral hydrogen emission, OH emission as well as continuum observations to a declination limit of about -45 degrees.
Telescope time may be purchased for both educational and research activities. The highly competitive educational rate requires the observations to be used for student training and education as the primary activity. Professors and teachers interested in learning more about educational observing projects can contact Sue Ann Heatherly at sheather–at–nrao.edu. For detailed information regarding the 20 Meter capabilities visit [www.gb.nrao.edu/20m], or contact Frank Ghigo, 20 Meter Scientist, at fghigo–at–nrao.edu.
Spring is here in Green Bank, at least in theory (and if it would stop snowing that would be nice). This means we are now ramping up for our influx of summer staff and the many summer programs which we host on site. From workshops on single dish radio astronomy for undergraduate and graduate students, to REU and internship positions, summer camps for teachers and students, amateur astronomy gatherings, Pulsar Search Collaboratory meetings and training, and the annual Space Race Rumpus bike weekend, there is something for almost everyone going on here during the summer months. During this summer we are also spending time looking toward the future of the Observatory. As you will see in the ASTRO2020 article within this newsletter, we are actively soliciting input from the scientific community to help us shape our future and working with plan for what Green Bank Observatory should look like in 2020 and beyond.
Enjoy Your Spring!
Karen O’Neil
Director
News
Expression of Interest Invitation
Green Bank Observatory, LBO and NRAO invite submissions of brief Expressions of Interest (EoI) in PI-led “eXtra Large Proposals” (X-Proposals) for the GBT, VLBA and VLA requiring 1000 hours or more of telescope time, and running over multiple semesters (and possibly multiple VLA configurations).
X-Proposals are expected to be resourced by the proposing team. Projects should have extraordinary scientific merit and community legacy value, and will be expected to specify why the science goals cannot be achieved through the standard SRP/TAC process.
Responses will be used to gauge the level of community interest in such proposals, and their scientific potential. The observatories may not proceed to a Call for X-Proposals if, for example, there is judged to be insufficient community interest, scientific merit, or differentiation from Large Proposals.
The call for submission of EoIs is expected to be issued on June 1 with a deadline of July 11.
See the 2016 and 2017 NRAO User Committee reports for further background.
REU Students coming to Green Bank
Green Bank Observatory will be welcoming eight summer students in late May as part of the Research Experience for Undergraduates (REU) program and the Physicists Inspiring the Next Generation (PING) program. Students will be joining scientific and engineering staff for 10-12 week research projects and professional development activities. PING students will also spend one week mentoring middle school students participating in a science camp at the observatory. This core component of PING is designed to enhance the participation of underrepresented minorities in Science, Technology, Engineering, and Mathematics (STEM) fields. The Green Bank Observatory will also be welcoming a graduate intern working in the digital electronics group.
Astro2020 Update
The Green Bank Observatory kicked off plans for the Astro2020 Decadal Survey at the Winter AAS Meeting in Washington, DC. The effort started with the “Transformative Science for the Next Decade with the Green Bank Observatory” workshop in October 2017, which identified some key science drivers for the Observatory in the next decade. At the AAS meeting, Observatory science staff conducted an information-gathering session along with many of those very important booth and hallway conversations that spark new ideas. In January, we announced the Astro2020 activities for Green Bank with a letter from the Director to all who participated in the workshop and AAS activities to join the Observatory in crafting a series of science white papers in anticipation of a late 2018 call for papers. Science interests have been divided into seven scientific discussion categories and we are establishing teams for each category to identify key science cases and develop papers. The categories are:
Fundamental Physics (e.g. gravitational waves, general relativity, equivalence principle)
The transient sky (e.g. FRBs, SETI, Pulsars )
Stars & star formation (e.g. turbulence, magnetic fields, multi-scale molecular clouds, diffuse environments, ISM)
Galaxies & Galaxy Clusters (Milky Way and beyond) (e.g. cosmic web, HI extent of galaxies, galaxy structure, galaxy clusters)
Planetary systems (e.g. sun, stars, asteroid, comets, exoplanets, planetary weather/atmosphere)
Cosmology & Large Scale Structure
Response has been excellent with more than 60 scientists and astronomy professionals signing up for one or more discussion groups. We encourage anyone with interest in future science at Green Bank to join the Astro2020 team. More information about the Astro2020 program and information for interested participants is available at on our ASTRO2020 page.
We hope to hear from you. We will keep you posted on the progress of the teams in upcoming newsletter articles.
Pulsar Watchers Close In On Galaxy Merger History
Fifty years after pulsar discovery published, massive new data set moves closer to finding very-low-frequency gravitational waves, researchers say.
Gravitational waves are wrinkles in space-time that stretch and squeeze the distances between objects. In 2015, a hundred years after Albert Einstein realized that accelerating massive objects should produce them, these waves were finally detected from black holes with masses roughly 30 times the mass of our sun colliding with each other. However, Einstein’s theory also predicts another kind of wave, one that comes from the mergers of black holes with masses of hundred million times the sun’s.
Astronomers Solve Cosmic “Whodunit” with Interstellar Forensics
On the outskirts of our galaxy, a cosmic tug-of-war is unfolding. The players are two dwarf galaxies, the Large Magellanic Cloud and the Small Magellanic Cloud, both of which orbit our own Milky Way Galaxy. But as they go around the Milky Way, they are also orbiting each other. Each one tugs at the other, and one of them has pulled out a huge cloud of gas from its companion.
Solar System’s Largest Telescope Sees New Black Hole Details
Part of the global network of ground radio telescopes that participated in the observations. Credit: Paul Boven (boven@jive.eu). Satellite image: Blue Marble Next Generation, courtesy of NASA Visible Earth (visibleearth.nasa.gov)
Using the RadioAstron Space VLBI Telescope, an international consortium of astronomers have been able to observe ten times closer to a black hole and see new details of the jet formation region of Perseus A. These observations challenge some of the current models by showing jets much wider than predicted. The Perseus jets are in their infancy and astronomers plan to continue these ultra-high resolution observations to see how the jets ‘mature’ and compare observations of other active Galactic Nuclei to see how these results compare with other black hole jets.
All of this is possible because the combination of the RadioAstron spacecraft’s 10 meter telescope in orbit between the Moon and Earth, combined with multiple ground telescopes, like the GBT which contributed to the Perseus A observation, is able to resolve details beyond the capabilities of any ground-based telescope or array. Whenever the spacecraft is viewable in our hemisphere, the science data and spacecraft data are conveyed back to Russia by way of the 140’ Telescope acting as a data downlink, often as the GBT is simultaneously observing the same source as the spacecraft. Green Bank is pleased to provide the vital data connection that make observations like these possible.
