88 citations · 497 across the 31 of their papers we have counts for
31 papers
ESCAPE: a small explorer mission to study the stellar drivers of exoplanet evolution
Allison Youngblood, Kevin France, Brian Fleming +37
The long-term stability of exoplanetary atmospheres depends critically on the extreme-ultraviolet (EUV) photon and high-energy particle fluxes from the host star, which are poorly…
KRONOS II: Solar-like Umbra and Penumbra Properties on the Young Sun V1298~Tau
Matthew M. Murphy, Adina D. Feinstein, Meir E. Schochet +14
Transiting exoplanets provide a unique laboratory for studying stellar surface heterogeneities via starspot or facular occultations. When observed at multiple wavelengths, this con…
Investigating the High-energy Radiation Environment of Planets in Sun-like Binary Systems
Patrick R. Behr, Kevin France, Nicholas Kruczek +6
Far-ultraviolet (FUV) radiation is a driving source of photochemistry in planetary atmospheres. Proper interpretation of atmospheric observations requires a full understanding of t…
The MUSCLES Extension for Atmospheric Transmission Spectroscopy: Spectral energy distributions for 20 exoplanet host stars that JWST observed in Cycle 1
David J. Wilson, Allison Youngblood, Girish M. Duvvuri +11
Correctly interpreting JWST spectra of close-in exoplanets requires a measurement of the X-ray and ultraviolet light that the planets receive from their host stars. Here we provide…
The Advanced X-ray Imaging Satellite (AXIS) Community Science Book
Michael Koss, Nafisa Aftab, Steven W. Allen +395
The AXIS Community Science Book represents the collective effort of 592 scientists worldwide to define the transformative science enabled by the Advanced X-ray Imaging Satellite (A…
X-ray and UV Observations of the Young Sun HIP~67522: Evidence of Lyman-alpha Absorption Within the Planetary System
Cynthia S. Froning, Allison Youngblood, David J. Wilson +7
We present ultraviolet (UV) spectroscopy of the 17 Myr, G0V star, HIP 67522. The UV spectrum is characterized by strong chromospheric and transition region emission lines. There wa…
HWO Target Stars and Systems: A Survey of Archival UV and X-ray Data
Sarah Peacock, David J. Wilson, Tyler Richey-Yowell +14
We assess archival high-energy data for key stars on the Habitable Worlds Observatory (HWO) Target Stars and Systems 2025 list, as stellar radiation is critical to shaping and inte…
FUMES IV: Optical and Far-ultraviolet Spectra of a Flare on the M Dwarf GJ 4334
Girish M. Duvvuri, J. Sebastian Pineda, Aylin García Soto +5
On 2017-09-20 we observed GJ 4334, an M5V dwarf rotating with a period of 23.5 days, simultaneously with both the Space Telescope Imaging Spectrograph aboard Hubble (1160 -- 1710 A…
A Semi-Empirical Estimate of Solar EUV Evolution from 10 Myr to 10 Gyr
Kevin France, Girish Duvvuri, Cynthia Froning +9
The extreme-ultraviolet (EUV; 100 -- 911 Å) spectra of F, G, K, and M stars provide diagnostics of the stellar chromosphere through the corona, with line and continuum formation te…
Far-ultraviolet flares and variability of the young M dwarf AU Mic: a non-detection of planet c in transit at Lyman-alpha
Keighley E. Rockcliffe, Elisabeth R. Newton, Allison Youngblood +8
Atmospheric escape's potential to shape the exoplanet population motivates detailed observations of systems actively undergoing escape. AU Mic is a young and active M dwarf hosting…
Short-Term Balmer Line Emission Variability in M Dwarfs
Aylin Garcia Soto, Girish M. Duvvuri, Elisabeth R. Newton +3
M Dwarfs make up the majority of stars, offering an avenue for discovering exoplanets due to their smaller sizes. However, their magnetic activity poses challenges for exoplanet de…
The Mega-MUSCLES Treasury Survey: X-ray to infrared Spectral Energy Distributions of a representative sample of M dwarfs
David J. Wilson, Cynthia S. Froning, Girish M. Duvvuri +15
We present 5-1x10^7 Angstrom spectral energy distributions (SEDs) for twelve M dwarf stars covering spectral types M0-M8. Our SEDs are provided for community use as a sequel to the…
