Results 21 to 30 of about 2,436 (245)

Exploring the Extremes: Characterizing a New Population of Old and Cold Brown Dwarfs

The Astronomical Journal, 2023
Mapping out the populations of thick disk and halo brown dwarfs is important for understanding the metallicity dependence of low-temperature atmospheres and the substellar mass function.
Aaron M. Meisner, S. K. Leggett, Sarah E. Logsdon, Adam C. Schneider, Pascal Tremblin, Mark Phillips   +5 more
doaj   +1 more source

Little Red Dots or Brown Dwarfs? NIRSpec Discovery of Three Distant Brown Dwarfs Masquerading as NIRCam-selected Highly Reddened Active Galactic Nuclei

The Astrophysical Journal Letters, 2023
Cold, substellar objects such as brown dwarfs have long been recognized as contaminants in color-selected samples of active galactic nuclei (AGNs). In particular, their near- to mid-infrared colors (1–5 μ m) can closely resemble the V-shaped ( f _λ ...
Danial Langeroodi, Jens Hjorth
doaj   +1 more source

Atmospheric Habitable Zones in Y Dwarf Atmospheres [PDF]

The Astrophysical Journal, 2017
Abstract We use a simple organism lifecycle model to explore the viability of an atmospheric habitable zone (AHZ), with temperatures that could support Earth-centric life, which sits above an environment that does not support life. To illustrate our model, we use a cool Y dwarf atmosphere, such as WISE J085510.83–0714442.5, whose 4.5–5.2
Jack S. Yates, Paul I. Palmer, Beth Biller, Charles S. Cockell   +3 more
openaire   +2 more sources

Forever young white dwarfs: When stellar ageing stops [PDF]

, 2021
White dwarf stars are the most common end point of stellar evolution. The ultramassive white dwarfs are of special interest as they are related to type Ia supernovae explosions, merger events, and fast radio bursts. Ultramassive white dwarfs are expected
Santiago Torres, Roberto Raddi, Rebassa Mansergas, Alberto, Cheng, Sihao, Alejandro H. Córsico, Pier-Emmanuel Tremblay, Althaus, Leandro Gabriel, María E. Camisassa, Tremblay, P. E., Torres Gil, Santiago, Sihao Cheng, Corsico, Alejandro Hugo, Althaus, Leandro G., Tremblay, Pier Emmanuel, Raddi, Roberto, Leandro G. Althaus, Camisassa, María E., Torres, Santiago, Córsico, Alejandro H., Tremblay, Pier-Emmanuel, Rebassa-Mansergas, Alberto, Alberto Rebassa-Mansergas, Camisassa, María Eugenia   +22 more
core   +1 more source

THE COLDEST BROWN DWARF (OR FREE-FLOATING PLANET)?: THE Y DWARF WISE 1828+2650 [PDF]

The Astrophysical Journal, 2013
37 pages, 10 figures, accepted for Astrophysical Journal, Feb ...
Beichman, Charles A., Gelino, Christopher R., Kirkpatrick, J. Davy, Barman, Travis S., