Results 61 to 70 of about 14,196,004 (190)

Pre-main-sequence variability across the radiative-convective gap [PDF]

, 2009
We use I-band imaging to perform a variability survey of the 13-Myr-old cluster h Per. We find a significant fraction of the cluster members to be variable. Most importantly, we find that variable members lie almost entirely on the convective side of the
Nathan J. Mayne (21287030), S.P. Littlefair (7580111), Eric S. Saunders (21824861), Tim Naylor (21824576)   +3 more
core   +4 more sources

Two Young Eclipsing Binaries in Orion with Temperatures and Radii Affected by Spots and Third Bodies

The Astronomical Journal
In this work we present a model of two young eclipsing binaries in the Orion complex. Both heavily spotted, they present radii and temperatures that are in disagreement with the predictions of standard stellar models.
Marina Kounkel, Keivan G. Stassun
doaj   +1 more source

The Pre--Main-Sequence of A-type stars

, 2004
Young A-type stars in the pre--main-sequence (PMS) evolutionary phase are particularly interesting objects since they cover the mass range (1.5-4 solar ma sses) which is most sensitive to the internal conditions inherited during the protostellar phase. In particular, they undergo a process of thermal relaxation from which they emerge as fully radiative
Marconi, Marcella, Palla, Francesco
openaire   +2 more sources

Theory and evidence of global Rossby waves in upper main-sequence stars: r-mode oscillations in many Kepler stars [PDF]

, 2017
Asteroseismic inference from pressure modes (p modes) and buoyancy, or gravity, modes (g modes) is ubiquitous for stars across the Hertzsprung–Russell diagram. Until now, however, discussion of r modes (global Rossby waves) has been rare.
Lee, Umin, Hideyuki Saio, Kurtz, Donald Wayne, Antoci, Victoria L, Victoria L Antoci, Murphy, Simon J, Simon J Murphy, Kurtz, Donald W., Murphy, Simon J., Saio, Hideyuki, Donald W Kurtz, Antoci, Victoria L., Umin Lee   +12 more
core   +1 more source

The Nature of X-Rays from Young Stellar Objects in the Orion Nebula Cluster—A Chandra HETGS Legacy Project

The Astrophysical Journal
The Orion Nebula Cluster (ONC) is the closest site of very young (∼1 Myr) massive star formation The ONC hosts more than 1600 young and X-ray bright stars with masses ranging from ∼0.1–35 M _⊙ .
Norbert S. Schulz, David P. Huenemoerder, David A. Principe, Marc Gagne, Hans Moritz Günther, Joel Kastner, Joy Nichols, Andrew Pollock, Thomas Preibisch, Paola Testa, Fabio Reale, Fabio Favata, Claude R. Canizares   +12 more
doaj   +1 more source

Modelling δ Scuti pulsations: a new grid of p, g, and f modes across pre-main-sequence to post-main-sequence evolution

Space-based photometry reveals regular high-frequency patterns in many young Scuti stars. These pulsations provide a powerful means of inferring stellar properties, particularly ages, for young Scuti stars for which traditional age-dating methods are ...
Murphy, Simon J., Bedding, Timothy R., Gautam, Anuj   +2 more
core   +1 more source

Instability strip for pre-main-sequence stars [PDF]

, 2006
peer reviewedWe apply the Time Dependent Convection (TDC) treatment presented in Grigahcene et al. (2005) to the study of Pre-main sequence pulsating stars. The stabilization of the p-modes at the red edge of the Instability Strip (IS) is obtained by our
Dupret, Marc-Antoine, Grigahcene, A., Scuflaire, Richard, Garrido, R., Gabriel, Maurice   +4 more
core   +1 more source

Characterizing the Low-mass Pre-main-sequence Population in the Low-metallicity Star-forming Region Dolidze 25 Using VLT-MUSE

The Astrophysical Journal
The metallicity of the star-forming environment is a fundamental parameter shaping the evolution of protoplanetary disks and the formation of planetary systems, yet its influence remains poorly constrained.
Mizna Ashraf, Jessy Jose, Gregory J. Herczeg, Min Fang, Varsha Ramachandran, Carlo F. Manara, Christian Schneider, Megan Reiter, Kiran Kumar Sunil   +8 more
doaj   +1 more source

Spectral Variability of Herbig Ae Star V1295, Aquila

Galaxies
This article presents the results of long-term spectral studies of the unusual Herbig Ae star V1295 Aql. The variability in the spectrophotometric parameters of the emission and absorption components of the hydrogen lines Hα, Hβ, and D Na I—and of ...
Hemayil Adigozalzade, Silva Jarvinen, Swetlana Hubrig, Ulviyya Bashirova, Nariman Ismailov   +4 more
doaj   +1 more source

X-Ray Evolution of Young Stars: Early Dimming and Coronal Softening in Solar-mass Stars with Implications for Planetary Atmospheres

The Astrophysical Journal
X-ray and ultraviolet (XUV) emission from young stars plays a critical role in shaping the evolution of planetary atmospheres and the conditions for habitability.
Konstantin V. Getman, Eric D. Feigelson, Vladimir S. Airapetian, Gordon P. Garmire   +3 more
doaj   +1 more source