Coming this Summer – New GBO Post Docs
Natalie Butterfield and Will Armentrout join the GBO Scientific staff in August as our newest Post Docs. Natalie has been an NRAO Reber Fellow attending the University of Iowa, and Will is currently finishing his PhD at West Virginia University with advisor, Loren Anderson. We look forward to their arrival this summer.
GBT Publications, 2018
A complete list of publications are available on this page.
EPO Happenings
Green Bank Observatory Chosen for National Leap Into Science Project
A diverse group of educators from the Green Bank Observatory, West Virginia University Extension Service, Pocahontas County Libraries and the Morgantown Public Library System have teamed up to become The West Virginia Leap into Science State Leadership Team. Out of more than 20 applications from around the nation, West Virginia was one of four state teams selected.
Governor’s School Returns to Green Bank Observatory, under a New Name
After a two-year hiatus, the Green Bank Observatory successfully competed to host the West Virginia Governor’s STEM Institute (GSI) for the next 3 years. GSI invites students to delve into projects that allow them the time and opportunity to think and work like scientists and engineers, using high level mathematics and thinking skills while employing the latest technology. The Green Bank Observatory program “Investigating the Universe”, is an intensive two-week residential program that engages 60 talented rising ninth graders from all over West Virginia in radio astronomy research. Our program is truly unique in that is embedded within the day-to-day workings of a national research center. Our students will have the opportunity to join our professional STEM community; working in teams with scientist-mentors, rubbing elbows with undergraduate students, and using some of the most sophisticated radio astronomy technology on earth.
Physics Inspiring the Next Generation (PING) Camp Accepting Applications
The Green Bank Observatory also hosts a similar camp for rising ninth graders with an interest in STEM from all over the nation. PING is free of charge, except for travel (we do offer shuttle service to and from Green Bank from DC, and Charlottesville VA). We encourage applications from youth who are traditionally under-represented in the STEM fields. Please help us spread the word.
Andrew Seymour officially joined the GBO Scientific Staff in January, 2018. He has been a visiting scientist in Green Bank since hurricane Maria stopped by the Arecibo Observatory for an unwelcomed visit. We talked to Andrew about his career, life in Puerto Rico and his journey to GBO.
Could you briefly explain your Scientific Career journey?
My career has been a bit of a “random walk”. After earning my undergraduate degrees in Mechanical and Aerospace Engineering, I decided to go to graduate school for Physics. There I did research with lasers and optics, then moved on to Chaos theory, but eventually did my thesis work on Astronomy and Pulsars. After graduate school, I moved to Puerto Rico to use the William E. Gordon Telescope at Arecibo, famous for being in the films Goldeneye and Contact, to continue my pulsar work. While there, one of the collaborations that I work with found a millisecond extra-galactic radio source known as a Fast Radio Burst. Follow ups on this source have produced numerous events at Arecibo in the past three years. Yet, this is the sole source to date to repeat, and it is still unknown what is causing these events. All of which has kept the collaboration and me pretty busy.
What was the most fun about working at Arecibo?
Since Arecibo is in the tropics, there was a lot of beach fun to be had. Yet I think I had the most fun with my co-workers. It takes a special personality willing to move to Puerto Rico, and we grew to rely on each other. Be it through a hurricane or the uncertainty of a NSF-EIS, we learned to laugh our way through it all.
Were you involved with any of the projects where Arecibo and the GBT work together? If so, could you talk about them?
There are many projects that use the unique capabilities of both the Arecibo and the Green Bank Telescope.The obvious ones are the Pulsar surveys and Pulsar timing projects. This is where measuring the radio burst from neutron stars can eventually detect gravitational waves from merging super massive black holes, like that found in the center of some galaxies. In order to achieve this, we need a large number of pulsars.
Therefore we want to search far and wide to find them. Arecibo was the largest radio telescope in the world, which allows it to search for very deep and weak pulsars. Yet because of its size, it cannot be tilted, limiting what part of the sky it can observe. Using the largest steerable structure, that is the GBT, is great for finding pulsars in the other part of the sky that Arecibo cannot reach. Arecibo searches the far, while GBT searches the wide.
What is the major difference between Puerto Rico and West Virginia?
The weather.
What are their similarities?
Puerto Rico and West Virginia have more in common than you first realize. Both have their unique dialects. The mountains can make it hard to get where you want to go. Not all the information you need can be found online. Be wary where the GPS sends you. Your cell phone might not work. In spite or maybe because of these “hardships”, both places have a tremendous amount of pride in the region they call home.
May 30 – June 1
2½ day workshop, geared toward college faculty who teach at small non-research colleges or community colleges, and who have an interest in learning about radio astronomy research.
For more info, contact the GBO Education Officer, Sue Ann Heatherly at sheather@nrao.edu
Space Race Rumpus
June 8 – 10
Space Race Rumpus is weekend-long cycling festival, based at the Observatory that raises funds for a Community Wellness Center.
June 4 – 8 For all summer students at NRAO and GBO sites.
ALFALFA-U Workshop
June 19 – 23 This workshop engages undergraduates and their faculty on radio astronomy projects with the ALFALFA Survey data. The workshop is part of an NSF-sponsored program to promote undergraduate research within the ALFALFA project.
ESS Passport Workshop
June 17 – 30 Professional Development workshop to prepare WV teachers to teach 9th grade Earth and Space Science.
We have just finished our first full calendar year as the Green Bank Observatory. It has been an incredibly busy year filled with many accomplishments, including the first high frequency seasons of the MUSTANG-2 and ARGUS high frequency instruments, and the commissioning of FLAG (and its associated beam-former), the most sensitive phased array feed system in the world. Full commissioning of the VEGAS spectral line observing modes is complete and initial pulsar observing modes have been released. We have enjoyed an unprecedented level of visitors to and media interest in the Observatory and the work we do. This year we also celebrated the 60th anniversary of the dedication of the Observatory, with a party looking back on the many accomplishments the site’s telescopes have had over the years.
In addition to all the activities described above, this past October we held a workshop which looked toward the future of the Observatory over the next 5, 10, and even 20 years. Workshop participants laid out a number of possible ideas for the site, and, as discussed in the “Preparations for the Decadal Survey” article in this newsletter, we are now asking members of the community to help us turn those ideas into a plan for the next decade or longer. We hope all of you with an interest in the long term future of the GBT and the Green Bank Observatory will help us shape the coming decades.
Dr. Karen O’Neil
Director, Green Bank Observatory
News
ASTRO2020 Preparations
We are preparing a long-term plan for the scientific program of the Green Bank Observatory and the GBT for the period 2020 – 2030. This review of current and future instruments will provide input to the 2020 Decadal survey. If you have an interest in science at the GBT or GBO please join us in this process. We envision that there will be a few small workshops at various locations during 2018 to develop the science cases and instrumental specifications. You can signal your interest by signing up on our web site.
