English
Related papers

Related papers: Older Ages for 23 Pre-Main Sequence Stars in Upper…

200 papers

The optical integrated spectra of three LMC young stellar clusters (NGC 1984, NGC 1994 and NGC 2011) exhibit concave continua and prominent molecular bands which deviate significantly from the predictions of single stellar population (SSP)…

Astrophysics of Galaxies · Physics 2017-08-30 Randa S. Asa'd , Alexandre Vazdekis , Miguel Cervino , Noelia E. D. Noel , Michael A. Beasley , Mahmoud Kassab

We review the current state of our knowledge concerning the rotation and angular momentum evolution of young stellar objects and brown dwarfs from a primarily observational view point. Periods are typically accurate to 1% and available for…

Astrophysics · Physics 2007-05-23 W. Herbst , J. Eisloeffel , R. Mundt , A. Scholz

We report the results of a study exploring the stellar populations of 13 luminous (L>L*), spectroscopically confirmed, galaxies in the redshift interval 5.5<z<6.5, all with WFC3/IR and IRAC imaging from the HST/CANDELS and Spitzer/SEDS…

Two eclipsing binaries in the USco association have recently yielded precise values of masses and radii for 4 low-mass members of the association. Standard evolution models would require these dM4.5 - dM5 stars to have ages which are…

Solar and Stellar Astrophysics · Physics 2017-01-11 James MacDonald , D. J. Mullan

We present SCExAO/CHARIS 1.1--2.4 micron integral field direct spectroscopy of the young HIP 79124 triple system. HIP 79124 is a member of the Scorpius-Centaurus association, consisting of an A0V primary with two low-mass companions at a…

In this third paper of a series on the precision of obtaining ages of stellar populations using the full spectrum fitting technique, we examine the precision of this technique in deriving possible age spreads within a star cluster. We test…

Astrophysics of Galaxies · Physics 2021-05-12 Randa Asa'd , Paul Goudfrooij , A. M. As'ad , H. G. El-Mir , L. Begum , A. Aljasmi , O. Almatroushi

In this paper we investigate the robustness of age measurements, age spreads, and stellar models in young pre-main sequence stars. For this effort, we study a young cluster, $\lambda$ Orionis, within the Orion star-forming complex. We use…

Solar and Stellar Astrophysics · Physics 2022-01-26 Lyra Cao , Marc H. Pinsonneault , Lynne A. Hillenbrand , Michael A. Kuhn

Blue straggler stars (BSS), one of the most massive members of star clusters, have been used for over a decade to investigate mass segregation and estimate the dynamical ages of globular clusters (GCs) and open clusters (OCs). This work is…

Astrophysics of Galaxies · Physics 2023-09-07 Khushboo K. Rao , Kaushar Vaidya , Manan Agarwal , Shanmugha Balan , Souradeep Bhattacharya

The frequency of discs around young stars, a key parameter for understanding planet formation, is most readily determined in young stellar clusters where many relatively coeval stars are located in close proximity. Observational studies…

Astrophysics of Galaxies · Physics 2015-06-22 Susanne Pfalzner , Manuel Steinhausen , Karl Menten

Asteroseismology provides powerful means to probe stellar interiors. The oscillations frequencies are closely related to stellar interior properties via the density and sound speed profiles. Since these are tightly linked with the mass and…

Astrophysics · Physics 2015-05-13 Yveline Lebreton , Josefina Montalban

We present a Bayesian implementation of isochrone fitting in deriving stellar ages and masses, incorporating absolute K magnitude ($\rm M_K$) derived from 2MASS photometry and Gaia DR1 parallax and differentiation between initial bulk…

Solar and Stellar Astrophysics · Physics 2018-03-30 Jane Lin , Aaron Dotter , Yuan-Sen Ting , Martin Asplund

Young stars form in associations, meaning that young stellar associations provide an ideal environment to measure the age of a nominally coeval population. Isochrone fitting, which is the typical method for measuring the age of a coeval…

Solar and Stellar Astrophysics · Physics 2024-05-09 Kendall Sullivan , Adam L. Kraus

We present a study of the evolution of the inner few astronomical units of protoplanetary disks around low-mass stars. We consider nearby stellar groups with ages spanning from 1 to 11 Myr, distributed into four age bins. Combining…

We have analysed K2 light curves for more than 3,000 low mass stars in the $\sim$8 Myr old Upper Sco association, the $\sim$125 Myr age Pleiades open cluster and the $\sim$700 Myr old Hyades and Praesepe open clusters to determine stellar…

Solar and Stellar Astrophysics · Physics 2018-11-28 John Stauffer , Luisa Rebull , Ann Marie Cody , Lynne Hillenbrand , Marc Pinsonneault , David Barrado , Jerome Bouvier , Trevor David

This overview summarizes the age dating methods available for young sub-solar mass stars. Pre-main sequence age diagnostics include the Hertzsprung-Russell (HR) diagram, spectroscopic surface gravity indicators, and lithium depletion;…

Astrophysics · Physics 2015-05-13 Lynne A. Hillenbrand

Aims. The main goal of this work is to date young open clusters using $\delta$ Sct stars. Seismic indices such as the large separation and the frequency at maximum power can help to constrain the models to better characterise the stars. We…

Solar and Stellar Astrophysics · Physics 2023-07-19 D. Pamos Ortega , G. M. Mirouh , A. García Hernández , J. C. Suárez Yanes , S. Barceló Forteza

The pre-main-sequence evolution of low-mass stars and brown dwarfs is studied numerically starting from the formation of a protostellar/proto-brown dwarf seed and taking into account the mass accretion onto the central object during the…

Solar and Stellar Astrophysics · Physics 2017-09-20 Eduard Vorobyov , Vardan Elbakyan , Takashi Hosokawa , Yuya Sakurai , Manuel Guedel , Harold Yorke

We investigate the distribution of bright main sequence stars near the northern edge of the M33 disk. Clustering on sub-kpc scales is seen among stars with ages near 10 Myr, and two large star-forming complexes are identified. Similar…

Astrophysics of Galaxies · Physics 2015-05-20 T. J. Davidge , T. H. Puzia , A. W. McConnachie

Context:Ages derived from the low mass stars still contracting onto the main sequence often differ from ages derived from the high mass ones that have already evolved away from it. Aims:We investigate the general claim of disagreement…

Astrophysics · Physics 2016-08-30 W. Lyra , A. Moitinho , N. van der Bliek , J. Alves

Over the last few years, many studies have found an empirical relationship between the abundance of a star and its age. Here we estimate spectroscopic stellar ages for 178 825 red-giant stars observed by the APOGEE survey with a median…