The Thermal Emission Spectrum of the Nearby Rocky Exoplanet LTT 1445A b from JWST MIRI/LRS
Patcharapol Wachiraphan, Zachory K. Berta-Thompson, Hannah Diamond-Lowe +7
The nearby transiting rocky exoplanet LTT 1445A b presents an ideal target for studying atmospheric retention in terrestrial planets orbiting M dwarfs. It is cooler than many rocky…
The Featherweight Giant: Unraveling the Atmosphere of a 17 Myr Planet with JWST
Pa Chia Thao, Andrew W. Mann, Adina D. Feinstein +29
The characterization of young planets (< 300 Myr) is pivotal for understanding planet formation and evolution. We present the 3-5m transmission spectrum of the 17 Myr, Jupiter-s…
Constraining atmospheric composition from the outflow: helium observations reveal the fundamental properties of two planets straddling the radius gap
Michael Zhang, Jacob L. Bean, David Wilson +13
TOI-836 is a ~2-3 Gyr K dwarf with an inner super Earth (, d) and an outer mini Neptune (, d). JWST/NIRSpec 2.8--5.2 m transmissi…
High-energy spectra of LTT 1445A and GJ 486 reveal flares and activity
H. Diamond-Lowe, G. W. King, A. Youngblood +19
The high-energy radiative output, from the X-ray to the ultraviolet, of exoplanet host stars drives photochemical reactions and mass loss in the upper regions of planetary atmosphe…
The dynamics of self-gravity wakes in the Mimas 5:3 bending wave: modifying the linear theory
Daniel D. Sega, Glen. Stewart, Josh E. Colwell +3
The satellite Mimas launches a bending wave -- a warping of the rings that propagates radially through self-gravity -- at the 5:3 inner vertical resonance with Saturn's rings. We p…
The life cycle of stars and their planets from the high energy perspective
Lia Corrales, Keivan G. Stassun, Tim Cunningham +19
One of the key research themes identified by the Astro2020 decadal survey is Worlds and Suns in Context. The Advanced X-ray Imaging Satellite (AXIS) is a proposed NASA APEX mission…
The High-Energy Spectrum of the Young Planet Host V1298 Tau
Girish M. Duvvuri, P. Wilson Cauley, Fernando Cruz Aguirre +4
V1298 Tau is a young pre-main sequence star hosting four known exoplanets that are prime targets for transmission spectroscopy with current-generation instruments. This work pieces…
The Variable Detection of Atmospheric Escape around the young, Hot Neptune AU Mic b
Keighley E. Rockcliffe, Elisabeth R. Newton, Allison Youngblood +5
Photoevaporation is a potential explanation for several features within exoplanet demographics. Atmospheric escape observed in young Neptune-sized exoplanets can provide insight in…
The MUSCLES Extension for Atmospheric and Transmission Spectroscopy: UV and X-ray Host-star Observations for JWST ERS & GTO Targets
Patrick R. Behr, Kevin France, Alexander Brown +8
X-ray through infrared spectral energy distributions (SEDs) are essential for understanding a star's effect on exoplanet atmospheric composition and evolution. We present a catalog…
Coronal X-Ray Emission from Nearby, Low-Mass, Exoplanet Host Stars Observed by the MUSCLES and Mega-MUSCLES HST Treasury Survey Projects
Alexander Brown, P. Christian Schneider, Kevin France +8
The high energy X-ray and ultraviolet (UV) radiation fields of exoplanet host stars play a crucial role in controlling the atmospheric conditions and the potential habitability of…
FUMES III: Ultraviolet and Optical Variability of M Dwarf Chromospheres
Girish M. Duvvuri, J. Sebastian Pineda, Zachory K. Berta-Thompson +2
We obtained ultraviolet and optical spectra for 9 M~dwarfs across a range of rotation periods to determine whether they showed stochastic intrinsic variability distinguishable from…
X-ray Emission from the Exoplanet Hosting LTT 1445 Triple Star System
Alexander Brown, Cynthia S. Froning, Allison Youngblood +5
JWST will be able to observe the atmospheres of rocky planets transiting nearby M dwarfs. The M dwarf triple star system LTT 1445, at a distance of 6.86 pc, hosts some of the neare…