Transformative Science for the Next Decade with the Green Bank Observatory – Workshop Results
From October 16 through 18, approximately 40 people gathered together to discuss possible scientific and instrumentation plans for the Green Bank Observatory in the 1-2 decades. The format of the meeting was designed to encourage significant discussion on topics ranging from star and galaxy formation and evolution through gravitational waves, pulsars, transients, astrochemistry, solar physics, the search for life, and solar system science. Each group of talks was followed by a discussion period on both the science and also how the Observatory can aid in accomplishing the science goals.
At the end of the workshop, we discussed the unique roles the Green Bank Observatory could have in accomplishing the varied science objectives, and laid out a number of possible paths for the future. Over the next year we plan to turn many of these ideas into grants, instrumentation plans, and one or more submissions into the upcoming Astro 2020 decadal survey.
The majority of the talks from the workshop, as well as the summary slides, are available online.
Anyone who is interested in continuing to provide input or in working with us on our long term Observatory plans and Astro2020 submissions should go online and register your interest.
A new look at IC342
IC342 is a face-on weakly barred spiral galaxy with a young nuclear star cluster surrounded by several giant molecular clouds. However, the connection between the bright nuclear bar and low surface-brightness or extended emission has not been well explored in the past. Using 12CO lines to trace molecular gas at both low and high densities, a new map depicts a high signal-to-noise image of the inner part of IC342 that includes the first spiral arm. These fully-sampled images of the distribution of dense gas in star formation regions and their precursor flows will show whether the amount of dense gas is sufficient to fuel the star-forming process.
Figure 01: High-resolution images of the ground-state carbon monoxide spectral line at 115.27GHz. These panels show the overall distribution of CO as integrated intensity maps.
This new look at the galaxy was obtained with Argus, a 16-pixel focal plane array on the Green Bank Telescope. This millimeter-wave radio camera is able to make large-scale images of astronomical objects in a fraction of the time, and with higher image quality, that a conventional single-pixel reciever takes. Graduate student Jialu Li, in collaboration with the Argus instrument team and DEGAS project, made these images (the highest frequency spectral line observations the Green Bank Telescope has ever made) in only 10 hours on 2017 October 25 and 26. The combination of the GBT’s 100-meter diameter and the short observing wavelength produces images with an unprecedented 4 arcsecond resolution for single-dish observations. This image, which is part of the DEGAS study of dense gas in nearby galaxies, shows the power of the GBT for observations of extended objects beyond our Galaxy.
Figure 02: The “Moment 1” panel shows the change of velocity across the galaxy, indicating a smooth rotation, while “Moment 2” gives the spectral line’s width, here showing a broad line toward the turbulent star-forming nuclear bar and more ordered motion in the arms themselves.
The Argus millimeter-wave camera on the GBT produces data cubes of the emission from spectral lines with high spectral and spatial resolution. Data cubes have two spatial dimensions and a third dimension of spectral information, providing images of astronomical objects that show both the distribution and motions of gas. Figures 01 and 02 summarize the information from IC342’s 12CO J = 1-0 spectral line data cube. Both IC342’s nuclear bar as well as its inner spiral arms are clearly visible.
The Argus+ Project at the GBT
The GBT is now into its second winter season with Argus, the 16-pixel camera for spectroscopy in the molecule-rich 3mm atmospheric window between 74 – 116 GHz. Argus is the brainchild of Sarah Church of Stanford University and collaborators, who received an NSF ATI grant to design a modular receiver system for the GBT that could be replicated and expanded in a straightforward way. With the unique combination of angular resolution (6.5 – 9 arcseconds), sensitivity, and field of view of the GBT, Argus is being used for ground-breaking surveys of dense gas in galaxies and nearby star-forming regions. Some recent Argus results will be highlighted at the upcoming winter meeting of the American Astronomical Society in Washington D.C.
The Green Bank Observatory and the original Argus team are now collaborating on the Argus+ project, which would take advantage of the technical development afforded by Argus to produce a camera with ten times the mapping speed. Argus+ will also include a new spectrometer and improvements to the GBT metrology that would double the time available for 3mm spectroscopy each year. Argus+ will routinely produce spectral line maps of key species such as CO, HCN, and HCO+ with a spatial dynamic range (map area / pixel size) of 104 to 105.
As part of the Argus+ project the community will be invited to participate in legacy surveys with the new instrument. There will be a spectroscopic survey of the Gould Belt molecular clouds, and a survey of dense gas tracers in nearby star-forming galaxies. The legacy surveys will produce unique data of lasting value. Argus+ data will also be displayed in exhibits at the GBO Science Center, and will be incorporated into a range of programs in STEM education throughout the region.
The plan for Argus+ has been submitted to the National Science Foundation’s call for pre-proposals to the Major Scientific Instrument Program (MSIP) with Felix J. Lockman (GBO) and Sarah Church (Stanford) as co-PIs. The project will leverage the NSF’s investment in the prototype Argus to produce a uniquely powerful scientific instrument accessible to the U.S. scientific community.
The 2018A call for proposals to use the GBT elicited requests for 4843 hours in 52 individual proposals. Twenty two proposals were approved for a total of 1748 hours.
The Time Allocation Committee Report for 18A can be found on the 2018A Proposal Call Results web page. A listing of the accepted 18A proposals can be found on the 2018A Science Program web page.
Summer Student Programs and Applications
The Green Bank Observatory summer student programs for undergraduate students runs from 10-12 weeks over the summer, from late May to mid-August. At the end of the summer, participants present their research results as a short talk and submit a written report. Financial support is available for students to present their summer research at a meeting of the American Astronomical Society, generally at the winter meeting following their appointment.
Besides their research, students take part in other activities, including a number of social events and excursions, as well as an extensive summer lecture series which covers aspects of radio astronomy and astronomical research. Students, may in their application materials, also indicate a willingness to participate in PING, an opportunity to mentor rising ninth grade students who will be onsite for 2 weeks.
The deadline for applications for 2018 is February 1, 2018. We will accept and review applications in conjunction with the NRAO summer student program again this year.
Green Bank Observatory Featured in Radio Astronomy Course
The Green Bank Observatory, and the GBT, feature prominently in a new course released by “The Teaching Company.” The course, part of their “Great Courses” series is authored by GBO astronomer, Jay Lockman, and is called “Radio Astronomy: Observing the Invisible Universe”. The “Great Courses” are not academic courses in the usual sense, but are intended to provide a college-level view of a subject for those outside the field, with no homework or tests. The company has over 200 courses on science and mathematics, and one of the newest is Jay’s 24-lecture set on radio astronomy.
