Results 61 to 70 of about 560 (161)

Parallaxes, Proper Motions, and Near-infrared Photometry for 173 L and T Dwarfs from the US Naval Observatory Infrared Astrometry Program

The Astrophysical Journal
We present near-infrared parallax and proper motion astrometry for 74 L dwarfs and 99 T dwarfs, as single objects or in binary systems, obtained with the ASTROCAM astrometric imager on the USNO, Flagstaff Station 1.55 m telescope over two observing ...
Frederick J. Vrba, Adam C. Schneider, Jeffrey A. Munn, Arne A. Henden, Christain B. Luginbuhl, Conard C. Dahn, Harry H. Guetter, Blaise J. Canzian, Trudy M. Tilleman, Scott E. Dahm, Stephen J. Williams, Justice E. Bruursema, J. Davy Kirkpatrick, Adam J. Burgasser   +13 more
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Stellar Flare Study of nearby Young Moving Group Members with TESS Data

The Astrophysical Journal
We analyze TESS data to explore stellar flares and rotational characteristics in members of nearby young moving groups (NYMGs). Our study focuses on 417 members of NYMGs aged 10–150 Myr.
Andrew Tran, Inseok Song
doaj   +1 more source

Metal Pipe: A Broadly Applicable Stellar Abundance Pipeline Using Isochronal Parameters

The Astrophysical Journal
Characterizing exoplanet host stars at the population level requires a method of homogeneously characterizing stellar properties across all spectral types.
Jared R. Kolecki, Lauren M. Weiss
doaj   +1 more source

Stars on the ascending helium giant branch

Astronomy & Astrophysics
Hot subdwarf stars with masses above 0.8 M⊙ ascend the helium giant branch after the end of core helium burning, before entering the white dwarf cooling track or exploding as type Ib/c supernovae.
Pritzkuleit M., Dorsch M., Miller Bertolami M. M., Geier S., Bradshaw C. W., Dawson H.   +5 more
doaj   +1 more source

Chemical Fingerprints of M Dwarfs: High-resolution Spectroscopy on 31 M Dwarfs with SPIRou

The Astrophysical Journal
We extend the methodology introduced by F. Jahandar et al. to determine the effective temperature and chemical abundances of 31 slowly rotating solar neighborhood M dwarfs (M1–M5) using high-resolution spectra from CFHT/SPIRou.
Farbod Jahandar, René Doyon, Étienne Artigau, Neil J. Cook, Charles Cadieux, Jean-François Donati, Nicolas B. Cowan, Ryan Cloutier, Stefan Pelletier, Alan Alves-Brito, Jorge H. C. Martins, Hsien Shang, Andrés Carmona   +12 more
doaj   +1 more source

A Novel Survey for Young Substellar Objects with the W-band Filter. VII. Water-bearing Objects in the Core of the ρ Ophiuchi Cloud Complex

The Astrophysical Journal
We present a study of very low mass stars and brown dwarfs in the rich star-forming core of the ρ Ophiuchi cloud complex. The selection of the sample relies on detecting the inherent water absorption characteristic in young substellar objects.
Tanvi Sharma, Wen Ping Chen, Beth Biller, Loïc Albert, Belinda Damian, Jessy Jose, Bhavana Lalchand, Michael C. Liu, Yumiko Oasa   +8 more
doaj   +1 more source

Insight into the Formation of β Pic b through the Composition of Its Parent Protoplanetary Disk as Revealed by the β Pic Moving Group Member HD 181327

The Astronomical Journal
It has been suggested that β Pic b has a supersolar metallicity and subsolar C/O ratio. Assuming solar carbon and oxygen abundances for the star β Pic and therefore the planet’s parent protoplanetary disk, β Pic b’s C/O ratio suggests that it formed via ...
Henrique Reggiani, Jhon Yana Galarza, Kevin C. Schlaufman, David K. Sing, Brian F. Healy, Andrew McWilliam, Joshua D. Lothringer, Laurent Pueyo   +7 more
doaj   +1 more source

Competition between gravity waves excited by convection and tides in stars that host a companion

Astronomy & Astrophysics
Context. Asteroseismology has become a powerful diagnostic tool in stellar astrophysics, offering unprecedented insights into the internal structures and dynamics of stars.
Esseldeurs M., Ahuir J., Amard L., Mathis S., Decin L.   +4 more
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Tropical Cyclones on Tidally Locked Rocky Planets: Dependence on Rotation Period

The Astrophysical Journal
Tropical cyclones occur over the Earth’s tropical oceans, with characteristic genesis regions and tracks tied to the warm ocean surface that provide energy to sustain these storms.
Valeria Garcia, Cole M. Smith, Daniel R. Chavas, Thaddeus D. Komacek   +3 more
doaj   +1 more source

Potential Chromospheric Evaporation in the M Dwarf’s Flare Triggered by Einstein Probe Mission

The Astronomical Journal
Although flares from late-type main-sequence stars have been frequently detected in the multiwavelength, the associated dynamical process has been rarely reported so far.
J. Wang, X. Mao, C. Gao, H. Y. Liu, H. L. Li, H. W. Pan, C. Wu, Y. Liu, G. W. Li, L. P. Xin, S. Jin, D. W. Xu, E. W. Liang, W. M. Yuan, J. Y. Wei   +14 more
doaj   +1 more source