Results 21 to 30 of about 4,354 (212)

An 18.9 min blue large-amplitude pulsator crossing the ‘Hertzsprung gap’ of hot subdwarfs [PDF]

Nature Astronomy, 2022
Blue large-amplitude pulsators (BLAPs) represent a mysterious class of hot stars pulsating in an unexpectedly extreme way. Here we report the discovery of an unusual BLAP at a short-lived phase that provides a new path to understand their physical ...
Jie Lin, Chengyuan Wu, Xiaofeng Wang, P. Németh, H. Xiong, Tao Wu, A. Filippenko, Yongzhi Cai, T. Brink, Shengyu Yan, Xiangyun Zeng, Yangping Luo, D. Xiang, Jujia Zhang, Weikang Zheng, Yi Yang, J. Mo, G. Xi, Jicheng Zhang, A. Iskandar, A. Esamdin, Xiaojun Jiang, H. Sai, Zi-Jiao Wei, Liyang Chen, Fangzhou Guo, Zhihao Chen, Wenxiong Li, Weili Lin, Han Lin, Xinghan Zhang   +30 more
semanticscholar   +1 more source

New Candidate Extreme T Subdwarfs from the Backyard Worlds: Planet 9 Citizen Science Project [PDF]

Astrophysical Journal, 2021
Schneider et al. presented the discovery of WISEA J041451.67−585456.7 and WISEA J181006.18−101000.5, which appear to be the first examples of extreme T-type subdwarfs (esdTs; metallicity ≤−1 dex, T eff ≲ 1400 K).
A. Meisner, A. Schneider, A. Burgasser, F. Marocco, M. Line, J. Faherty, J. Kirkpatrick, D. Caselden, M. Kuchner, C. Gelino, J. Gagné, C. Theissen, Roman Gerasimov, C. Aganze, Chih-Chun Hsu, J. Wisniewski, S. Casewell, D. B. Gagliuffi, S. Logsdon, P. Eisenhardt, K. Allers, J. Debes, Michaela B. Allen, Nikolaj Stevnbak Andersen, S. Goodman, Léopold Gramaize, David W. Martin, Arttu Sainio, M. Cushing, T. B. W. P. 9. Collaboration   +29 more
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A Grid of Synthetic Spectra for Subdwarfs: Non-LTE Line-blanketed Atmosphere Models [PDF]

Astrophysical Journal Supplement Series, 2021
A new grid of detailed atmosphere model spectra for hot and moderately cool subdwarf stars is presented. High-resolution spectra and synthetic photometry are calculated in the range from 1000–10,000 Å using non-LTE fully line-blanketed atmosphere ...
T. A. Pacheco, M. Diaz, R. Levenhagen, P. Coelho   +3 more
semanticscholar   +1 more source

Hot subdwarfs from the surviving companions of the white dwarf + main-sequence channel of Type Ia supernovae [PDF]

, 2021
Some surviving companions of type Ia supernovae (SNe Ia) from the white-dwarf + main-sequence (WD + MS) channel may evolve to hot subdwarfs. In this paper, we preformed stellar evolution calculations for surviving companions of close WD +MS systems in ...
Xiangcun Meng, Yang Luo
semanticscholar   +1 more source

Wide companions to M and L subdwarfs with Gaia and the Virtual Observatory [PDF]

Astronomy & Astrophysics, 2021
Aims. The aim of the project is to identify wide common proper motion companions to a sample of spectroscopically confirmed M and L metal-poor dwarfs (also known as subdwarfs) to investigate the impact of metallicity on the binary fraction of low-mass ...
J. Gonz'alez-Payo, M. Cort'es-Contreras, N. Lodieu, E. Solano, Z. Zhang, M. G'alvez-Ortiz   +5 more
semanticscholar   +1 more source

A transit survey to search for planets around hot subdwarfs

Bulletin de la Société royale des sciences de Liège, 2023
Hot subdwarf stars are small post-red-giant-branch stars. To this day, no planets have been confirmed around them. In this document we present the first results of our analysis to quantify the presence of planets around hot subdwarfs by performing a wide
A. Thuillier, V. Grootel, F. Pozuelos, M. Dévora-Pajares, S. Charpinet, Lionel Siess   +5 more
semanticscholar   +1 more source

Phases of Mass Transfer from Hot Subdwarfs to White Dwarf Companions and Their Photometric Properties [PDF]

Astrophysical Journal, 2021
Binary systems of a hot subdwarf B (sdB) star + a white dwarf (WD) with orbital periods less than 2–3 hr can come into contact due to gravitational waves and transfer mass from the sdB star to the WD before the sdB star ceases nuclear burning and ...
E. Bauer, T. Kupfer
semanticscholar   +1 more source

WISEA J041451.67–585456.7 and WISEA J181006.18–101000.5: The First Extreme T-type Subdwarfs? [PDF]

Astrophysical Journal, 2020
We present the discoveries of WISEA J041451.67−585456.7 and WISEA J181006.18−101000.5, two low-temperature (1200–1400 K), high proper motion T-type subdwarfs. Both objects were discovered via their high proper motion (>0.″5 yr−1); WISEA J181006.18−101000.
A. Schneider, A. Burgasser, Roman Gerasimov, F. Marocco, J. Gagné, S. Goodman, Paul-André Beaulieu, William Pendrill, Austin Rothermich, Arttu Sainio, M. Kuchner, D. Caselden, A. Meisner, J. Faherty, E. Mamajek, Chih-Chun Hsu, J. Greco, M. Cushing, J. Kirkpatrick, Daniella C. Bardalez-Gagliuffi, S. Logsdon, K. Allers, J. Debes   +22 more
semanticscholar   +1 more source

Post-merger evolution of double helium white dwarfs and distribution of helium-rich hot subdwarfs [PDF]

, 2021
The mergers of double helium white dwarfs are believed to form isolated helium-rich hot subdwarfs. Observation shows that the helium-rich hot subdwarfs can be divided into two subgroups based on whether the surface is carbonrich or carbon-normal.
Jinlong Yu, Xianfei Zhang, G. Lü
semanticscholar   +1 more source

A Robust Identification Method for Hot Subdwarfs Based on Deep Learning

Astrophysical Journal Supplement Series, 2022
Hot subdwarf stars are a particular type of star that is crucial for studying binary evolution and atmospheric diffusion processes. In recent years, identifying hot subdwarfs by machine-learning methods has become a hot topic, but there are still ...
Lei Tan, Y. Mei, Zhicun Liu, Ya Luo, H. Deng, Feng Wang, LinHua Deng, Chaoyang Liu   +7 more
semanticscholar   +1 more source