Zobrazeno 1 - 10
of 399
pro vyhledávání: '"RED-GIANT STARS"'
Publikováno v:
The Astrophysical Journal, Vol 977, Iss 2, p 138 (2024)
The magnetic dynamo mechanism of giant stars remains an open question, which can be explored by investigating their activity–rotation relations with multiple proxies. By using the data from the LAMOST and Galaxy Evolution Explorer surveys, we carri
Externí odkaz:
https://doaj.org/article/7d95153053b44e6fa739b57b170f6a48
Autor:
Mio Tomoyoshi, Kento Masuda, Teruyuki Hirano, Yui Kasagi, Hajime Kawahara, Takayuki Kotani, Tomoyuki Kudo, Motohide Tamura, Sébastien Vievard
Publikováno v:
The Astrophysical Journal, Vol 977, Iss 2, p 151 (2024)
In single-lined spectroscopic binaries (SB1s) where flux variations due to tidal deformation of the primary star (ellipsoidal variations, EVs) are detected, the binary mass can be determined by combining EVs with the primary's radial velocity (RV) va
Externí odkaz:
https://doaj.org/article/7c02c38c9cf347e4a11203b55b8354f9
Publikováno v:
The Astrophysical Journal, Vol 976, Iss 1, p 131 (2024)
Black hole (BH) demographics in different environments is critical in view of recent results on massive star binarity, and of the multimessenger detectability of compact object mergers. But the identification and characterization of noninteracting BH
Externí odkaz:
https://doaj.org/article/214dbc5158094c13a69ec13279485731
Publikováno v:
The Astrophysical Journal, Vol 974, Iss 2, p 181 (2024)
We investigate the absolute calibration of the tip of the red giant branch (TRGB) in the Small Magellanic Cloud (SMC) using small amplitude red giant stars (SARGs) classified by the Optical Gravitational Lensing Experiment (OGLE). We show that all st
Externí odkaz:
https://doaj.org/article/6c0b01dc7adf4e6f8b44e5bab986c881
Publikováno v:
The Astrophysical Journal, Vol 970, Iss 1, p 42 (2024)
Magnetic fields in the stellar interiors are key candidates to explain observed core rotation rates inside solar-like stars along their evolution. Recently, asteroseismic estimates of radial magnetic field amplitudes near the hydrogen-burning shell (
Externí odkaz:
https://doaj.org/article/19975c2c97604a109d3ba9aa8cc5ff06
Publikováno v:
The Astrophysical Journal, Vol 967, Iss 2, p 120 (2024)
We describe recent spectroscopic observations of red giant stars made by the Space Telescope Imaging Spectrograph (STIS) instrument on board the Hubble Space Telescope, which has provided spatially resolved observations of the warm chromospheric wind
Externí odkaz:
https://doaj.org/article/1b70352f458b498ca375683d83ad1e19
Autor:
J. M. Joel Ong, Marc Teng Yen Hon, Melinda Soares-Furtado, Alexander P. Stephan, Jennifer van Saders, Jamie Tayar, Benjamin Shappee, Daniel R. Hey, Lyra Cao, Mutlu Yıldız, Zeynep Çelik Orhan, Sibel Örtel, Benjamin Montet, Thomas W.-S. Holoien, Joss Bland-Hawthorn, Sven Buder, Gayandhi M. De Silva, Ken C. Freeman, Sarah L. Martell, Geraint F. Lewis, Sanjib Sharma, Dennis Stello
Publikováno v:
The Astrophysical Journal, Vol 966, Iss 1, p 42 (2024)
We report the discovery and characterization of TIC 350842552 (“Zvrk”), an apparently isolated, rapidly rotating ( P _rot ∼ 99 days) red giant observed by TESS in its southern Continuous Viewing Zone. The star’s fast surface rotation is indep
Externí odkaz:
https://doaj.org/article/bb5b471dee324e7eada5b0ab43f2da63
Publikováno v:
The Astrophysical Journal Supplement Series, Vol 272, Iss 1, p 2 (2024)
We present AspGap, a new approach to inferring stellar labels from the low-resolution Gaia XP spectra, including precise [ α /M] estimates—the first time these are obtained by such an approach. AspGap is a neural-network-based regression model tra
Externí odkaz:
https://doaj.org/article/9b576ab6d55b4fcf9e09d9c300f2ff52
Autor:
Maryum Sayeed, Melissa K. Ness, Benjamin T. Montet, Matteo Cantiello, Andrew R. Casey, Sven Buder, Megan Bedell, Katelyn Breivik, Brian D. Metzger, Sarah L. Martell, Leah McGee-Gold
Publikováno v:
The Astrophysical Journal, Vol 964, Iss 1, p 42 (2024)
Stellar models predict that lithium (Li) inside a star is destroyed during the first dredge-up phase, yet 1.2% of red giant stars are Li-rich. We aim to uncover possible origins of this population, by analyzing 1099 Li-rich giants ( A (Li) ≥ 1.5) i
Externí odkaz:
https://doaj.org/article/db2b991ad92147149b36f7258c61f787
Autor:
Jianzhao Zhou, Shaolan Bi, Jie Yu, Yaguang Li, Xianfei Zhang, Tanda Li, Liu Long, Mengjie Li, Tiancheng Sun, Lifei Ye
Publikováno v:
The Astrophysical Journal Supplement Series, Vol 271, Iss 1, p 17 (2024)
Based on all 2 minute cadence TESS light curves from Sector 1 to 60, we provide a catalog of 8651 solar-like oscillators, including frequency at maximum power ( ${\nu }_{\max }$ , with its median precision σ = 5.39%), large frequency separation (Δ
Externí odkaz:
https://doaj.org/article/d2f526a047dc439f9b1f1ae921bb40ad