Dr. Geoffrey Bryden Profile

Dr. Geoffrey Bryden

Research Scientist at Jet Propulsion Lab

SPIE Involvement:

Author

Geoffrey Bryden is an astronomer at the Jet Propulsion Laboratory (JPL). His research focuses on the detection and characterization of planetary systems beyond the Solar System, in particular the debris left over after planets form. He received his PhD in astrophysics from the University of California in 1999.

SPIE Journal Paper | 27 December 2022 Open Access

Hyperion: the origin of the stars. A far UV space telescope for high-resolution spectroscopy over wide fields

Erika Hamden, David Schiminovich, Shouleh Nikzad, Neal Turner, Blakesley Burkhart, Thomas Haworth, Keri Hoadley, Jinyoung Serena Kim, Shmuel Bialy, Geoff Bryden, Haeun Chung, Nia Imara, Rob Kennicutt, Jorge Pineda, Shuo Kong, Yasuhiro Hasegawa, Ilaria Pascucci, Benjamin Godard, Mark Krumholz, Min-Young Lee, Daniel Seifried, Amiel Sternberg, Stefanie Walch, Miles Smith, Stephen Unwin, Elizabeth Luthman, Alina Kiessling, James McGuire, Mina Rais-Zadeh, Michael Hoenk, Thomas Pavlak, Carlos Vargas, Daewook Kim

JATIS, Vol. 8, Issue 04, 044008, (December 2022) https://doi.org/10.1117/12.10.1117/1.JATIS.8.4.044008

KEYWORDS: Stars, Ultraviolet radiation, Clouds, Far ultraviolet, Space telescopes, Fluorescence, Molecules, Equipment, Galactic astronomy, Spectroscopy

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SPIE Journal Paper | 4 June 2021 Open Access

Starshade Rendezvous: exoplanet orbit constraints from multi-epoch direct imaging

Andrew Romero-Wolf, Geoffrey Bryden, Greg Agnes, Jonathan Arenberg, Samuel Case Bradford, Simone D'Amico, John Debes, Matt Greenhouse, Renyu Hu, Steve Matousek, Jason Rhodes, John Ziemer

JATIS, Vol. 7, Issue 02, 021219, (June 2021) https://doi.org/10.1117/12.10.1117/1.JATIS.7.2.021219

KEYWORDS: Planets, Stars, Exoplanets, Imaging systems, Signal to noise ratio, Observatories, Telescopes, Target detection, Space telescopes, Monte Carlo methods

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SPIE Journal Paper | 9 January 2021 Open Access

Starshade rendezvous: exoplanet sensitivity and observing strategy

Andrew Romero-Wolf, Geoffrey Bryden, Sara Seager, N. Jeremy Kasdin, Jeff Booth, Matt Greenhouse, Doug Lisman, Bruce Macintosh, Stuart Shaklan, Melissa Vess, Steve Warwick, David Webb, John Ziemer, Andrew Gray, Michael Hughes, Greg Agnes, Jonathan Arenberg, S. Case Bradford, Michael Fong, Jennifer Gregory, Steve Matousek, Jason Rhodes, Phil Willems, Simone D'Amico, John Debes, Shawn Domagal-Goldman, Sergi Hildebrandt, Renyu Hu, Alina Kiessling, Nikole Lewis, Maxime Rizzo, Aki Roberge, Tyler Robinson, Leslie Rogers, Dmitry Savransky, Chris Stark

JATIS, Vol. 7, Issue 02, 021210, (January 2021) https://doi.org/10.1117/12.10.1117/1.JATIS.7.2.021210

KEYWORDS: Planets, Exoplanets, Stars, Telescopes, Signal to noise ratio, Spectroscopy, Target detection, Observatories, Sensors, Point spread functions

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Proceedings Article | 24 July 2018 Presentation + Paper

