Results 41 to 50 of about 11,425 (209)

Asteroseismology: Looking for Axions in the Red Supergiant Star Alpha Ori

The Astrophysical Journal, 2023
Abstract In this work, for the first time, we use seismic data as well as surface abundances to model the supergiant α-Ori, with the goal of setting an upper bound on the axion–photon coupling constant g a γ . We find that, in general, stellar models with g
Clara Severino, Ilídio Lopes
openaire   +3 more sources

A Tale of Two Impostors: SN2002kg and SN1954J in NGC 2403 [PDF]

, 2017
We describe new results on two supernova impostors in NGC 2403, SN 1954J(V12) and SN 2002kg(V37). For the famous object SN 1954J we combine four critical observations: its current SED, its Halpha emission line profile, the Ca II triplet in absorption in ...
Davidson, Kris, Gordon, Michael S., Humphreys, Roberta M., Van Dyk, Schuyler D.   +3 more
core   +3 more sources

Left Ringing: Betelgeuse Illuminates the Connection between Convective Outbursts, Mode Switching, and Mass Ejection in Red Supergiants

The Astrophysical Journal, 2023
Betelgeuse, the nearest red supergiant, dimmed to an unprecedented level in early 2020. The star emerged from this “Great Dimming” episode with its typical, roughly 400 days pulsation cycle halved, and a new dominant period of around 200 days.
Morgan MacLeod, Andrea Antoni, Caroline D. Huang, Andrea Dupree, Abraham Loeb   +4 more
doaj   +1 more source

The Isaac Newton Telescope Monitoring Survey of Local Group Dwarf Galaxies. V. The Star Formation History of Sagittarius Dwarf Irregular Galaxy Derived from Long-period Variable Stars

The Astrophysical Journal, 2023
We conducted an optical monitoring survey of the Sagittarius dwarf irregular galaxy (SagDIG) during the period of 2016 June–2017 October, using the 2.5 m Isaac Newton Telescopeat La Palama.
Tahere Parto, Shahrzad Dehghani, Atefeh Javadi, Elham Saremi, Jacco Th. van Loon, Habib G. Khosroshahi, Iain McDonald, Mohammad T. Mirtorabi, Mahdieh Navabi, Maryam Saberi   +9 more
doaj   +1 more source

What Physical Factors Influence the Transformation between Blue Supergiants and Red Supergiants?

The Astrophysical Journal
The post-main-sequence evolution of massive stars is highly sensitive to key stellar model parameters, particularly initial rotational velocity and metallicity.
Yun He, Hanfeng Song, Georges Meynet, Andre Maeder, Ruiyu Zhang, Ying Qin, Shitao Qi, Qingli Li, Qiong Zhan   +8 more
doaj   +1 more source

The young open cluster Berkeley 55 [PDF]

, 2011
We present UBV photometry of the highly reddened and poorly studied open cluster Berkeley 55, revealing an important population of B-type stars and several evolved stars of high luminosity.
Amparo Marco, Andrillat, Andrillat, Arellano Ferro, Caron, Draper, Díaz, Fitzgerald, Ginestet, González, Hassan, Howarth, Ignacio Negueruela, Jeffries, Koornneef, Levesque, Mermilliod, Mermilliod, Meynet, Mowlavi, Poelarends, Salasnich, Schmidt-Kaler, Shortridge, Skrutskie, Straižys, Turner, Valdes, Wegner, Weidemann, Winkler, Zhou   +31 more
core   +3 more sources

Undulating stratigraphy of a carbonate inner ramp lagoon and associated architectural facies heterogeneity: An example from the Late Jurassic Hanifa Formation, Central Saudi Arabia

Sedimentology, Volume 72, Issue 3, Page 734-762, April 2025.
Abstract This study offers new insights into the internal architecture of shallow marine carbonate sediments deposited in an epeiric sea formed on a broadly flooded passive margin continental shelf. The Ullayah Member of the Late Jurassic Hanifa Formation is exposed along the Tuwaiq Mountain Escarpment in Central Saudi Arabia and serves as an example ...
Pankaj Khanna, Ahmad R. Ramdani, Gaurav S. Gairola, Teyyuba Adigozalova, David Hodgetts, Volker C. Vahrenkamp   +5 more
wiley   +1 more source

Resolving stellar populations with integral field spectroscopy

Astronomische Nachrichten, Volume 340, Issue 9-10, Page 989-995, November‐December 2019., 2019
Abstract High‐performance instruments at large ground‐based telescopes have made integral field spectroscopy (IFS) a powerful tool for the study of extended objects such as galaxies, nebulae, or even larger survey fields on the sky. Here, we discuss the capabilities of IFS for the study of resolved stellar populations, using the new method of point ...
Martin M. Roth, Peter M. Weilbacher, Norberto Castro   +2 more
wiley   +1 more source

Critical Metallicity of Cool Supergiant Formation. II. Physical Origin

The Astrophysical Journal
This study investigates the physical origin of the critical metallicity required for the formation of cool supergiants, as revealed by stellar evolution models.
Po-Sheng Ou, Ke-Jung Chen
doaj   +1 more source

Red Supergiant Stars as Cosmic Abundance Probes: NLTE Effects in J-band Iron and Titanium Lines

, 2012
Detailed non-LTE calculations for red supergiant stars are presented to investigate the influence of NLTE on the formation of atomic iron and titanium lines in the J-band.
Allen, Barklem, Ben Davies, Bergemann, Bertrand Plez, Bresolin, Brooks, Brott, Butler, Garnett, Garnett, Gustafsson, Karin Lind, Kewley, Kudritzki, Kudritzki, Kupka, Lequeux, Lind, Maria Bergemann, Mashonkina, Piskunov, Plez, Plez, Ralchenko, Reetz, Rolf-Peter Kudritzki, Ryabchikova, Rybicki, Rybicki, Seaton, Skillman, Steenbock, Tremonti, Zach Gazak   +34 more
core   +3 more sources