Besides providing a general overview of radio astronomy, the new course spends two “lectures” on an actual tour of the Green Bank Observatory. The first covers some of the historic telescopes like the Reber, Tatel, and 140 Foot. The second lecture is devoted entirely the GBT and includes a tour from the track to the top of the receiver room.
The course goes on sale every few months and is available online.
Recent GBT Publications
Sample publications based on GBT data that appeared within the last few months. A complete list for 2017 is available on our Web site. If your paper should be in that list but is not, please let us know.
Long-term Variability of H2CO Masers in Star-forming Regions, Andreev, N., et al. 2017, ApJS, 232, 29
The Breakthrough Listen Search for Intelligent Life: 1.1-1.9 GHz Observations of 692 Nearby Stars, Enriquez, J.E. et al. 2017, ApJ, 849, 104
The High-frequency Radio Emission of the Galactic Center Magnetar SGR J1745–29 during a Transitional Period, Gelfand, J.D. et al. 2017, ApJ, 850, 53
A Radio Counterpart to a Neutron Star Merger, Hallinan, G. et al. 2017, Science, 10.1126 aap9855
2MTF – VI. Measuring the velocity power spectrum, Howlett, C. et al. 2017, MNRAS, 471, 3135L
The Green Bank Ammonia Survey: Observations of Hierarchical Dense Gas Structures in Cepheus-L1251, Keown, ,J. et al. 2017, ApJ, 850, 3
Diffuse Ionized Gas in the Milky Way Disk, Luisi, M. et al. 2017, ApJ, 849, 117
Probing the Outflowing Multiphase Gas ~1 kpc below the Galactic Center, Savage, B.D. et al 2017, ApJS, 232, 25
Temperature structure and kinematics of the IRDC G035.39-00.33, Sokolov, V. et al. 2017, A&A, 606A, 133
The Green Bank Ammonia Survey: Unveiling the Dynamics of the Barnard 59 star-forming Clump, Redaelli, E. et al., 2017, ApJ, 850, 202
Deep K-band observations of TMC-1 with the Green Bank Telescope: Detection of HC7O, non-detection of HC11N, and a search for new organic molecules, Cordiner, M.A. et al., 2017, ApJ, 850, 187
History
Scheduling Telescopes: Astronomers and Their Science
by Dr. David Hogg, printed with permission
It was my hope that by looking at how the NRAO developed its relationship with the users community I could better understand the way the Observatory evolved from its modest beginnings into the institution which has such a broad influence in global radio astronomy research. In the very beginning there was much controversy about the need for a national radio observatory and about how it should be operated. Eventually a process was developed under which a visiting scientist could submit a proposal to use one of the telescopes and obtain the data needed for his or her research. This process, developed in the early days at Green Bank, has endured throughout the history of the NRAO, albeit with modifications, some of them substantial.
The Principles of the Scheduling System
Once the 300-foot became available as a complement to the first 85-foot, the Tatel Telescope, it became necessary to formulate a policy which guided the selection and scheduling of observing proposals. A primitive first step had been taken in 1960 when the proposals were reviewed by Dave Heeschen, then the chair of the Astronomy Department. However, as the volume of proposals increased it became obvious that a more rigorous system was required.
Heeschen and AUI set out to develop a system which ensured that the proposals offering the best chance of producing important research would be awarded time on the NRAO telescopes. There was little guidance to be gained from the experience in optical astronomy, where the major instruments generally were managed by the sponsoring institutions, and the observing time was generally used by the staff of those institutions. AUI of course was managing the Brookhaven accelerators, and thus some of that experience informed the NRAO policy. In the end, the system was constructed on three principles:
Acceptance of an observing proposal would not be based on institutional affiliation. This concept is often known as “open skies”.
All proposals, whether from visitors or staff, would be considered together, and would be peer reviewed.
There would be no charge for telescope time.
Let me say a few words about each of these points.
The first principle, “open skies”, was not without controversy. It was intended to bring the best ideas to the telescope, but there was criticism that the policy was not reciprocated by many foreign observatories, so that US observers felt that they were being treated unfairly. In addition, there were occasional inquiries from Washington about what fraction of time went to non-US observers. The principle has been reviewed several times over the years, and undoubtedly will continue to be so.
The election to use peer review was made both to ensure that the NRAO staff was not treated more favorably, and of course to try to maximize the use of the telescope time.
There continues to be no charge for basic science although more recently both the GBT and the VLBA do undertake some directed programs for which funding is received.
No scheduling system is perfect. The early days of molecular astronomy presented a special challenge, because it was pretty wild and woolly. A new detection often earned a paper in the ApJ Letters, providing motivation for keen competition.
Simply having access to the telescopes is necessary but is not sufficient. The instrumentation has to work, and the data have to be saved in a form suitable for the observer to work on and eventually publish. A structure was created in Green Bank to accomplish this. There would be an engineering division to design and supervise the construction of telescopes. There would be an electronics division to develop advanced instrumentation which exploited the most recent technologies. There would be telescope operations since the typical visiting scientist would be unfamiliar with these structures. Binding it all together was a support staff who understood that the success of the observatory is totally dependent on the success of the observer, and who therefore were dedicated to helping the observer achieve that success. I was reminded of this just a few days ago when Mike Balister recalled an especially challenging night during which he was called out to each of the three telescopes in turn. There are many familiar names from these times – Bill Horne and Sidney Smith, Hein Hvatum, Sandy Weinreb, and Art Shalloway, Fred Crews and Bob Vance – so many that I am not able to mention them all, but as a group they worked hard to keep the telescopes at the cutting edge. This institutional ethos, if I may call it that, has been at the core of the Observatory and I regard it as the reason for the success of the NRAO.
Dave Hogg served as Assistant Director for Green Bank Operations from 1970-1974 and again from 1992-1993. He was involved in the development of the Green Bank Interferometer between 1962 and 1970, and was actively involved in the planning and development of the Green Bank Telescope (GBT). As a member of the GBT Commissioning group, David focused on correlator checkout, served on the team which defended NRAO in the GBT Arbitration proceedings, and was a member of the GBT Azimuth Track Review Panel. He became NRAO Scientist Emeritus upon retiring in 2005.
Events
Deadline for GBT Proposals
February 1, 2018
Proposals for Proposal Call 2018b for GBT Observers are due Feburary 1, 2018.
Summer Student Applications
Deadline for Application, February 1, 2018
For undergraduate students.
Remote Observer Training Workshops
January 15-16; May 24-25; September 17-18 Learn more.
Single Dish Training Workshop (Formerly Single Dish Summer School)
May 19-23
For grad students, post-docs and experts in other fields of astronomy. Learn more.
