The Observer – Special AAS 235 Edition

Note from the Director

By the time this newsletter reaches publication, we will have entered into the 2020’s, and will likewise have marked the 6th decade of radio astronomy and education programs here in Green Bank, West Virginia.

Looking back, the past decade was one of significant change. The 100-m Green Bank Telescope reached its design goals for high frequency science, achieving a 30% surface efficiency at 90 GHz, and four new multi-pixel instruments were developed and deployed on the telescope. During the past decade approximately 65,000 hours of telescope time was spent making discoveries – including new complex molecules in space; determining the location of the first repeating fast radio burst; mapping the bridge of neutral hydrogen between M31 and M33; finding the most massive neutron star yet discovered; and many, many more.

Looking forward, the GBT shows incredible scientific promise for the next decade. Already three new instruments are underway – a wide-band feed optimized for pulsar timing studies, a laser-based system for improving the telescope’s performance at high frequency, and new RFI excision techniques to maximize the scientific output in this era of increased usage of the radio spectra.
Please join us at a special splinter session to be held at the 235th AAS meeting in Hawaii. We will take this time to work with the greater radio astronomy community, beginning to make the plans for a suite of instruments to follow, and ensuring the Green Bank Telescope and the Green Bank Observatory meet the needs of the U.S. astronomy community for many years to come.

Wishing you a fantastic and science filled new decade,
Karen O’Neil
Green Bank Observatory Director

2020 Calendar

January 2
Call for GBT Proposals 2020B Semester Released

January 22-24
Observer Training Workshop

February 3
Deadline for ALL Summer Student Opportunities
February 3
Deadline for GBT Proposals 2020B Semester

May 11-15
Single Dish Training School
May 18-20
Observer Training Workshop

June 12-14
Space Race Rumpus
June 17-20

July TBD
Call for GBT Proposals 2021A Semester Released
July 13-23
Pulsar Search Collaboratory (PSC) Camp

July 19-August 1
July 26-August 8
Physic Inspiring the Next Generation (PING) Camp

August 3
Deadline for GBT Proposals 2021A Semester

October 4
Science Center Open House & Family Science Day
October 13-15
Observer Training Workshop

The complete calendar of Observatory events can be found online.

Green Bank Observatory Call for Proposals: 2020B Semester

The Green Bank Observatory invites scientists to participate in the 2020B Semester Call for Proposals for the Green Bank Telescope (GBT). The entire proposal call can be found online.

The submission deadline for Semester 2020B proposals is Monday, 3 February 2020, at 17:00 EST (22:00 UTC).

Receiver availability for the 2020B semester will be determined by those highly ranked proposals accepted in Group A.


Beginning with the 2020B semester the GBT will only accept large proposals once per year at the February proposal deadlines. We will no longer accept GBT large proposals at the August proposal deadlines. There will not be a large proposal call for 2021A for the GBT. The next large proposal deadline for the GBT after this call will be for the 2021B semester. This new policy ensures equality for the reviews of all large proposals that can be scheduled across a full year.

Green Bank Observatory at AAS

Splinter Session:
The Advanced Green Bank Telescope: Planning for the Next Decade

Jan 7, 9:30 – 11:00 AM, Room 301B

Looking toward the scientific priorities in the community for the next decade, Green Bank Observatory is planning and developing capabilities for the Green Bank Telescope (GBT) to advance its scientific output. With a new cooperative agreement for operations of the Green Bank Observatory in place, the Observatory is soliciting community feedback to help maximize the telescope’s scientific potential in an era of reduced open skies availability. The feedback that is provided during this Splinter Session will help shape the agenda for more focused meetings that will be held at the Green Bank Observatory over the next year. Additional opportunities to provide feedback will be provided for those who cannot attend this Splinter Session.

Participation is welcome from all scientists whose research may benefit from the use of the Green Bank Observatory and especially encouraged for early-career scientists and new GBT users.

The Green Bank Observatory and the GBT are featured or mentioned in almost 90 presentations and session at the AAS. A list of these has been assembled using the AAS database and can be found on this site. This list is current as of the publication of this newsletter.

