Sciences and Exploration Directorate

Patricia T Boyd


Patricia T Boyd's Contact Card & Information.
Phone: 301.286.2550
Org Code: DA000
Mail Code 667
Greenbelt, MD 20771

Missions & Projects

Brief Bio

Padi Boyd is the Chief of the Exoplanets and Stellar Astrophysics Laboratory in the Astrophysics Science Division, and the Project Scientist for the Transiting Exoplanet Survey Satellite (TESS) Mission (a NASA Explorer Mission launched in 2018). She has been at Goddard since 1993, when she was a USRA visiting scientist with the High Speed Photometer and Polarimeter Team aboard the Hubble Space Telescope, studying the optical and ultraviolet polarization seen in X-ray binaries, pulsars and active galaxies.

In 1995, Boyd joined the Monitoring X-ray Experiment team, an X-ray all-sky monitor that was in development and testing as part of the Russian-led Spectrum X-Gamma mission. In 1997, she joined the Rossi X-ray Timing Experiment Guest Observer Facility performing science support for that mission. From 2003 to 2008, she managed that facility, as well as the Swift Science Center.

Padi spent a two-year detail at NASA Headquarters in Washington as the program scientist for the Kepler mission. While at NASA Headquarters, she was also the NASA point of contact for the MOST U.S. Guest Observer program and also served as a discipline scientist for X-ray and gamma-ray astronomy. She was also the Program Officer for the Origins of Solar Systems Exoplanets program.

Since returning to Goddard in 2010, she has held a number of positions including Deputy Project Scientist for Operations of the Hubble Space Telescope, Associate Chief of the Astroparticle Physics Laboratory, Acting Deputy Director of the Astrophysics Division, and Associate Director of the Astrophysics Division.

Her research interests focus on applying traditional and novel time series and spectral analysis techniques to uncover the drivers of stellar variability, and accretion in compact binaries and active galaxies, using data from a variety of space telescopes.

Research Interests

Long-term variability in X-ray binaries and accretion disk dynamics.

Astrophysics: X-ray Binaries & CVs

Multiwavelength studies of the flux and spectral variability of binaries harboring a compact object, on timescales much longer than the orbital period. Application of nonlinear time series analysis methods to X-ray light curves to uncover the drivers of accretion disk dynamics, and/or accretion rate changes.

Stellar Activity and the Star-Planet Connection

Astrophysics: Stars

Understanding the unique environments that stars of various ages and sizes can create for any extra-solar planets they may host requires research at the interfaces between heliophysics, planetary science, Earth science and astrophysics.

Investigating Variability Properties of Active Galaxies and Compact Binaries through Novel Time Series Analysis Techniques

Astrophysics: Active Galactic Nuclei (AGN)

From Phillipson, Boyd, Smale, Vogeley and McMillan (BAAS, 2019)

The light curves in multiple bandwidths of many black hole X-ray binaries (XRBs) and active galactic nuclei (AGN) are complex and resist traditional time series analysis techniques (Phillipson et al. 2018). Recurrence plots (RPs) and their quantitative analysis (RQA) were developed to study recurrences of dynamical trajectories in phase space. The structures present in RPs correlate to specific types of dynamical behavior in a system, including periodic, stochastic and chaotic motion, which are features of particular interest in the light curves of XRBs and AGN. The quantification of the structures in RPs has been applied to many fields, most recently in the characterization of stochastic behavior and nonlinear instabilities in the X-ray variability of microquasars, and the stability of orbits of terrestrial planets in the habitable zones of extrasolar systems. We apply the methods of RPs and their quantification to the three-year optical light curve of a Kepler AGN, which has been identified with a possible low-frequency quasi-periodic oscillation (Smith et al. 2018) corresponding to a temporal period of 44 days, and the X-ray light curves of four well-studied black hole XRBs from the RXTE, MAXI, and NuSTAR observatories. We provide evidence for traces of periodic, stochastic, and nonlinear, possibly chaotic, behavior in these light curves and compare to the results from our recent radiation-hydrodynamic simulations.

Current Projects

Rapidly rotating, X-ray bright stars and flare stars

KSwAGS- a Swift survey of the Kepler field of view to find previously unidentified active galaxies, CVs, X-ray binaries and unusual stars.

Anomalous low states in X-ray binaries and their effects on long-term cycles (LMC X-3, Her X-1).

X-ray Binaries & CVs


Associate Chief, Astroparticle Physics Laboratory and Deputy Project Scientist for Operations, Hubble Space Telescope

NASA - Goddard Space Flight Center

July 2011 - Present


B. S. in astronomy and astrophysics, Villanova University, Villanova, PA, 1987

M. S. in physics and atmospheric science, Drexel University, Philadelphia, PA, 1989

Ph. D. in physics and atmospheric science, Drexel University, Philadelphia, PA, 1993, thesis title: "Chaotic Scattering in the Gravitational Three-body Problem"

Selected Publications


2020. "The First Habitable-zone Earth-sized Planet from TESS. I. Validation of the TOI-700 System." The Astronomical Journal 160 (3): 116 [10.3847/1538-3881/aba4b2] [Journal Article/Letter]