Pulsar Search Collaboratory Online Workshop
February 1 – March 15, 2018
For High school teachers and high school students Learn more.
Download the print (PDF) version of this newsletter.
This month marks both the 60th anniversary of the dedication of the National Radio Astronomy Observatory here in Green Bank, and the one-year anniversary of the creation of the Green Bank Observatory.
On October 17, 1957, the National Radio Astronomy Observatory came into existence. Over the past 60 years, the scientific discoveries and milestones achieved at the site have been momentous. The list of accomplishments is far too large to fit within one article, but they include: the first search for extraterrestrial intelligence; creation of the Drake equation; discovery of flat galactic rotation curves; first pulsar discovered in a supernova remnant; first organic polyatomic molecule detected in interstellar space; black hole detected at the center of the Milky Way; determination of the Tully-Fisher relationship; detection of the first interstellar anion; measurement of the most massive neutron star known; first high angular resolution image of the Sunyaev-Zel’Dovich Effect; discovery of only known millisecond pulsar in a stellar triple system; discovery of pebble-sized proto-planets in Orion, and the first detection of a chiral molecule in space.
Looking back just at the past year, our first as the Green Bank Observatory, the list of accomplishments is equally impressive. In the past year the first results from the Breakthrough Listen project were published; FLAG, the world’s most sensitive phased array feed receiver was commissioned; first data was released from the ammonia survey of the Gould Belt; two new molecules were detected in the ISM (HC5O and C7H); the first full season for observing with ARGUS and MUSTANG-2 was completed; and the recent Terzan 5 results directly measured the gravitational potential of a globular cluster for the first time. Looking to the other work done at and to support the Green Bank Observatory, the accomplishments of the past year include: hosting more than 2,000 visitors to view the solar eclipse, painting 84,000 square feet of the GBT, hosting 900 visitors at our annual open house (and launching 150 rockets in two hours that same day), releasing our new visitor reservations system, and hosting more than 30 film and news organizations.
The historical impact this facility has had on the scientific community is profound, and it is an impact that continues to grow. In the coming year we expect to see the first scientific results from our three new instruments, ARGUS, MUSTANG-2 and FLAG, and VEGAS, our GPU/FPGA backend, should begin pulsar observations. The legacy of our Observatory is great, but as the past year has proven, the potential for our scientific future is also fantastic.
Dr. Karen O’Neil,
Director, Green Bank Observatory
News
Striking New Radar View of the Lunar Surface
Researchers from the Smithsonian’s National Air and Space Museum used radio telescopes at the Arecibo Observatory and Green Bank Observatory to map the Moon with radar. The radar signals, transmitted from the Arecibo telescope and received at the Robert C. Byrd Green Bank Telescope, probed many meters below the surface of the Moon, just like ground-piercing radar on Earth. They revealed Lunar structures that can’t be seen in optical images because they’re hidden from view under the layer of dust and rubble that covers the Moon’s surface. The scientists are searching for unseen structures of Lunar geology such as lava flow complexes and buried craters.
The Green Bank Telescope (GBT) has been used to detect 15 brief but powerful radio pulses emanating from FRB 121102. These fast radio bursts (FRBs) are brief, bright pulses of radio emission from distant but unknown sources. Single FRBs have been detected from many directions on the sky, but this object is the only one known to repeat. More than 150 individual bursts have been detected from FRB 121102, which has been localized to a dwarf galaxy about 3 billion light years from Earth.
The discovery was made as part of the Breakthrough Listen project, an initiative to find signs of intelligent life in the Universe. Breakthrough Listen uses the Green Bank Telescope, and other instruments, to observe nearby stars and galaxies for signatures of extraterrestrial technology. When scientists found evidence that FRB 121102 occasionally produced repeated radio bursts, the project team at the University of California, Berkeley, added it to their list of targets.
In the early hours of Saturday, August 26, 2017, the Green Bank Telescope was pointed at FRB 121102 using a receiver tuned to frequencies of 4 – 8 GHz, much higher than any previous fast radio burst had been detected. Using a special instrument to break the data into billions of extremely fine frequency channels, the Breakthrough team accumulated 400 terabytes of data over a five-hour period. Analysis by Breakthrough Listen postdoctoral researcher Vishal Gaijar revealed the 15 new pulses.
Possible explanations for the repeating bursts range from outbursts from rotating neutron stars with extremely strong magnetic fields, to speculation that they are directed energy sources used by extraterrestrial civilizations to power spacecraft.
The Milky Way is chock-full of star clusters. Some contain just a few tens-to-hundreds of young stars. Others, known as globular clusters, are among the oldest objects in the Universe and contain up to a million ancient stars.
Green Bank Machine Shop Expands Production Capabilities
The Machine Shop in Green Bank recently took delivery on a new Haas VF-5/40 machining center.
The new machine has a slightly larger worktable and 5-axis capability (e.g., it moves in more directions during machining) making it a very capable, state of the art machine. The machine will be used to make high-precision receiver and telescope components.
Open Source Radio Telescopes
Over the past few years, advances in the development of software defined radio (SDR) have encouraged tinkerers to construct low-cost radio telescopes suitable for detecting emission from galactic neutral hydrogen. One of the first such systems was developed by REU students at Haystack Observatory in 2013.
Observatory staff became intrigued after an NRAO conference to discuss potential radio astronomy citizen science projects. This initial interest has expanded on several fronts over the past year.
First, retired NRAO scientist, Glen Langston, who has created several working prototypes in his home workshop, mentored EPO staff in constructing and documenting a feed horn telescope specific to the 21 cm hydrogen line using only readily available materials bought from home improvement chains, the local general store, and MiniCircuits, and then using the telescope to map hydrogen in the Galaxy.
This in-house expertise and documentation in turn formed the foundation for a unique NSF funded engineering internship experience for 12 rising college freshmen last July, who spent 2 weeks in residence at the Observatory to improve the initial design and further document their work. The internship produced two successful telescopes.
Meanwhile, the GBO partnered with West Virginia University to host an NSF funded a Research Experience for Teachers (RET) cohort of nine high school teachers. The focus of the RET experience was digital signal processing, and with the assistance of WVU engineering faculty, each teacher built their own 21 cm horn antenna, including the low noise amplifier!
Software to acquire and display the data was developed separately by each group using GNU Radio blocks as a starting point.
Finally, in a separate project, GBO high school intern Ellie White worked with Observatory staff to construct an instrument using SDR to measure low frequency ionospheric disturbances.
In an effort to spur community participation in SDR-Radio Astronomy applications, we created Open Source Radio Telescopes, where this initial documentation has been shared. There is a list-serve as well. For more information visit the website or contact Dr. Richard Prestage.