News and Updates

Progress on LASSI

The Laser Antenna Surface Scanning Instrument (LASSI) project aims to improve Green Bank Telescope efficiency for observations at frequencies above 25 GHz. Using a commercial laser scanner purchased in December 2018, the Green Bank Observatory is implementing a measurement system that will detect thermal deformations of the telescope surface, and correct them using the actuators that support each panel. The Observatory team has been conducting experiments, preparing algorithms, and reviewing the LASSI design. The experiments performed so far have shown how the GBT surface changes between night and day, and have been used to test the performance of the algorithms. In these tests, LASSI has been able to detect surface deformations having an amplitude of 75 microns.

LASSI – Primary spherical optical aberration reproduced by the active surface of the GBT as observed by the terrestrial laser scanner.

The LASSI project underwent a Preliminary Design Review (PDR) in September 2019 using a panel of independent experts that assessed the project and its progress to date. LASSI successfully passed the PDR, and was given an endorsement by the review panel to proceed to a detailed design phase of the project.

LASSI (“Enhancing GBT Metrology to support high resolution 3mm molecular imaging for the U.S. Community”) is supported by the National Science Foundation under Award Number AST-1836009.

Learn more about the project by visiting poster #175.16 during the 235th winter AAS.

Progress on the New Ultra-Wideband Receiver

Artist concept of the ultra-wideband receiver with feedhorn. (GBO/AUI/NSF)

Work continues on a new 0.7-4 GHz ultra-wideband receiver for the GBT. Computer modeling is complete and machining of the individual pieces that will comprise the receiver feedhorn is underway in the Green Bank Observatory machine shop. Engineers at the Observatory are also fabricating the final version of the large window that will hold the cryogenic components of the receiver under vacuum while still allowing radio signals to pass. Testing continues on various electronic components, with laboratory results matching the specifications expected from the manufacturers. A large number of high performance computers have also been ordered and are undergoing setup and configuration for testing the new capabilities of the expanded VEGAS backend that will process data produced by the receiver. Scientific commissioning is planned for early 2021. An update on this work will be provided at the 235th AAS Meeting Splinter Session.

This project is funded in part by the Gordon and Betty Moore Foundation through Grant GBMF7576 to Associated Universities Inc., in support of the work of the Green Bank Observatory and NANOGrav Physics Frontiers Center.

New Wideband Digital Technology and Interference Excision for Radio Astronomy

Luke Hawkins and Satori Chin inspect a circuit board
GBO Engineer Luke Hawkins and Allegheny College computer science major Satori Chin inspect a circuit board to be used in the NSF grant award project. (NSF/AUI/GBO)

Observatory scientists and engineers are developing the next generation of digital signal processing and radio frequency mitigation techniques for ultra-wide bandwidth systems. The digital engineering group has completed early characterization and testing of a 10.25 Gsamp/s analog-to-digital converter from Analog Devices, and are beginning the design of a custom circuit board that will interface this ADC with state-of-the art Xilinx signal processing hardware. Firmware for controlling and processing the data produced by these new devices is also under development at GBO and at other sites through CASPER. Staff are also exploring innovative new methods for radio frequency interference identification and mitigation. During the summer of 2019, nearly 20 TB of baseband voltage data were recorded for offline processing using a variety of interference mitigation techniques. These include statistical identification of RFI through the use of spectral kurtosis and cyclostationary statistics, and through the use of machine learning. These techniques are currently undergoing rigorous quantitative analysis and comparison with data that has been processed using traditional interference mitigation techniques. An update on these efforts will be provided at the 235th AAS Meeting Splinter Session.

This work is supported by the National Science Foundation grant number 1910302.

Chime comes to the Observatory

The Canadian Hydrogen Intensity Mapping Experiment (CHIME) antenna array at the Green Bank Observatory. (GBO/AUI/NSF)

After a summer of planning, a CHIME prototype array is taking shape on the Observatory campus as most of the 12 planned antennas are being installed on their mounts. Once completed, the installation at Green Bank will be used by West Virginia University in partnership with McGill University in an attempt to correlate Fast Radio Burst (FRB) signals detected by the Canadian Hydrogen Intensity Mapping Experiment (CHIME) Telescope in British Columbia, Canada with signals received here. FRBs are extremely short, but bright, flashes of radio emission. Their origin is a mystery but they seem to be coming from far outside the Milky Way. Perhaps a thousand hit the Earth each day, each from a random direction.

