Results 31 to 40 of about 1,023 (124)

Radii of 88 M subdwarfs and updated radius relations for low-metallicity M-dwarf stars [PDF]

, 2019
M subdwarfs are low-metallicity M dwarfs that typically inhabit the halo population of the Galaxy. Metallicity controls the opacity of stellar atmospheres; in metal-poor stars, hydrostatic equilibrium is reached at a smaller radius, leading to smaller ...
Veyette, Mark, Henderson, Calen B., Davy Kirkpatrick, J., Calchi-Novati, Sebastiano, Penny, Matthew T., Cushing, Michael C., Shvartzvald, Y., Scott Gaudi, B., Fajardo-Acosta, Sergio B., Boeshaar, Patricia C., Muirhead, Philip S., Kesseli, Aurora Y.   +11 more
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A transit survey to search for planets around hot subdwarfs

, 2021
In this presentation I give an insight of my PhD project dedicated to the search for exoplanets around hot subdwarf stars (sdO/B). I use data from the missions Kepler, K2, TESS and CHEOPS, in order to detect transits of close bodies down to the size of ...
Valérie Van Grootel, Martín Dévora-Pajares, Francisco Pozuelos, Stephane Charpinet, Antoine Thuillier   +4 more
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TiH IN SUBDWARFS

, 2005
Author Institution: Department of Chemistry, University of Waterloo, Waterloo, Ont., Canada N2L 3G1; NASA Ames Research Center, Mailstop 230-3, Moffett Field, CA; 94035; National Solar Observatory, 950 N. Cherry Ave., P.O.
Milsom, J. A., Dulick, M., Bauschlicher, Charles W., Jr., Ram, R. S., Bernath, P. F., Burrows, A., Sharp, C. M.   +6 more
core   +1 more source

Detection of hot subdwarf binaries and He-poor hot subdwarf stars using machine learning methods and a large sample of Gaia XP spectra

Astronomy & Astrophysics
Context. Hot subdwarfs (hot sds) are compact evolved stars near the extreme horizontal branch, and they are key to understanding stellar evolution and the UV excess in galaxies.
Ambrosch M., Viscasillas Vázquez C., Solano E., Ulla A., Pérez-Couto X., Pérez-Fernández E., Medžiūnas A., Manteiga M., Dafonte C., Drazdauskas A., Magrini L., Mikolaitis Š., Šatas V.   +12 more
doaj   +1 more source

Investigation of the Nature of the B[e] Star CI Cam in the Optical Range

Galaxies
The B[e] phenomenon is observed in a wide range of stars at various evolutionary stages. Its nature remains uncertain. The B[e] phenomenon is defined as the simultaneous presence of low-excitation forbidden line emission and strong infrared excess in the
Elena A. Barsukova, Vitaly P. Goranskij, Aleksandr N. Burenkov, Ilya A. Yakunin   +3 more
doaj   +1 more source

A Universal Transition in Atmospheric Diffusion for Hot Subdwarfs Near 18,000 K [PDF]

, 2017
In the color-magnitude diagrams of globular clusters, when the locus of stars on the horizontal branch extends to hot temperatures, discontinuities are observed at colors corresponding to ∼12,000 and ∼18,000 K.
E. Dalessandro, A. V. Sweigart, Salaris, M., Taylor, J. M., L. R. Bedin, Brown, T. M., CASSISI, Santi, Renzini, A., Dalessandro, Emanuele, Salaris, M, J. M. Taylor, Taylor, JM, Renzini, A, A. Renzini, Dalessandro, E, M. Salaris, Sweigart, A. V., Sweigart, AV, T. M. Brown, BEDIN, Luigi, Bellini, A., S. Cassisi, Brown, TM, Cassisi, S, Bellini, A, Bedin, LR, A. Bellini   +26 more
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Ultra-cool Subdwarfs in the Subaru HSC survey

, 2018
Ultra-cool subdwarfs (UCSD) are metal-poor low-mass stars and brown dwarfs with spectral types of M, L, T, and Y. Their old ages and long lives make them effective tracers to study the history of star formation and chemical enrichment in Milky Way.
Lee, Chien-Hsiu (5595644), Magnier, Eugene, Chen, Wen-Ping (5595650), Chiang, Poshih (5595641), Lee, Chien-Hsiu, Magnier, Eugene (5595647), Chiang, Poshih, Chen, Wen-Ping   +7 more
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Shaping the horizontal branch: The role of envelope mass in the evolution of stripped core-helium-burning stars

Astronomy & Astrophysics
The location of a star along the horizontal branch (HB) during core-helium burning is primarily determined by the amount of mass lost by its progenitor.
Arancibia Rojas E., Zorotovic M., Vučković M., Bobrick A., Durán-Reyes A.   +4 more
doaj   +1 more source

New ultracool subdwarfs identified in large-scale surveys using Virtual Observatory tools

, 2017
Aims. We aim to develop an efficient method to search for late-type subdwarfs (metal-depleted dwarfs with spectral types ≥M5) to improve the current statistics.
M. R. Zapatero Osorio, M. Espinoza Contreras, M. Aberasturi, C. Rodrigo, E. Solano, E. L. Martín, N. Lodieu   +6 more
core   +1 more source

Exploring Late Stellar Evolution in the Era of Large Surveys: Machine Learning Prospects for Hot Subdwarfs and White Dwarfs

Universe
The rapid growth of large-scale astronomical surveys and advances in data-driven analysis techniques have transformed the study of late-stage stellar evolution.
Princy Ranaivomanana, Murat Uzundag
doaj   +1 more source