EPO Happenings
WV Science Public Outreach Team Workshop Trains Next Generation of Ambassadors
The West Virginia Science Public Outreach Team (WV SPOT), is an ambassador program that trains undergraduates from WV colleges and universities to go into K-12 schools and present engaging and interactive “shows” on science and engineering that is occurring in West Virginia.
Recently, 46 undergraduate students from across the State participated in a two-day workshop to prepare for their role as SPOT science ambassadors to K-12 students in the mountain state. With support of veteran SPOT ambassadors and Observatory staff, new recruits participated in training sessions enabling them to lead hands-on activities, learn effective public speaking techniques, and master the content of their chosen SPOT show during the weekend workshop.
Because they are successful college students – not that much older than the kids they present to – who go to school in West Virginia, SPOT ambassadors make a huge impression on the K-12 students they visit. Students can see themselves as future successful college students and they also learn that they don’t have to leave WV if they want to be a scientist or an engineer! Our shows feature the science going on at the Observatory, as well as NASA missions and additional shows that feature other kinds of science and engineering beyond space-themed presentations.
Our current ambassadors come from 7 different colleges across the state, and they travel far and wide to deliver interactive shows. Last year alone, ambassadors were able to present at schools in 24 different counties, reaching 3,525 students! Since WV SPOT’s inception in 2013, the program has reached 14,258 students.
Thanks to funding provided by grants from researchers at West Virginia University and Marshall University, and the West Virginia Space Grant consortium, student ambassadors receive modest payment for their outreach.
At the end of the weekend, 74% of the ambassadors felt more prepared to talk to students and teachers and 70% indicated they had learned more about science! It is no secret to us that this observatory is a place of inspiration, wonder, and science. The magic that surrounds the Green Bank Observatory, along with its ability to eliminate distractions helped the ambassadors find their voice in STEM.
Eclipse Viewing Event
The day the long anticipated Great American Eclipse arrived, so did over two thousand students, science buffs, and families, all streaming into the Green Bank Observatory with traffic lines backing up on both North- and Southbound lanes of Rt. 28/92.
Many people made this event a stunning success. The Science Center staff did their usual superb job of making visitors welcome and setting up fun activities, The Cafe’ and Cafeteria staff kept everybody fed, the Works group had the tents in place and the grounds looking great, and the rest of the staff volunteers handled everything from parking directions, items sales, activity staffing, to roving eclipse and site experts answering visitor questions.
Some statistics:
Estimated crowd size – 2,100 (one of the largest in the history of the Green Bank facility)
Eclipse glasses distributed – 1,961
Pizzas prepared – 126
Lunches served – 720
Hopefully this wonderful community experience will be replicated in 2024. Save those glasses!
Meet the Staff
Heatherly Recognized with Thomas K. Brennan Award
Astronomical Society of the Pacific announced its 2017 National Award recipients. Our own Sue Ann Heatherly received the prestigious Thomas J. Brennan Award, which is given to an individual demonstrating excellence in the teaching of astronomy at the high school level in North America.
When you think about the breadth of her reach to students all across the nation, the innovative educational programs she has developed and her pioneering of the education programs for both the NRAO and GBO, it is no wonder that the ASP took notice.
Sue Ann began her career in STEM education 31 years ago as a science teacher, but after attending a summer residential teacher enrichment program as a participant, she knew Green Bank was where she could make the greatest contribution to the field. Since joining the Observatory in 1989, Sue Ann has pioneered immersive, hands-on field trip opportunities such as the Radio Astronomer for a Day program that has served over 30,000 students. It is because of Sue Ann’s efforts and vision that we now have the Green Bank Science Center, its buses and bunkhouse as well as our public tour programs that have served over 600,000 since opening the doors 14 years ago. Sue Ann developed the residential, summer programs for West Virginia’s Governor’s School, Physics Inspiring the Next Generation, the nationally-recognized Pulsar Search Collaboratory, and the FirstTwo statewide collaboration supporting first-generation rural STEM students during their first two years at the college level, not to mention one-week to two-month teacher enhancement workshops. In addition to her own programs, she has built partnerships to host several successful on-site programs such as Star Quest Star Party, the Society for Amateur Radio Astronomer’s Conference and Chautauqua short courses for college teachers.
We asked Heather a few questions about her and the programs she has done.
You’ve put together so many successful programs over the years. Do you have a favorite?
I love anytime I have teachers here for a couple of weeks–they are my people! But, my favorite work we do is with our rising 9th graders. They are just at a remarkable age. These students are smart, fierce in their quest for knowledge, independent, and I haven’t been disappointed by them in all my years.
What is the biggest program delivery or development challenge you face?
It’s always very challenging to keep programs funded. You create this amazing program and then after your three years are up, you are faced with finding ways to keep these programs sustained over time.
From the standpoint of an educator professional in the field, what has made the biggest impact in STEM in the last 5 years?
Perhaps the most negative impact on STEM education has been the hard focus on standardized testing. It hasn’t been used in the right way for personalized improvement. It also inhibits the creativity of science teachers, who are among the most creative teachers I know. They are experimenters and tinkerers by nature and the more you can engage students in that and less checking off things that are going to be tested, the better.
On the positive side, I am really excited about the acknowledgement of STEM as vitally important at the local, state levels. Here in West Virginia, our last governor created a STEM council and brought together people to figure out how to improve STEM in the state. It gives us the opportunity to fit into statewide and national imperatives.
No interview would be complete without this very important question: What is your favorite lunch in the GBO cafeteria?
Hamburger Bean Casserole. I love it!
“There is no doubt that Sue Ann Heatherly has left an indelible mark on students and teachers she has mentored through her 31 years of dedication to impact the approach teachers have toward understanding astronomy.” Just as there is no doubt SA has left an indelible mark on this observatory and all those who work with her. Read more on the ASP’s website.
History: Special Commemorative Section
As we celebrate the 60th Anniversary of the dedication of the National Radio Astronomy Observatory and radio astronomy in Green Bank, we invite you to enjoy our brand new, interactive timeline on our website at greenbankobservatory.org/timeline-green-bank-observatory
We also commemorate other notable milestones:
1st Anniversary of Green Bank Observatory
30th Anniversary of Education Programs in Green Bank
80th Anniversary of the pioneering Grote Reber Telescope
For six decades now, Green Bank Observatory has been helping to fill in the vast blank spaces on our map of the universe through radio astronomy.
From detecting the first signal of an organic molecule in space to searching for low frequency gravitational waves from pulsars, Green Bank has been an integral part of radio astronomy and astrophysics research and discovery throughout its existence.
