Results 51 to 60 of about 3,913,690 (210)

Beyond Accretion Limits: The Rise of Pulsating Gems

Astronomische Nachrichten, Volume 346, Issue 1, January 2025.
ABSTRACT The discovery of several ultraluminous X‐ray sources exhibiting fast and rapidly evolving X‐ray pulsations unequivocally associates these sources with accreting neutron stars orbiting relatively massive companion stars (> 8M ⊙$$ {}_{\odot } $$).
Gian Luca Israel, Roberta Amato, Matteo Imbrogno, Nicoló Oreste Pinciroli Vago, on behalf of a Larger Team, Guillermo Andres Rodríguez Castillo, Andrea Belfiore, Luigi Stella, Matteo Bachetti, Felix Fürst, Dom Walton, Matthew Middleton, Murray Brightman, Fabio Pintore, Ciro Pinto, Silvia Conforti, Luca Zampieri, Chiara Salvaggio, Anna Wolter, Andrea Tiengo, Andrea De Luca, Paolo Esposito, Ruben Salvaterra, Hannah Earnshaw, Tim Roberts, Andres Gúrpide, Sara Motta   +26 more
wiley   +1 more source

Physical Environment of Accreting Neutron Stars

Advances in Astronomy, Volume 2016, Issue 1, 2016., 2016
Neutron stars (NSs) powered by accretion, which are known as accretion‐powered NSs, always are located in binary systems and manifest themselves as X‐ray sources. Physical processes taking place during the accretion of material from their companions form a challenging and appealing topic, because of the strong magnetic field of NSs.
J. Wang, Elmetwally Elabbasy
wiley   +1 more source

A study of U Aquarii and the nucleosynthesis of neutrons and S-process elements in evolved stars of low mass [PDF]

, 2014
The origin of the extreme hydrogen deficiency observed in the R Coronae Borealis (RCrB) stars remains poorly understood. A likely mechanism for producing this deficiency is one whereby the original hydrogen envelope of the star is engulfed and ...
Malaney, Robert A.
core   +2 more sources

Identifying Red Supergiants in the Local Group Using JWST Photometry. I. NGC 6822, Sextans A, NGC 300, Wolf–Lundmark–Melotte, and IC 1613

The Astrophysical Journal
Red supergiants (RSGs) are crucial for studying the properties and evolution of massive stars. It is representative to conduct a census of RSGs across the Local Group, which spans a broad metallicity range.
Zhi-wen Li, Ming Yang, Biwei Jiang, Yi Ren   +3 more
doaj   +1 more source

A Study of Primordial Very Massive Star Evolution

The Astrophysical Journal, 2023
We present new evolutionary models of primordial very massive stars with initial masses ranging from 100 to 1000 M _⊙ that extend from the main sequence to the onset of dynamical instability caused by the creation of electron–positron pairs during core C,
Guglielmo Volpato, Paola Marigo, Guglielmo Costa, Alessandro Bressan, Michele Trabucchi, Léo Girardi   +5 more
doaj   +1 more source

Micritisation products in the inner ramp settings of the Abu Dhabi Lagoon

The Depositional Record, Volume 10, Issue 4, Page 402-425, September 2024.
Journey inside carbonate grains; internal microstructures of micritic envelopes and peloids in the Abu Dhabi lagoon. Abstract In numerous carbonate reservoirs in the Middle East, peloidal packstone‐grainstones are rock types with excellent pore storage potential in micritised microporous grains.
Thomas Teillet, Mohamed Harkat, Kai Hachmann, Elisa Garuglieri, Viswasanthi Chandra, Daniele Daffonchio, Mónica Sánchez‐Román, Volker Vahrenkamp   +7 more
wiley   +1 more source

SiO Masers in a Scutum Massive Star Cluster of Red Supergiants

The Astrophysical Journal, 2006
We have detected five objects toward a Scutum massive star cluster of red supergiants in the SiO J = 1-0, v = 1 or v = 2 transitions. The radial velocity data indicate that four of the detections are cluster members and that the other, which is located close to the X-ray source AX 1838-0655, is a foreground object.
Nakashima, JI, Deguchi, S
openaire   +3 more sources

IRC −10414: a bow-shock-producing red supergiant star★ [PDF]

Monthly Notices of the Royal Astronomical Society, 2013
Most runaway OB stars, like the majority of massive stars residing in their parent clusters, go through the red supergiant (RSG) phase during their lifetimes. Nonetheless, although many dozens of massive runaways were found to be associated with bow shocks, only two RSG bow-shock-producing stars, Betelgeuse and μCep, are known to date.
Gvaramadze, V. V., Menten, K. M., Kniazev, A. Y., Langer, N., Mackey, J., Kraus, A., Meyer, D. M. -A., Kaminski, T.   +7 more
openaire   +2 more sources

Physical properties of the first spectroscopically confirmed red supergiant stars in the Sculptor Group galaxy NGC 55 [PDF]

, 2017
We present K-band Multi-Object Spectrograph (KMOS) observations of 18 red supergiant (RSG) stars in the Sculptor Group galaxy NGC 55. Radial velocities are calculated and are shown to be in good agreement with previous estimates, confirming the ...
Kudritzki, R-P, Bergemann, M., C. J. Evans, Pietrzynski, G, R-P. Kudritzki, Evans, CJ, G. Pietrzyński, B. Davies, Turner, O, L. R. Patrick, Bergemann, M, Evans, C. J., O. Turner, Patrick, L. R., Pietrzyński, G., Davies, B., Patrick, LR, Turner, O., Ferguson, AMN, Ferguson, A. M. N., A. M. N. Ferguson, M. Bergemann, Davies, B, Kudritzki, R.-P.   +23 more
core   +1 more source

Photospheric Helium Abundance in Cool Giants: A Comprehensive Study

The Astrophysical Journal
High-resolution optical spectra of 16 red giants, two early asymptotic giant branch (AGB) stars, and two supergiants, having no/minimal - to super-lithium (Li)-rich abundances, are analyzed to investigate the helium (He)-enhancement. The spectra of eight
B. P. Hema, Gajendra Pandey
doaj   +1 more source