2017. "Evidence for Binarity and Possible Disk Obscuration inKeplerObservations of the Pulsating RV Tau Variable DF Cygni." The Astrophysical Journal 839 (1): 48 [10.3847/1538-4357/aa67dd] [Journal Article/Letter]

2016. "Investigating the Long-term Variability of 4U1705-44; Evidence for an Underlying Nonlinear Double-Welled Oscillator." American Astronomical Society, HEAD meeting #15, id.120.32 15 120.32 [Full Text] [Journal Article/Letter]

2012. "Anomalous Low States and Long-term Variability in the Black Hole Binary LMC X-3." The Astrophysical Journal 756 146 [Full Text] [10.1088/0004-637X/756/2/146] [Journal Article/Letter]

2010. "Further calibration of the Swift ultraviolet/optical telescope." Monthly Notices of the Royal Astronomical Society 406 1687 [Full Text] [10.1111/j.1365-2966.2010.16832.x] [Journal Article/Letter]

2009. "The First Swift Ultraviolet/Optical Telescope GRB Afterglow Catalog." The Astrophysical Journal 690 163 [Full Text] [10.1088/0004-637X/690/1/163] [Journal Article/Letter]

2008. "AstroCappella: Songs of the Universe." BAAS 212 254 [Journal Article/Letter]

2008. "GRB 060607A: a gamma-ray burst with bright asynchronous early X-ray and optical emissions." Monthly Notices of the Royal Astronomical Society 385 453 [Full Text] [10.1111/j.1365-2966.2008.12859.x] [Journal Article/Letter]

2008. "Photometric calibration of the Swift ultraviolet/optical telescope." Monthly Notices of the Royal Astronomical Society 383 627 [Full Text] [10.1111/j.1365-2966.2007.12563.x] [Journal Article/Letter]

2007. "The exceptionally extended flaring activity in the X-ray afterglow of GRB 050730 observed with Swift and XMM-Newton." Astronomy and Astrophysics [10.1051/0004-6361:20066227] [Journal Article/Letter]

2007. "Optical, Infrared, and Ultraviolet Observations of the X-Ray Flash XRF 050416A." The Astronomical Journal 133 122 [Full Text] [10.1086/509656] [Journal Article/Letter]

2007. "Swift observations of GRB 050904: the most distant cosmic explosion ever observed." Astronomy and Astrophysics 462 73 [Full Text] [10.1051/0004-6361:20065173] [Journal Article/Letter]

2006. "Prompt Optical Observations of GRB 050319 with the Swift UVOT." The Astrophysical Journal 639 311 [Full Text] [10.1086/499293] [Journal Article/Letter]

2006. "Very Early Optical Afterglows of Gamma-Ray Bursts: Evidence for Relative Paucity of Detection." The Astrophysical Journal 652 1416 [Full Text] [10.1086/508481] [Journal Article/Letter]

2006. "Swift Panchromatic Observations of the Bright Gamma-Ray Burst GRB 050525a." The Astrophysical Journal 637 901 [Full Text] [10.1086/498425] [Journal Article/Letter]

2006. "Gamma-ray bursts: Huge explosion in the early Universe." Nature 440 164 [Full Text] [10.1038/440164a] [Journal Article/Letter]

2006. "The association of GRB 060218 with a supernova and the evolution of the shock wave." Nature 442 1008 [Full Text] [10.1038/nature04892] [Journal Article/Letter]

2005. "Swift UVOT Detection of GRB 050318." The Astrophysical Journal 635 1187 [Full Text] [10.1086/497627] [Journal Article/Letter]

2005. "Ultraviolet, Optical, and X-Ray Observations of the Type Ia Supernova 2005am with Swift." The Astrophysical Journal 635 1192 [Full Text] [10.1086/497437] [Journal Article/Letter]

2005. "Erratum: ``The Swift Gamma-Ray Burst Mission'' (ApJ, 611, 1005 [2004])." The Astrophysical Journal 621 558 [Full Text] [10.1086/427409] [Journal Article/Letter]

2004. "The Long-Term Light Curves of X-Ray Binaries Contain Simultaneous Periodic and Random Components." The Astrophysical Journal 612 1006 [Full Text] [10.1086/421078] [Journal Article/Letter]

2001. "X-Ray and Ultraviolet Orbital Phase Dependence in LMC X-3." The Astrophysical Journal 555 822 [Full Text] [10.1086/321511] [Journal Article/Letter]

2000. "Discovery of Millihertz ULTRAVIOLET Quasi-periodic Oscillations in Hercules X-1." The Astrophysical Journal 545 399 [Full Text] [10.1086/317786] [Journal Article/Letter]

2000. "Canonical Timing and Spectral Behavior of LMC X-3 in the Low/Hard State." The Astrophysical Journal 542 L127 [Full Text] [10.1086/312931] [Journal Article/Letter]


2018. "The Segmented Aperture Interferometric Nulling Testbed (SAINT) III: control systems analysis and preliminary results." Proc. SPIE, Space Telescopes and Instrumentation 2018: Optical, Infrared, and Millimeter Wave 10698 [10.1117/12.2318756] [Proceedings]

2018. "The WFIRST Exoplanet Microlensing Survey." arXiv e-prints arXiv:1803.08564 [Report]