The HOSTS survey for exo-zodiacal dust: preliminary results and future prospects

S. Ertel, G. Kennedy, D. Defrère, P. Hinz, A. Shannon, B. Mennesson, W. C. Danchi, C. Gelino, J. M. Hill, W. Hoffman, G. Rieke, E. Spalding, J. Stone, A. Vaz, A. Weinberger, P. Willems, O. Absil, P. Arbo, V. Bailey, C. Beichman, G. Bryden, E. Downey, O. Durney, S. Esposito, A. Gaspar, P. Grenz, C. Haniff, J. Leisenring, L. Marion, T. McMahon, R. Millan-Gabet, M. Montoya, K. Morzinski, E. Pinna, J. Power, A. Puglisi, A. Roberge, E. Serabyn, A. Skemer, K. Stapelfeldt, K. Y. L. Su, V. Vaitheeswaran, M. Wyatt

Proceedings Volume 10698, 106981V (2018) https://doi.org/10.1117/12.2313685

KEYWORDS: Stars, Planets, Calibration, Statistical analysis, Exoplanets, Space telescopes, Nulling interferometry, Astronomy, Telescopes, Interferometry

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The presence of large amounts of dust in the habitable zones of nearby stars is a significant obstacle for future exo-Earth imaging missions. We executed the HOSTS (Hunt for Observable Signatures of Terrestrial Systems) survey to determine the typical amount of such exozodiacal dust around a sample of nearby main sequence stars. The majority of the data have been analyzed and we present here an update of our ongoing work. Nulling interferometry in N band was used to suppress the bright stellar light and to detect faint, extended circumstellar dust emission. We present an overview of the latest results from our ongoing work. We find seven new N band excesses in addition to the high confidence confirmation of three that were previously known. We find the first detections around Sun-like stars and around stars without previously known circumstellar dust. Our overall detection rate is 23%. The inferred occurrence rate is comparable for early type and Sun-like stars, but decreases from 71^{+11 -20}% for stars with previously detected mid- to far-infrared excess to 11^{+9 -4}% for stars without such excess, confirming earlier results at high confidence. For completed observations on individual stars, our sensitivity is five to ten times better than previous results. Assuming a lognormal luminosity function of the dust, we find upper limits on the median dust level around all stars without previously known mid to far infrared excess of 11.5 zodis at 95% confidence level. The corresponding upper limit for Sun-like stars is 16 zodis. An LBTI vetted target list of Sun-like stars for exo-Earth imaging would have a corresponding limit of 7.5 zodis. We provide important new insights into the occurrence rate and typical levels of habitable zone dust around main sequence stars. Exploiting the full range of capabilities of the LBTI provides a critical opportunity for the detailed characterization of a sample of exozodiacal dust disks to understand the origin, distribution, and properties of the dust.

Proceedings Article | 6 July 2018 Paper

UKIRT under new management: status and plans

K. Hodapp, T. Kerr, W. Varricatt, R. McLaren, D. Lonborg, D. H. Hall, S. Jacobson, J. Bruursema, S. Dahm, B. Dorland, J. Munn, F. Vrba, J. Dempsey, Y. Shvartzvald, G. Bryden, B. S. Gaudi, C. Beichman, S. Calchi Novati, C. Henderson, S. Jacklin, K. Stassun, M. Penny, Mike Irwin, Andy Lawrence

Proceedings Volume 10700, 107002Z (2018) https://doi.org/10.1117/12.2311923

KEYWORDS: Telescopes, Astronomy, Observatories, Imaging spectroscopy, Infrared telescopes, Near infrared, Cameras, Sensors, Planets, Detector arrays

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Proceedings Article | 8 August 2016 Paper

Enabling the direct detection of earth-sized exoplanets with the LBTI HOSTS project: a progress report

W. Danchi, V. Bailey, G. Bryden, D. Defrère, S. Ertel, C. Haniff, P. Hinz, G. Kennedy, B. Mennesson, R. Millan-Gabet, G. Rieke, A. Roberge, E. Serabyn, A. Skemer, K. Stapelfeldt, A. Weinberger, M. Wyatt, A. Vaz

