Results 61 to 70 of about 22,040,331 (192)

Masks of strange dwarfs

, 2022
In 1995, Glendenning et al. postulated the existence of some exotic kinds of compact stars ressembling white dwarfs but containing a very dense core made of strange quark matter.
Perot, Loïc, Vallet, Pierre, Chamel, Nicolas   +2 more
core  

Physical Parameters and Properties of 20 Cold Brown Dwarfs in JWST

The Astrophysical Journal
We present a comprehensive analysis of 20 T and Y dwarfs using spectroscopy from the Near-Infrared Spectrograph (NIRSpec) CLEAR/PRISM and Mid-Infrared Instrument (MIRI) low-resolution spectrometer instruments on the James Webb Space Telescope.
Zhijun Tu, Shu Wang, Jifeng Liu
doaj   +1 more source

Disequilibrium Chemistry, Diabatic Thermal Structure, and Clouds in the Atmosphere of COCONUTS-2b

The Astronomical Journal
Located 10.888 pc from Earth, COCONUTS-2b is a planetary-mass companion to a young (150–800 Myr) M3 star, with a wide orbital separation (6471 au) and a low companion-to-host mass ratio (0.021 ± 0.005).
Zhoujian Zhang, Sagnick Mukherjee, Michael C. Liu, Jonathan J. Fortney, Emily Mader, William M. J. Best, Trent J. Dupuy, Sandy K. Leggett, Theodora Karalidi, Michael R. Line, Mark S. Marley, Caroline V. Morley, Mark W. Phillips, Robert J. Siverd, Joseph A. Zalesky   +14 more
doaj   +1 more source

GIANO Y -band spectroscopy of dwarf stars: Phosphorus, sulphur, and strontium abundances [PDF]

Astronomy & Astrophysics, 2015
In recent years a number of poorly studied chemical elements, such as phosphorus, sulphur, and strontium, have received special attention as important tracers of the Galactic chemical evolution. By exploiting the capabilities of the infrared echelle spectrograph GIANO mounted at the Telescopio Nazionale Galileo, we acquired high resolution spectra of ...
Caffau, E., Andrievsky, S., Korotin, S., Origlia, L., Oliva, E., Sanna, N., Ludwig, H.-G., Bonifacio, P.   +7 more
openaire   +4 more sources

A study of white dwarfs in the solar neighbourhood [PDF]

, 2003
The aim of this thesis is to revisit the properties of white dwarf stars in the Solar neighbourhood (distance > 100 pc), in particular their magnetic fields, the occurrence of binarity and their space density.
Kawka, Adela
core  

Structure and evolution of ultra-massive white dwarfs in general relativity [PDF]

, 2022
Context. Ultra-massive white dwarfs (M⋆ ≳ 1.05 M⊙) are of utmost importance in view of the role they play in type Ia supernovae explosions, merger events, the existence of high-magnetic -field white dwarfs, and the physical processes in the super ...
Santiago Torres, Roberto Raddi, Rebassa Mansergas, Alberto, Althaus, Leandro Gabriel, María E. Camisassa, Rebassa-Mansergas, A., Corsico, Alejandro Hugo, Tiara Battich, Torres, Santiago, Torres, Santiago Hernan, Alberto Rebassa-Mansergas, Battich, T., Althaus, L., Raddi, Roberto Ariel, Alejandro H. Córsico, Córsico, A., Raddi, R., Torres Gil, Santiago, Torres, S., Althaus, Leandro G., Raddi, Roberto, Leandro G. Althaus, Camisassa, María E., Camisassa, M., Córsico, Alejandro H., Rebassa-Mansergas, Alberto, Battich, Tiara, Camisassa, María Eugenia, Althaus, L. G., Camisassa, M. E., Corsico, A. H.   +30 more
core   +1 more source

Gamma rays from dark mediators in white dwarfs [PDF]

, 2018
[EN]We consider self-annihilation of dark matter, χ, into metastable mediators, Y, and their subsequent decay into photons inside white dwarfs. We focus on reactions of the type χχ→YY, where mediators, besides having a finite decay lifetime at rest ...
Cermeño Gavilán, Marina, Pérez García, María Ángeles   +1 more
core   +1 more source

Extending the Canada-France Brown Dwarf Survey to the near infrared

EPJ Web of Conferences, 2011
We present the first results of the Canada-France Brown Dwarfs Survey-InfraRed, hereafter CFBDSIR, our near infrared extension to the optical wide field survey CFBDS.
Bertin E., Willott C.J., Reylé C., Delfosse X., Artigau E., Forveille T., Delorme P., Albert L., Allard F.   +8 more
doaj   +1 more source

Multiple Stellar Populations at Less Evolved Stages. III. A Possible Helium Spread in NGC 2210

The Astrophysical Journal, 2023
Helium variations are common features of globular clusters (GCs) with multiple stellar populations. All the formation scenarios predict that secondary population stars are enhanced in helium, but the exact helium content depends on the polluters ...
Chengyuan Li, Xin Ji, Long Wang, Yue Wang, Baitian Tang, Antonino P. Milone, Yujiao Yang, Holger Baumgardt, Dengkai Jiang   +8 more
doaj   +1 more source

SPHEREx 0.75–5 μm Spectra for a Sequence of Nearby Brown Dwarfs

The Astrophysical Journal
The SPHEREx all-sky survey has now measured the R ∼ 40–100 infrared spectra of thousands of nearby brown dwarfs in the chemically rich 0.75–5 μ m range.
Zafar Rustamkulov, J. Davy Kirkpatrick, Rachel Akeson, Michael W. Werner, Matthew L. N. Ashby, Tzu-Ching Chang, Shuang-Shuang Chen, Asantha Cooray, Brendan P. Crill, Olivier Doré, C. Darren Dowell, Andreas L. Faisst, Howard Hui, Woong-Seob Jeong, Miju Kang, Phil M. Korngut, Carey M. Lisse, Daniel C. Masters, Gary J. Melnick, Chi H. Nguyen, Roberta Paladini, Volker Tolls, Yujin Yang, Michael Zemcov   +23 more
doaj   +1 more source