The CHIME antenna is a powerful instrument for detecting FRBs because it can see a huge part of the sky, but it is not able to locate the position of an FRB accurately. That is where the antennas at the observatory come in. The Green Bank Observatory antennas will observe the same part of the sky as CHIME. Once a strong burst is detected in Canada, astronomers will look for correlated data from the Observatory dishes. If the signal is present in the Green Bank data, the location of the FRB will be determined much more precisely.

The 12 antennas at Green Bank are not nearly as sensitive as the CHIME antenna in BC, so only the strongest FRBs are likely to be seen by both instruments. This proof-of-concept, however, is the first step towards a possible much larger array in Green Bank consisting of a smaller version of the CHIME “half-pipe” antenna and as many as 64 more rugged versions of the six-meter antennas currently being installed for the prototype. Jon Cooper and Jody Bolyard have started the environmental approval process for the large array and Green Bank Observatory is planning a proposal to the CHIME collaboration for inclusion in a current funding request to build these antennas at as many as three of these secondary locations (Green Bank, Owens Valley, and Ontario, CN). Green Bank is one of their first choices due to the infrastructure and staff here to support such an installation and the benefits of the NRQZ.

The GBO efforts for the prototype and larger array are primarily focused on siting the antennas, overseeing installation, providing power, data, and timing connections, and housing the backend.

Green Bank Observatory’s Post Docs

The Green Bank Observatory is home to four post doctoral fellows in 2019. They have been working on a variety of projects on campus and presenting their research at many conferences around the world.

Post doctoral fellows Natalie Butterfield (above) and Will Armentrout (below) lead visitors on a tour of the GBT. (GBO/AUI/NSF)

This fall, Dr. Natalie Butterfield attended a Galactic Center conference in Yokohama, Japan. This conference brought together scientists around the globe whose research focuses on the center of the Milky Way galaxy. The Galactic Center conference is held once every three years, and it was notable to see how the science goals of the field have shifted in this short time scale. The future of Galactic Center research focuses on the inflow and outflow of gas across the inner region of the galaxy to better understand galaxy evolution.

Dr. Will Armentrout presented GBT observations from the Argus receiver (74-116 GHz) at several conferences this Fall. He mapped molecular gas surrounding the most distant known Galactic star forming regions in the Outer Scutum-Centaurus Spiral Arm (OSC). The OSC is the most distant known molecular spiral arm, tracing out the outer first Galactic quadrant. He also presented this work as a seminar at the Harvard-Smithsonian Center for Astrophysics. The conferences included From Gas to Stars: The Links Between Massive Star and Star Cluster Formation in York, UK; Crete III: Through Dark Lanes to New Stars in Heraklion, Crete, Greece; the Harvard-Heidelberg Star Formation Workshop in Cambridge, MA; and the .Astronomy (pronounced “dot astronomy”) conference at the University of Toronto, CA.

Post doctoral fellow Pedro Salas at dish level on the GBT. (GBO/AUI/NSF)

Dr. Pedro Salas, a recent arrival from Leiden University, works on topics of ionized gas in the Milky Way, star formation, high-angular resolution, and instrumentation of the GBT. He has an active role in the Laser Antenna Surface Scanning Instrument (LASSI) project, which aims to improve GBT efficiency for observations at frequencies above 25 GHz. Learn more about the project by visiting poster #175.16 presented by Dr. Salas during the 235th AAS conference.

Welcome to Dr. Charles Romero, Green Bank’s Newest Post Doc

Charles received his PhD in astronomy from UVA, where he worked with Brian Mason studying galaxy clusters with the MUSTANG instrument on the GBT. Subsequently, he was a post doc at IRAM, Grenoble, where he helped commission the NIKA2 receiver on the IRAM 30m telescope. Now he is at the University of Pennsylvania and the GBO working with MUSTANG-2, supporting the instrument as well as continuing investigations of galaxy clusters.

