Results 91 to 100 of about 58,337 (174)

Precise Radial Velocities [PDF]

Annual Review of Astronomy and Astrophysics
Precise measurements of a star's radial velocity (RV) made using extremely stable, high-resolution, optical or near-infrared spectrographs can be used to determine the masses and orbital parameters of gravitationally bound extrasolar planets ...
Jennifer A. Burt, X. Dumusque, Sam Halverson   +2 more
semanticscholar   +1 more source

HET/HPF Observations of Helium in Warm, Hot, and Ultrahot Jupiters

The Astronomical Journal
The near-infrared helium triplet line is a powerful tool for studying atmospheric escape processes of close-in exoplanets, especially irradiated gas giants. Line profile fitting provides direct insight into the mechanisms driving atmospheric mass loss of
Jaume Orell-Miquel, Kyra Sampson, Caroline V. Morley, William D. Cochran, Girish M. Duvvuri, Daniel M. Krolikowski, Suvrath Mahadevan, Quang H. Tran   +7 more
doaj   +1 more source

Effects of Transient Stellar Emissions on Planetary Climates of Tidally Locked Exo-Earths

The Astronomical Journal
Space weather events in exoplanetary environments sourced from transient host star emissions, including stellar flares, coronal mass ejections, and stellar proton events, can substantially influence a planet's habitability and atmospheric evolution ...
Howard Chen, Paolo De Luca, Assaf Hochman, Thaddeus D. Komacek   +3 more
doaj   +1 more source

Time-resolved X-ray spectra of Proxima Centauri as seen by XMM-Newton

Astronomy & Astrophysics
Context. Stellar soft X-ray ([1, 100] Å) and extreme ultraviolet (also EUV, [100, 920] Å; jointly, XUV) radiation affect the evolution and chemistry of exoplanet atmospheres. It is, however, uncertain to what extent the radiation’s short-term variability
Damonte A., Pillitteri I., Maggio A., García Muñoz A., Micela G.   +4 more
doaj   +1 more source

Mapping Atmospheric Features of the Planetary-mass Brown Dwarf SIMP 0136 with JWST NIRISS

The Astrophysical Journal
In this paper, we analyze James Webb Space Telescope Near-Infrared Imager and Slitless Spectrograph time-series spectroscopy data to characterize the atmosphere of the planetary-mass brown dwarf SIMP J01365662+093347. Principal component analysis reveals
Roman Akhmetshyn, Étienne Artigau, Nicolas B. Cowan, Michael K. Plummer, Fei Wang, Ben Burningham, Björn Benneke, René Doyon, Ray Jayawardhana, David Lafrenière, Stanimir A. Metchev, Jason F. Rowe   +11 more
doaj   +1 more source

Is the Atmosphere of the Ultra-hot Jupiter WASP-121 b Variable?

The Astrophysical Journal Supplement Series
We present a comprehensive analysis of the Hubble Space Telescope observations of the atmosphere of WASP-121 b, an ultra-hot Jupiter. After reducing the transit, eclipse, and phase-curve observations with a uniform methodology and addressing the biases ...
Q. Changeat, J. W. Skinner, J. Y-K. Cho, J. Nättilä, I. P. Waldmann, A. F. Al-Refaie, A. Dyrek, B. Edwards, T. Mikal-Evans, M. Joshua, G. Morello, N. Skaf, A. Tsiaras, O. Venot, K. H. Yip   +14 more
doaj   +1 more source

Planet Earth in reflected and polarized light. I. Three-dimensional radiative transfer simulations of realistic surface-atmosphere systems

Astronomy & Astrophysics
Future ground- and space-based telescopes will enable the characterization of rocky exoplanets in reflected light, allowing for the observation of their albedo, which depends on surface, cloud, and atmospheric properties.
Giulia Roccetti, Claudia Emde, M. Sterzik, Mihail Manev, Julia V. Seidel, Stefano Bagnulo   +5 more
semanticscholar   +1 more source

Three Years of High-contrast Imaging of the PDS 70 b and c Exoplanets at Hα with MagAO-X: Evidence of Strong Protoplanet Hα Variability and Circumplanetary Dust

The Astronomical Journal
We present 3 yr of high-contrast imaging of the PDS 70 b and c accreting protoplanets with the new extreme AO system MagAO-X as part of the MaxProtoPlanetS survey of H α protoplanets.
Laird M. Close, Jared R. Males, Jialin Li, Sebastiaan Y. Haffert, Joseph D. Long, Alexander D. Hedglen, Alycia J. Weinberger, Katherine B. Follette, Daniel Apai, Rene Doyon, Warren Foster, Victor Gasho, Kyle Van Gorkom, Olivier Guyon, Maggie Y. Kautz, Jay Kueny, Jennifer Lumbres, Avalon McLeod, Eden McEwen, Clarissa Pavao, Logan Pearce, Laura Perez, Lauren Schatz, Judit Szulágyi, Kevin Wagner, Ya-Lin Wu   +25 more
doaj   +1 more source

The single beacon: progresses in understanding Earth as an exoplanet using DSCOVR/EPIC observations

Frontiers in Remote Sensing
Almost 6000 exoplanets have thus far been confirmed, revolutionizing our understanding of planetary habitability. Yet, despite the identification of Earth-like exoplanets, definitive evidence of extraterrestrial life remains elusive.
Xun Jian, Xun Jian, Lixiang Gu, Siteng Fan, Stuart J. Bartlett, Jiani Yang, Jonathan H. Jiang, Yangcheng Luo, Yuk L. Yung, Yuk L. Yung   +9 more
doaj   +1 more source

Planetary Rhythms: Synchronous Circulation on Variably Irradiated Asynchronous Planets

The Astrophysical Journal
Tidal locking of planets to their host stars results in an atmospheric circulation with a hotspot fixed to the frame of reference of the planet. On the other hand, asynchronously rotating planets feature moving hotspots either lagging or leading the ...
Deepayan Banik
doaj   +1 more source