Zobrazeno 1 - 10
of 1 278
pro vyhledávání: '"late-type [Stars]"'
Autor:
Krisztián Vida, Zsolt Kővári, Martin Leitzinger, Petra Odert, Katalin Oláh, Bálint Seli, Levente Kriskovics, Robert Greimel, Anna Mária Görgei
Publikováno v:
Universe, Vol 10, Iss 8, p 313 (2024)
Flares, sometimes accompanied by coronal mass ejections (CMEs), are the result of sudden changes in the magnetic field of stars with high energy release through magnetic reconnection, which can be observed across a wide range of the electromagnetic s
Externí odkaz:
https://doaj.org/article/243f83c1fa4e4ce8a8d9cf2a91e663d8
Publikováno v:
The Astrophysical Journal, Vol 976, Iss 2, p 243 (2024)
Using the LAMOST DR7 low-resolution spectra, we carried out a systematic study of stellar chromospheric activity in both single and binary stars. We constructed a binary sample and a single-star sample, mainly using the binary belt and the main seque
Externí odkaz:
https://doaj.org/article/7225f7415ec642d7b9c37a00d4731abe
Autor:
Hu-Shan Xu, Li-Ying Zhu
Publikováno v:
The Astrophysical Journal, Vol 975, Iss 2, p 231 (2024)
Three sets of complete multicolor light curves of V694 Peg observed in 2013, 2015, and 2019 were presented and analyzed. Our photometric solutions show that this system was an A-type shallow contact binary in 2013 and 2015 while it converted to a W-t
Externí odkaz:
https://doaj.org/article/2d461c9075a444c7b4d4561650cdaa9e
Autor:
László Dobos, Alexander S. Szalay, Tamás Budavári, Evan N. Kirby, Robert H. Lupton, Rosemary F. G. Wyse
Publikováno v:
The Astronomical Journal, Vol 168, Iss 3, p 110 (2024)
Massively multiplexed spectrographs will soon gather large statistical samples of stellar spectra. The accurate estimation of uncertainties on derived parameters, such as the line-of-sight velocity v _los , especially for spectra with low signal-to-n
Externí odkaz:
https://doaj.org/article/0661ab7b5309400bb087d86a7a4aa480
Publikováno v:
The Astrophysical Journal Supplement Series, Vol 273, Iss 1, p 8 (2024)
Using the homogeneous X-ray catalog from ROSAT observations, we conducted a comprehensive investigation into stellar X-ray activity–rotation relations for both single and binary stars. Generally, the relation for single stars consists of two distin
Externí odkaz:
https://doaj.org/article/fcfc0a5dfdbd411599e9b5d76ca20de0
Autor:
Schuyler D. Van Dyk, Sundar Srinivasan, Jennifer E. Andrews, Monika Soraisam, Tamás Szalai, Steve B. Howell, Howard Isaacson, Thomas Matheson, Erik Petigura, Peter Scicluna, Andrew W. Stephens, Judah Van Zandt, WeiKang Zheng, Sang-Hyun Chun, Alexei V. Fillippenko
Publikováno v:
The Astrophysical Journal, Vol 968, Iss 1, p 27 (2024)
We follow our first paper with an analysis of the ensemble of the extensive preexplosion ground- and space-based infrared observations of the red supergiant (RSG) progenitor candidate for the nearby core-collapse supernova SN 2023ixf in Messier 101,
Externí odkaz:
https://doaj.org/article/df5de7b31d0a4c1cba8c04b95c7c70ee
Publikováno v:
The Astronomical Journal, Vol 167, Iss 6, p 291 (2024)
We present the first fluorine measurements in 12 normal K giants belonging to the Galactic thin and thick disks using spectra obtained with the Phoenix infrared spectrometer on the 2.1 m telescope at Kitt Peak. Abundances are determined from the (1
Externí odkaz:
https://doaj.org/article/66cd144adeae48e89dc33a300b908de2
Publikováno v:
The Astrophysical Journal, Vol 966, Iss 1, p 69 (2024)
M-type stars are crucial for stellar activity studies because they cover two types of magnetic dynamos and are particularly intriguing for habitability studies due to their abundance and long lifespans during the main-sequence stage. In this paper, w
Externí odkaz:
https://doaj.org/article/6f625ed930984712aab6b04abe0eb35c
Autor:
S. T. Douglas, P. A. Cargile, S. P. Matt, A. A. Breimann, J. A. Pérez Chávez, C. X. Huang, N. J. Wright, G. Zhou
Publikováno v:
The Astrophysical Journal, Vol 962, Iss 1, p 16 (2024)
The zero-age main sequence (ZAMS) is a critical phase for stellar angular momentum evolution, as stars transition from contraction-dominated spin-up to magnetic wind-dominated spin-down. We present the first robust observational constraints on rotati
Externí odkaz:
https://doaj.org/article/f116d8d95a034a5683f890e25c7a0e8d
Autor:
Alejandro Núñez, Marcel A. Agüeros, Jason L. Curtis, Kevin R. Covey, Stephanie T. Douglas, Sabine R. Chu, Stanislav DeLaurentiis, Minzhi (Luna) Wang, Jeremy J. Drake
Publikováno v:
The Astrophysical Journal, Vol 962, Iss 1, p 12 (2024)
Low-mass (≲1.2 M _⊙ ) main-sequence stars lose angular momentum over time, leading to a decrease in their magnetic activity. The details of this rotation–activity relation remain poorly understood, however. Using observations of members of the
Externí odkaz:
https://doaj.org/article/92ceda790eba4c13a4b1ba6152c5a793