Results 91 to 100 of about 995 (179)

The formation radius of HCN in O-rich asymptotic giant branch stars

Astronomy & Astrophysics
Context. Molecules detected in circumstellar envelopes around asymptotic giant branch (AGB) stars are generally well explained in terms of formation under chemical equilibrium in the stellar atmosphere or photochemistry in the outer expanding layers ...
Marinho L., Fonfría J. P., Agúndez M., Velilla-Prieto L., Quintana-Lacaci G., Cernicharo J.   +5 more
doaj   +1 more source

Mass Losing Asymptotic Giant Branch Stars And Supergiants

, 2016
This paper presents a summary of four invited and twelve contributed presentations on asymptotic giant branch stars and red supergiants, given over the course of two afternoon splinter sessions at the 19th Cool Stars Workshop. It highlights both recent observations and recent theory, with some emphasis on high spatial resolution, over a wide range of ...
Whitelock, Patricia A., Boyer, Martha, Höfner, Susanne, Wittkowski, Markus, Zijlstra, Albert A.   +4 more
openaire   +2 more sources

Li Evolution among Stars of Low/Intermediate Mass: the Metal-deficient Open Cluster NGC 2204

The Astronomical Journal
We have analyzed high-dispersion spectra in the Li 6708 Å region for 167 stars within the anticenter cluster NGC 2204. From 105 probable members, abundance analysis of 45 evolved stars produces [Fe/H] = −0.40 ± 0.12, [Si/Fe] = 0.14 ± 0.12, [Ca/Fe] = 0.29
Barbara J. Anthony-Twarog, Constantine P. Deliyannis, Aaron Steinhauer, Qinghui Sun, Bruce A. Twarog   +4 more
doaj   +1 more source

Phosphorus-bearing molecules PO and PN at the edge of the Galaxy. [PDF]

Nature, 2023
Koelemay LA, Gold KR, Ziurys LM.
europepmc   +1 more source

87th Annual Meeting of the Meteoritical Society 2025: Abstracts

Meteoritics &Planetary Science, Volume 60, Issue S1, Page 30-350, August 2025.
wiley   +1 more source

Discovery of a Metal-poor Red Giant Star with the Highest Ultralithium Enhancement

The Astrophysical Journal
We present the discovery of 2MASS J05241392−0336543 (hereafter J0524−0336), a very metal-poor ([Fe/H] = −2.43 ± 0.16), highly r -process-enhanced ([Eu/Fe] = +1.34 ± 0.10) Milky Way halo field red giant star, with an ultrahigh Li abundance of A (Li, 3D ...
Jeremy Kowkabany, Rana Ezzeddine, Corinne Charbonnel, Ian U. Roederer, Ella Xi Wang, Yangyang Li, Zoe Hackshaw, Timothy C. Beers, Anna Frebel, Terese T. Hansen, Erika Holmbeck, Vinicius M. Placco, Charli M. Sakari   +12 more
doaj   +1 more source

Ba Enrichment in Gaia MS+WD Binaries: Tracing s-process Element Production

The Astrophysical Journal Letters
A large population of intermediate-separation binaries, consisting of a main-sequence (MS) star and a white dwarf (WD), recently emerged from Gaia’s third data release (DR3), posing challenges to current models of binary evolution. Here we examine the s -
Param Rekhi, Sagi Ben-Ami, Na’ama Hallakoun, Sahar Shahaf, Silvia Toonen, Hans-Walter Rix   +5 more
doaj   +1 more source

A Planetary Nebula from a 5.7 M⊙ Progenitor in a 90 Myr M31 Star Cluster

The Astrophysical Journal Letters
Planetary nebulae (PNe) trace the late evolution of low-to-intermediate-mass stars, yet the masses of their progenitors are rarely measured directly. Here we present a PN physically associated with a young star cluster in M31, providing an unprecedented ...
Pinjian Chen, Bingqiu Chen, Xiaodian Chen, Shu Wang, Haibo Yuan   +4 more
doaj   +1 more source

Abundance of Ammonia in Carbon-rich Asymptotic Giant Branch Stars as Observed by Herschel/HIFI—A Rotational Diagram Approach

The Astrophysical Journal
The Herschel Heterodyne Instrument for the Far-Infrared (HIFI) obtained high-resolution spectroscopic observations of numerous Galactic and extragalactic sources, including 12 carbon-rich (C-rich) Galactic asymptotic giant branch (AGB) stars.
Ryszard Szczerba, Xiaohu Li, Juan Tuo, Mirosław R. Schmidt, Tom J. Millar, Gleb Fedoseev, Jixing Ge, Wasim Iqbal, Yong Zhang, Chuanlu Yang, Tao Yang, Xuan Fang, Cheng Zhu, Yihan Wu, Rong Ma, Xia Zhang, Xiaomin Song, Fangfang Li, Yuxuan Sun, Qixin Wu, Wenzhong Cai, Qing-Guo Sun, Yanan Feng, Jianchao Yang   +23 more
doaj   +1 more source

The Isaac Newton Telescope Monitoring Survey of Local Group Dwarf Galaxies. VII. Long-period Variable Stars in the Nearest Starburst Dwarf Galaxy, IC 10

The Astronomical Journal
To identify long-period variable (LPV) stars in IC 10—the nearest starburst galaxy of the Local Group—we conducted an optical monitoring survey using the 2.5 m Isaac Newton Telescope with the wide-field camera (WFC) in the i band and V band from 2015 to ...
Mahtab Gholami, Atefeh Javadi, Hamidreza Mahani, Jacco Th. van Loon, Habib Khosroshahi, Elham Saremi, Iain McDonald, Samaneh Eftekhari, Yi Ren, Hamed Altafi   +9 more
doaj   +1 more source