Proceedings Volume 9907, 990713 (2016) https://doi.org/10.1117/12.2233397

KEYWORDS: Exoplanets, Stars, Telescopes, Interferometers, Mid-IR, Nulling interferometry, Planets, Solar system, Space telescopes, Coronagraphy

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NASA has funded a project called the Hunt for Observable Signatures of Terrestrial Systems (HOSTS) to survey nearby solar type stars to determine the amount of warm zodiacal dust in their habitable zones. The goal is not only to determine the luminosity distribution function but also to know which individual stars have the least amount of zodiacal dust. It is important to have this information for future missions that directly image exoplanets as this dust is the main source of astrophysical noise for them. The HOSTS project utilizes the Large Binocular Telescope Interferometer (LBTI), which consists of two 8.4-m apertures separated by a 14.4-m baseline on Mt. Graham, Arizona. The LBTI operates in a nulling mode in the mid-infrared spectral window (8-13 μm), in which light from the two telescopes is coherently combined with a 180 degree phase shift between them, producing a dark fringe at the location of the target star. In doing so the starlight is greatly reduced, increasing the contrast, analogous to a coronagraph operating at shorter wavelengths. The LBTI is a unique instrument, having only three warm reflections before the starlight reaches cold mirrors, giving it the best photometric sensitivity of any interferometer operating in the mid-infrared. It also has a superb Adaptive Optics (AO) system giving it Strehl ratios greater than 98% at 10 μm. In 2014 into early 2015 LBTI was undergoing commissioning. The HOSTS project team passed its Operational Readiness Review (ORR) in April 2015. The team recently published papers on the target sample, modeling of the nulled disk images, and initial results such as the detection of warm dust around η Corvi. Recently a paper was published on the data pipeline and on-sky performance. An additional paper is in preparation on β Leo. We will discuss the scientific and programmatic context for the LBTI project, and we will report recent progress, new results, and plans for the science verification phase that started in February 2016, and for the survey.

Proceedings Article | 4 August 2016 Paper

Making high-accuracy null depth measurements for the LBTI exozodi survey

Bertrand Mennesson, Denis Defrère, Matthias Nowak, Philip Hinz, Rafael Millan-Gabet, Olivier Absil, Vanessa Bailey, Geoffrey Bryden, William Danchi, Grant Kennedy, Lindsay Marion, Aki Roberge, Eugene Serabyn, Andy Skemer, Karl Stapelfeldt, Alycia Weinberger, Mark Wyatt

Proceedings Volume 9907, 99070X (2016) https://doi.org/10.1117/12.2231839

KEYWORDS: Interferometry, Mid-IR, Stars, Calibration, Visibility, Telescopes, Sensors, Astronomy, Signal detection, Error analysis

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Proceedings Article | 16 September 2015 Paper

Exo-C: a probe-scale space observatory for direct imaging and spectroscopy of extrasolar planetary systems

Karl Stapelfeldt, Frank Dekens, Michael Brenner, Keith Warfield, Ruslan Belikov, Paul Brugarolas, Geoffrey Bryden, Kerri Cahoy, Supriya Chakrabarti, Serge Dubovitsky, Robert Effinger, Brian Hirsch, Andrew Kissil, John Krist, Jared Lang, Mark Marley, Michael McElwain, Victoria Meadows, Joel Nissen, Jeffrey Oseas, Chris Pong, Eugene Serabyn, Eric Sunada, John Trauger, Stephen Unwin

Proceedings Volume 9605, 96050T (2015) https://doi.org/10.1117/12.2191720

KEYWORDS: Planets, Coronagraphy, Telescopes, Space telescopes, Stars, Exoplanets, Wavefronts, Space operations, Imaging spectroscopy, Spectroscopy

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Proceedings Article | 28 August 2014 Paper

Exo-C: a probe-scale space mission to directly image and spectroscopically characterize exoplanetary systems using an internal coronagraph