Warm Ionized Medium in Galaxies: 1999 & 2019

This fall, nearly 40 scientists from across the country returned to Green Bank 20 years after the first Warm Ionized Medium in Galaxies workshop was held in 1999. The warm ionized medium, also called diffuse ionized gas, is a major component of the Galactic interstellar medium and is clearly important in other galaxies as well. In the twenty years since our previous workshop, it still remains a challenge to understand the ionization, heating, cooling and overall dynamics of this gas. With several new Galactic surveys, a wealth of extragalactic data, and advances in theoretical and computational models in the past few decades a workshop to reevaluate our understanding of the warm ionized medium was timely.

Information on the proceedings can be found here

2020 Frank Drake Lectureship Winner Selected

The Frank Drake Lectureship award recognizes individuals from the sciences, arts or humanities for their contributions to advancing human knowledge and creativity in the scientific realm. The 2020 recipient of this honor is Dr. Alyssa Goodman, based at Harvard University where she is the Robert Wheeler Willson Professor of Applied Astronomy and co-Director for Science at the Radcliffe Institute for Advanced Study. She is also a Research Associate of the Smithsonian Institution.

The time and date of her lecture, which is free and open to the public and held in the auditorium of the Green Bank Science Center, will be announced in 2020. The lecture will also be streamed live via social media platforms and a recording will be available for viewing afterwards.

Summer Student Research Assistantships Applications Open

The application system for 2020 summer positions will become available in December 2019, and applications for 2020 summer positions will be due on February 3, 2020.

There are several types of opportunities available and posts at Green Bank include housing and a stipend. Students who are interested in Astronomy and have a background in Astronomy, Physics, Engineering, Computer Science, and/or Math are preferred. The same on-line application form is used for all three programs, which can be accessed here.

Applicants from members of underrepresented groups in STEM are strongly encouraged. We have a commitment to providing an inclusive, educational and exciting experience for all young scientists.

Research Education and PING Mentors have the best Summers! (GBO/AUI/NSF)

Summer students who would like to encourage the next generation of students can also opt in to being a PING: Physics Inspiring the Next Generation Camp Mentor to rising 9th graders interested in STEM. This program happens during Green Bank Observatory summer student experiences, be sure to select the “PING” option on the application when completing.

Physics Inspiring the Next Generation (PING) Summer Camp

July 26-August 5, 2020

Physics Inspiring the Next Generation (PING): Investigating the Cosmos is a collaboration between the National Society of Black Physicists (NSBP), and Green Bank Observatory to expose traditionally underrepresented minorities (URM) to science and engineering with a focus on physics and radio-astronomy. While the program targets specifically two former White House initiatives, My Brother’s Keeper which is working to address the education needs of young men of color, and a second effort to promote interest in science among girls, all current 8th graders are welcome to apply.

Students will be on location in Green Bank, immersed in the research activities of this national research center. While in residence, students will work in small teams supported by an undergraduate student mentor and a staff scientist (astronomer, physicist, engineer, etc.) to conduct research by observing the universe with a 40-foot diameter radio telescope. Supplemental educational activities, including bench experiences building electronic circuits, and coding activities complement the primary research theme. In addition, fun whole group activities like swimming, hiking, and biking take place on the Observatory campus under the supervision of staff.

Applications available online now. The deadline to apply is April 30, 2020.

Apprenticeships/Internships, Summer Jobs & Permanent Employment

The Observatory offers apprenticeships and internships on a rolling basis. These positions are available for a wide range of positions, from machinists, mechanics, and trades to engineering, computing, and science.

The Observatory hires many summer roles, from seasonal positions in telescope maintenance and painting, to tour guides for the Science Center. Applications open in late winter, and this is the perfect opportunity for a wide range of job seekers from recent high school graduates, to undergraduate and graduate students, to retirees, to see what it’s like to work in Green Bank.

Over the next several years, the Observatory will be hiring a number of full-time, permanent positions. Keep an eye on our employment page to apply for these opportunities. Green Bank, West Virginia is an inclusive, creative, and tight-knit community. Our award winning staff come from the surrounding area, the country, and around the world, and they are proud to call this place home.

More information about our apprentice program and careers can be found online.

Baruch Blumberg Visiting Fellowship in Astrobiology at the Green Bank Observatory

Dr. Baruch (Barry) Blumberg, Nobel Laureate and first Director of the NASA Astrobiology Institute. Image courtesy: NASA

The Green Bank Observatory is seeking applicants for a visiting Fellowship in Astrobiology or related topics. The Fellowship includes a stipend, housing at the Observatory, and support for relocation. It is intended to support an established researcher for a summer in residence at the GBO but could also be used for a sabbatical at Green Bank during other times of the year.