And for 60 years, West Virginians have celebrated this extraordinary facility. During the state’s centennial in 1963, the silhouette of the original 300-foot Green Bank radio telescope graced a special commemorative license plate. During the statehood quarter design competition in 2003, numerous entries featured the Green Bank Telescope.
Photos of the facility hang in classrooms and libraries across the state. An effort is underway to add Green Bank to UNESCO’s Astronomy and World Heritage Initiative.
The facility brings the world to West Virginia and we are proud to showcase our cutting-edge scientific equipment as well as our natural beauty. At the height of the Cold War in 1961, Russian scientists came to Green Bank for a symposium. High school students from every state visit Green Bank every summer as part of the National Youth Science Camp.
Researchers from institutions around the world rely on the radio telescopes at Green Bank for their work. Thousands of visitors each year enjoy the state-of-the-art Science Center.
And yes, Green Bank has been and remains a leading center for the search for extraterrestrial intelligence. The search began at Green Bank with Frank Drake and Project Ozma in 1960. We are proud of this fact, too, perhaps most of all because of what the search itself represents.
I think James Gunn, the author of the 1972 science fiction novel “The Listeners” about radio astronomy and the search for other life in the universe, said it well: “It may be that there is no one out there or if there is someone out there he will never speak to us or we to him, but our listening is an act of faith akin to living itself. If we should stop listening, we would begin dying and we would soon be gone, the world and its people, our technical civilization and even the farmers and peasants, because life is faith, life is commitment. Death is giving up.”
I have been honored to serve as president of West Virginia University, the state’s flagship, land-grant, research university, on two occasions almost 30 years apart. Based on that experience, I have found West Virginians to be determined, patient, resilient people.
Perhaps that is why Green Bank resonates so much with us. The monumental task of studying the universe in order to unlock its secrets requires determination, patience, and resilience. Even in the face of technical challenges, mixed signals, and financial setbacks, Green Bank perseveres.
Residents of West Virginia — a state born from the strife of the Civil War, beset by natural disasters, buffeted by economic downturns — can relate to that. That is why Green Bank is a great symbol for West Virginia.
As we celebrate this history, the future of Green Bank hangs in the balance. The National Science Foundation is in the midst of decreasing its funding for the facility. As someone immensely proud of Green Bank and its 60 years of scientific research, education, and outreach, I believe we must preserve and expand this essential place and continue its fundamental work.
Who knows what discoveries the next 60 years may hold? Let us keep listening. We must not give up.
30 Years of 40-ft Education Programs
In the midst of celebrating the 60th anniversary of the Observatory at Green Bank, it’s easy to overlook another anniversary. July, 2017 marks the 30th anniversary of educational programs at the Green Bank Observatory. In July 1987, the Green Bank facility opened its doors to 27 teachers in an experimental two-week summer institute, designed to introduce educators to a national research center. The following remembrance is from our Education Officer, Sue-Ann Heatherly.
The Forty Foot Telescope has been at the heart of the experiences we’ve offered teachers and students at Green Bank. Built in 1962 to make repeated observations of a small list of radio sources, it is an unabashedly old-fashioned telescope:
Data is recorded on a chart recorder;
There is no feed horn, no cryogenics, no computer;
There is no tracking ability. The Forty Foot is a transit telescope.
And yet, it is one of the most useful and productive instruments in radio astronomy! It is certainly true that the 40 Foot Telescope serves more users annually than all of the NRAO plus GBO telescopes combined! Here are a few notable observing stories from my years with the 40 Foot Telescope.
1. You found us! During that first summer, teacher teams used the 40 Foot to makes maps of the sky around Cygnus A and Virgo A, and to measure the telescope’s efficiency and beam shape. Our team decided to mimic the operation of the 300 Foot, nodding the 40 Foot north and south to collect more data in a shorter time-frame. As we nodded the telescope from north horizon to south, we noticed a huge bump in the chart recording trace. Excited to discover a huge radio source, we raced our chart recording back to the astronomers. They smirked a little bit and asked us to go back down to the telescope and see if it was still there. It was. And it was at midnight, at 3 AM, in fact every time we looked! That big bump occurred right as the telescope passed through the zenith. We had indeed detected a radio source, the Earth! We were picking up radiation from the ground! In that context did teachers learn about “spillover”.
2. We are not alone! Teachers mapping the Sagittarius A region in 1989 were startled to see the chart pen start jerking up and down … were they seeing rapidly fluctuating interference? They quickly switched on an audio speaker to hear a NutraSweet commercial originating, apparently, at the Galactic Center.
3. Sagittarius A! One summer, in the mid 1990s, both south limit switches failed and the telescope plowed into the ground. Rather than registering horror at this state of affairs, teachers and staff rejoiced alike because, at least for a short time, the 40 Foot could finally see the Galactic Center. (The 40 Foot’s southern limit is normally a frustrating ½ degree north of true center of our galaxy, Sagittarius A.) Luckily the hearty 40 foot sustained no permanent damage.
4. We are not alone – Part II. In January 1997, Glenville State College students discovered a signal of short duration (1.5 minutes) at the celestial location of RA 20:32 and Dec. 39.5 degrees. The source persisted through several days of observing, occurring at the same sky location each day.
Although Green Bank astronomers dismissed the signal as interference at first, its sidereal reoccurrence and the tenacity of the students soon had staff intrigued. Other observatories were asked about the phenomenon, and couldn’t identify it. Two weeks later the Glenville students returned to the Observatory, but this time to use the 140 Foot Telescope.
The signal was there!
Unfortunately, spectral analysis revealed a “spread spectrum” and the signal was eventually determined to come from a military satellite, which had a 2X sidereal orbit.
5. What’s that funny wire? For almost as long as the 40 Foot has been an educational telescope, Dan Reichart of UNC has been organizing his own educational camp. They rig up some pretty fancy recording equipment to the 40 foot to digitize the signals. A few years back they noticed a weird little wire poking out of the drive controller rack. As the teams cycled through the telescope they played with this little wire, pulling on it, trying to tuck it back in. Eventually, under closer inspection, they realized it was a mouse tail!
Those first summer institutes were good ones. The Observatory has continued the program and now, after 30 years, over 1300 K-12 teachers, 500 college faculty, and hundreds of K-16 students have graduated from what has affectionately been called: “Radio Astronomy Boot Camp”.
Some of those teachers have started their own programs for students, and some of those students are now astronomers or young science teachers bringing their students to Green Bank.
Thanks to Rich Bradley for working hard in 1987 to make the 40 foot functional for the first groups of teachers, and the telescope mechanics for keeping it that way, Carl Heiles for inspiring us to observe neutral hydrogen, a true staple of our educational programs for teachers and youth, Bill Radcliffe (do you remember the time you single-handedly took the front end off the telescope???), Nathan Sharp, and Dave Woody for coming to the rescue when the 40 Foot needed a technical swift kick, Skip Crilly for updating the telescope and getting rid of pesky RFI, and all of the astronomers who have enlightened teachers and students over the years.
