Results 21 to 30 of about 451,529 (372)
EXPORT: Spectral classification and projected rotational velocities of Vega-type and pre-main sequence stars [PDF]
, 2001 In this paper we present the rst comprehensive results extracted from the spectroscopic campaigns car- ried out by the EXPORT (EXoPlanetary Observational Research Team) consortium.
A. Mora +21 more
semanticscholar +2 more sources
Hipparcos observations of pre-main-sequence stars
Monthly Notices of the Royal Astronomical Society, 1997 We present first results of Hipparcos observations of nearby low-mass pre-main-sequence (PMS) stars (T Tauri and Herbig Ae/Be stars). The data obtained by Hipparcos allow us to derive weighted mean parallaxes for three major nearby star-forming regions ...
R. Wichmann +4 more
semanticscholar +3 more sources
Evolution of X-Ray Activity in <25 Myr Old Pre-main Sequence Stars [PDF]
Astrophysical Journal, 2022 Measuring the evolution of X-ray emission from pre-main-sequence (PMS) stars gives insight into two issues: the response of magnetic dynamo processes to changes in the interior structure, and the effects of high-energy radiation on protoplanetary disks ...
K. Getman +6 more
semanticscholar +1 more source
X-Ray Superflares from Pre-main-sequence Stars: Flare Energetics and Frequency [PDF]
Astrophysical Journal, 2021 Solar-type stars exhibit their highest levels of magnetic activity during their early convective pre-main-sequence (PMS) phase of evolution. The most powerful PMS flares, superflares and megaflares, have peak X-ray luminosities of log(LX)=30.5–34.0 erg s−
K. Getman, E. Feigelson
semanticscholar +1 more source
X-Ray Superflares from Pre-main-sequence Stars: Flare Modeling [PDF]
Astrophysical Journal, 2021 Getman et al. report the discovery, energetics, frequencies, and effects on environs of >1000 X-ray superflares with X-ray energies E X ∼ 1034–1038 erg from pre-main-sequence (PMS) stars identified in the Chandra MYStIX and SFiNCs surveys.
K. Getman, E. Feigelson, G. Garmire
semanticscholar +1 more source
Untangling the Galaxy. III. Photometric Search for Pre-main-sequence Stars with Deep Learning [PDF]
Astronomical Journal, 2020 A reliable census of pre-main-sequence stars with known ages is critical to our understanding of early stellar evolution, but historically there has been difficulty in separating such stars from the field.
Aidan McBride +4 more
semanticscholar +1 more source
The Pre-main Sequence: Challenges and Prospects for Asteroseismology
Frontiers in Astronomy and Space Sciences, 2022 Stars do not simply pop up on the main sequence. Before the stars arrive on the zero-age main sequence, they form in the collapses of molecular clouds, gain matter through accretion processes, and compress their cores until hydrogen can burn in full ...
Konstanze Zwintz, Thomas Steindl
doaj +1 more source
Simulating the Sensitivity to Stellar Point Sources of Chandra X-Ray Observations
The Astrophysical Journal Supplement Series, 2023 The Chandra Cygnus OB2 Legacy Survey is a wide and deep X-ray survey of the nearby and massive Cygnus OB2 association. The survey has detected ∼8000 X-ray sources, the majority of which are pre-main-sequence X-ray-emitting young stars in the association ...
Nicholas J. Wright +4 more
doaj +1 more source
The Chandra Cygnus OB2 Legacy Survey: Design and X-Ray Point-source Catalog
The Astrophysical Journal Supplement Series, 2023 The Cygnus OB2 association is the largest concentration of young and massive stars within 2 kpc of the Sun, including an estimated ∼65 O-type stars and hundreds of OB stars.
Nicholas J. Wright +7 more
doaj +1 more source
The Astrophysical Journal Supplement Series, 2023 In our Galaxy, star formation occurs in a variety of environments, with a large fraction of stars formed in clusters hosting massive stars. OB stars have an important feedback on the evolution of protoplanetary disks orbiting around nearby young stars ...
M. G. Guarcello +12 more
doaj +1 more source