Karl Stapelfeldt, Michael Brenner, Keith Warfield, Frank Dekens, Ruslan Belikov, Paul Brugarolas, Geoffrey Bryden, Kerri Cahoy, Supriya Chakrabarti, Serge Dubovitsky, Robert Effinger, Brian Hirsch, Andrew Kissil, John Krist, Jared Lang, Mark Marley, Michael McElwain, Victoria Meadows, Joel Nissen, Jeffrey Oseas, Eugene Serabyn, Eric Sunada, John Trauger, Stephen Unwin

Proceedings Volume 9143, 91432K (2014) https://doi.org/10.1117/12.2057115

KEYWORDS: Planets, Coronagraphy, Stars, Space telescopes, Telescopes, Space operations, Exoplanets, Wavefronts, Mirrors, Iterated function systems

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Proceedings Article | 24 July 2014 Paper

The LBTI hunt for observable signatures of terrestrial systems (HOSTS) survey: a key NASA science program on the road to exoplanet imaging missions

W. Danchi, V. Bailey, G. Bryden, D. Defrère, C. Haniff, P. Hinz, G. Kennedy, B. Mennesson, R. Millan-Gabet, G. Rieke, A. Roberge, E. Serabyn, A. Skemer, K. Stapelfeldt, A. Weinberger, M. Wyatt

Proceedings Volume 9146, 914607 (2014) https://doi.org/10.1117/12.2056681

KEYWORDS: Stars, Space telescopes, Planets, Solar system, Telescopes, Interferometers, Nulling interferometry, Imaging systems, Exoplanets, Sun

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Proceedings Article | 26 September 2013 Paper

The Debris Disk Explorer: a balloon-borne coronagraph for observing debris disks

Lewis Roberts, Geoffrey Bryden, Wesley Traub, Stephen Unwin, John Trauger, John Krist, Jack Aldrich, Paul Brugarolas, Karl Stapelfeldt, Mark Wyatt, David Stuchlik, James Lanzi

Proceedings Volume 8864, 88640A (2013) https://doi.org/10.1117/12.2025282

KEYWORDS: Stars, Coronagraphy, Telescopes, Planets, Mirrors, Wavefront sensors, Planetary systems, Solar system, Space telescopes, Light scattering

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Proceedings Article | 21 September 2012 Paper

Coronagraphic imaging of debris disks from a high altitude balloon platform

Stephen Unwin, Wesley Traub, Geoffrey Bryden, Paul Brugarolas, Pin Chen, Olivier Guyon, Lynn Hillenbrand, John Krist, Bruce Macintosh, Dimitri Mawet, Bertrand Mennesson, Dwight Moody, Lewis Roberts, Karl Stapelfeldt, David Stuchlik, John Trauger, Gautam Vasisht

Proceedings Volume 8442, 84420G (2012) https://doi.org/10.1117/12.924175

KEYWORDS: Coronagraphy, Telescopes, Stars, Planets, Space telescopes, Wavefronts, Sensors, Wavefront sensors, Planetary systems, Solar system

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Proceedings Article | 15 September 2011 Paper

Zodiac II: debris disk science from a balloon

Geoffrey Bryden, Wesley Traub, Lewis Roberts, Robin Bruno, Stephen Unwin, Stan Backovsky, Paul Brugarolas, Supriya Chakrabarti, Pin Chen, Lynne Hillenbrand, John Krist, Charles Lillie, Bruce Macintosh, Dimitri Mawet, Bertrand Mennesson, Dwight Moody, Zahidul Rahman, Justin Rey, Karl Stapelfeldt, David Stuchlik, John Trauger, Gautam Vaischt

Proceedings Volume 8151, 81511E (2011) https://doi.org/10.1117/12.899688

KEYWORDS: Telescopes, Stars, Coronagraphy, Space telescopes, Planets, Mirrors, Wavefronts, Signal to noise ratio, Deformable mirrors, Speckle

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