• Research Astrophysicist

    I am a Research Astrophysicist at the NASA Goddard Space Flight Center in Greenbelt, MD. I work in the Exoplanets and Stellar Astrophysics Laboratory on stellar magnetic activity and its effects on exoplanets, and I help develop new UV missions.

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  • Research

    Hubble observes a lunar eclipse

    I led Hubble's first observation of a lunar eclipse, which was also the first observation of a lunar eclipse at UV wavelengths. Using the moon as a mirror, this allowed us to see the Earth transiting the Sun as if it were a transiting exoplanet. We detected ozone and Rayleigh scattering. See the paper or this video from NASA for more details.

    M dwarf Lyman alpha spectroscopy

    H I Lyman alpha (121.6 nm) is the brightest UV emission line in an M dwarf. It's also the hardest to observe because of severe interstellar H I attenuation and bright airglow from Earth's upper atmosphere. I work on various projects related to correcting for the ISM attenuation in Hubble STIS spectra, removing airglow from Hubble COS spectra, uncovering the intrinsic line core and wing shapes, and estimating this important emission line from more accessible observables.

    EUV emission, CMEs, and Exoplanets

    Low-mass stars, especially M dwarfs, are known to emit strongly in the X-ray/UV and flare very frequently, especially during their long youths (~1 billion years compared to the Sun's ~100 million year long pre-main sequence period). While we can detect photons from many parsecs away, detecting signatures of energetic particles or coronal mass ejections (CMEs) is not easy. The ESCAPE SMEX concept can help by measuring coronal dimming.

    Mega-MUSCLES Hubble Space Telescope Treasury Survey

    As a graduate student at the University of Colorado, I was part of the MUSCLES Treasury Survey team to construct complete spectral energy distributions (SEDs) of K and M dwarf stars with exoplanets. Now, I'm a Co-I of the ongoing Mega-MUSCLES Treasury Survey, which is observing more stars and pushing to later type M dwarfs. For more details on these projects, visit the MUSCLES website and download our spectral energy distributions from MAST. See also the FUMES survey, which is focused on younger M dwarfs.

    Orion Nebula BN/KL Outflow

    This image from Gemini South shows the spectacular 500-year-old explosion triggered (possibly) by a merger of two massive protostars (Bally et al. 2015; gold = H2, blue = Fe II). This explosion, also called the BN/KL outflow, is located several arcminutes north of the Trapezium cluster in the Orion Nebula. Using the near-infrared TripleSpec spectrograph at Apache Point Observatory, I spectrally mapped the outflow to make spatially resolved temperature and density maps of this beautiful outflow.


    You can find a list of my publications and conference abstracts at the Astrophysics Data System and ResearchGate.