This Fellowship is named in honor of Dr. Baruch Blumberg: Nobel Laureate, first Director of the NASA Astrobiology Institute, and President of the American Philosophical Society from 2005 until his death in 2011. The Fellowship is made possible through a grant from Unither Bioelectronique, where Blumberg was Chairman of its corporate parent’s Scientific Advisory Board.

The deadline for applications is 17 February 2020. Further information and applications materials can be found online.

Welcome New Staff

Dr. Walter Klahold, microwave engineer in the Electronics Division. (GBO/AUI/NSF)

Dr. Walter Klahold joined the Observatory team this fall as a microwave engineer in the Electronics Division. He comes to West Virginia from a post-doctoral position at Montana State University after graduating from the University of Pittsburgh with a PhD degree in physics. Walter’s interests up to this point have been primarily geared towards low temperature solid state physics and optics. He’ll be using his background in these areas to design a new cryogenic X-band receiver as well as providing support for some of the receivers currently active in the Green Bank Telescope.

Congratulations to Green Bank Staff for NASA Group Achievement Award

Congratulations to Marty Bloss, Amber Bonsall, Frank Ghigo, Toney Minter, and Galen Watts who were recognized as part of a 2019 NASA Group Achievement Award for their contributions to the InSight EDL Communications with JPL. This award was accepted on behalf of the group by Sandy Krasner at a NASA Honor Awards ceremony held at JPL this fall.

Green Bank Observatory in the News

2019 Media Award from the West Virginia State Tourism Board.

The Observatory receives many press requests each month and is a regular feature in regional and national news outlets, from The New York Times to the Washington Post. This year the Observatory was honored with an award from West Virginia State Tourism for Best Earned Media Coverage in the state.

Accessing Green Bank Observatory Resources

The Observatory has many resources available for scientists, educators, and the general public.

2020 Facilities Booklet

A PDF of our facilities booklet highlighting our science, instruments, and campus is available for download here.

2020 Science Center Brochure inside spread
2020 Science Center Brochure

A PDF of our 2020 Science Center brochure is available here on our Visit page.

Flickr photos for Observatory fans!

Need Photos? Hundreds of photos of Green Bank’s instruments, including the GBT, along with archival images, and images of our facilities and events, are available on our Flickr site.

2019 Publications

As of mid-December 2019 over 70 papers citing the Green Bank Observatory or GBT are in publication. The complete list can be accessed here.

Green Bank Observatory in AAS Presentations

This list has been assembled using the AAS database and is current as of the printing of this newsletter.

Presentations with Observatory staff as lead are highlighted in green.

Instrumentation Presentations

109.09. “Systems Engineering Study on a Green Bank Observatory Data Center” (K. Sleet)

109.30. “High Time-Resolution Radio Frequency Interference and Single Pulse Pulsar and FRB Detection using Machine Learning Semantic Segmentation” (M. Hawkins, et al.)

175.17. “Designing and testing an ultra-wideband receiver for the Green Bank Telescope” ( A. Bulatek, et al.)

175.18. “Ultra-wideband Digital Technologies for the Green Bank Telescope” (R. S. Lynch, et al.)

175.175. “LASSI: keeping the Green Bank Telescope in shape”
(P. Salas, et al.)

272.17. “Argus144: Wide-Field, High Resolution 3mm Molecular Imaging of Star-Forming Regions” (D. Frayer, et al.)

277.05. “Green Bank Planetary Radar System” (A. Bonsall)

364.23. “The Green Bank Array – Science from Ten ngVLA Antennas at the GBT” (W. Armentrout, et al.)

451.04. “A Beam-Forming Receiver for the GBT at 23 GHz”
(J. Skipper et al.)

See a list of all of the presentations at the 234th AAS meeting which primarily relay on data, instrumentation, or programs at Green Bank Observatory.

If you are attending the AAS in Honolulu, Hawai’i this January, be sure to visit the Green Bank Observatory booth in the National Science Foundation section (603) in the conference exhibit hall.

Floor plan of the exhibit hall – the Green Bank Observatory booth is in the NSF area (603).