Special gratitude goes out to Carl Chestnut, who was my Forty Foot partner in crime for many years and who is missed daily.
80 years of the Reber Telescope
The following is a little story about one of the early pioneers of radio astronomy, Grote Reber.
Grote Reber built the first radio telescope in his backyard in Wheaton, Illinois, a suburb of Chicago, where he lived with his mother. Grote was fascinated when he learned of Jansky’s discovery in 1933 of radio radiation from the Milky Way. Unable to find a job following up on Jansky’s discovery, he decided to study the “cosmic static” on his own, while at the same time working for a radio manufacturing company in Chicago.
He studied telescopes and optics and determined that a telescope based on a parabolic reflector would be the best for measuring radio waves from the Milky Way, if they existed. He was very meticulous and planned the project in great detail. In about 1937 he built a large reflecting parabolic dish with a receiver at the focal point of the parabola. He built the largest dish antenna that was possible with materials from the local builders supply store, about 31 feet in diameter.
It was assumed that the radiation would be due to thermal processes, thus the power would increase with shorter wavelength, so Grote designed a receiver for the shortest wavelength possible with the technology of the time, about 9 cm (3.3GHz). He took advantage of his contacts with electronics manufacturers to get the most advanced amplifier tubes.
He worked his day job, and at night surveyed the sky. He detected nothing at the 9 cm wavelength, so he redesigned his receiver for a longer wavelength, 33 cm.
Again nothing was detected from the Galaxy. Grote has written, “In a measure, it was disappointing. However, since I am a rather stubborn Dutchman, this had the effect of whetting my appetite for more.”
Reber redesigned his receiver for a longer wavelength of 187 cm (160 MHz), and improved the sensitivity by several factors of 10. Now he found it was very sensitive to man-made radio interference, especially from automobile spark plugs, but this quieted down after about 10 pm. He finally detected the Milky Way and proceeded to survey the radiation over much of the sky over several months. He then developed an even more sensitive receiver for 62 cm (480 MHz) with which he could also detect the Milky Way.
He found that the strength of the radiation from the Milky Way increased with longer wavelengths, contrary to what was expected for thermal radiation. It was not until the 1950s that the theory of synchrotron radiation was developed that explained the type of emission that came from the Milky Way.
Reber published his results both in Engineering journals and in Astronomy journals, and the science of radio astronomy was recognized as an important field of research. After World War II, some of the physicists and engineers that had worked on developing radar for wartime uses took up the study of radio astronomy. This led to the establishment of the National Radio Astronomy Observatory in Green Bank in 1957, along with similar efforts in several other countries.
In 1959, Reber was invited to be a visiting scientist at Green Bank. He spent about a year there where he supervised the re-assembly of his telescope on the Observatory grounds as an exhibition. He also had a replica of Jansky’s antenna constructed on the site, having found that the Bell Telephone Laboratories still had the original drawings.
In 1972 the Reber Telescope was put on the National Register of Historic Places and in 1995 he donated his equipment to Green Bank. You can see his 1930s -40s vintage receivers and recording equipment in the Science Center today.
Reber is an inspiration to astronomers for his dogged persistence in carrying out his research, and also for the meticulous planning that characterized everything he did. He once advised a student,
“Pick a field about which very little is known and specialize in it. But don’t accept current theories as absolute fact. If everyone else is looking down, look up or in a different direction. You may be surprised at what you will find.”
References:
G.Reber: “Early Radio Astronomy at Wheaton, Illinois,” Proc.IRE, Vol 46, Jan 1958.
G.Reber: “A Play Entitled The Beginning of Radio Astronomy”, J.Roy.Astron.Soc.Canada, vol82, No.3, 1988.
J. Kraus, “Grote Reber, founder of Radio Astronomy”, J.Roy.Astron.Soc.Canada vol 82, No.3, 1988.
Events
Guest Speaker Series
Oct. 17th
Currect staff members and retirees will present Celebrating 60 Years of Radio Astronomy in Green Bank
Oct. 25th
Dr. Fran Bagenal, University of Colorado Laboratory for Atmospheric and Space Physics, will present Exploration of the Outer Solar System: New Horizons at Pluto and Juno at Jupiter
Oct. 27th
2017 Jansky Lectureship Awardee Dr. Bernie Fanaroff will present Observing the Universe from Africa: Linking radio astronomy and development
Nov. 2nd
Sarah Scoles, author of Making Contact: Jill Tarter and the Search for Extraterrestrial Intelligence, will present A History of False Alien Positives followed by a book-signing event
Transformative Science Workshop Updates
October 16 – 20
Big Questions, Large Programs, and New Instruments: With new instruments and excellent performance, the 100m Green Bank Telescope is only just reaching its full potential. On this 60th anniversary of the ground breaking for the Green Bank Observatory, we are holding a workshop looking toward the next 10, 20, and even 60 years of the Green Bank Observatory, and invite the community to attend and aid us in planning the future. For more information, please visit: greenbankobservatory.org/transformative-science/
Career Opportunities
Facilities Engineer (4266)
Green Bank Observatory is looking for a Facilities Engineer. This person will be responsible for the coordination and oversight of all new construction and special projects that affect the site or facility and overall maintenance and upgrade of this scientific research facility containing laboratories, offices, shops, residences, vehicles, roads, water and wastewater facilities, power distribution systems and radio telescopes. This position will also head the Plant Maintenance Division and coordinate the work of all crafts/trades involved. Read the full description and apply online.
Software Engineer I-IV (Open Rank)
We are also seeking an entry level or early career software engineer to join the Green Bank Observatory (GBO) Software Development Division (SDD). The division’s primary focus is maintaining and upgrading the subsystems supporting the operation of the Robert C. Byrd Green Bank Telescope. The major subsystems include: telescope monitor and control, telescope scheduling, data reduction, and data archiving. The team also develops new software to meet challenges posed by new observing paradigms and state of the art instrumentation. Job classification and compensation will be commensurate with education and experience.
ESSENTIAL DUTIES AND RESPONSIBILITIES
Using prescribed methods, researches, conducts or coordinates detailed phases of software engineering work as assigned. Performs work that involves conventional software engineering practices. The successful candidate will collaborate with members of the Software, Electronics and Science Divisions to contribute to full life cycle development of web and systems applications supporting GBO operations. Opportunities also exist to develop software in other radio astronomy-related domains including embedded systems, FPGA systems, software defined radio, and machine learning. Full description and application can be found online.
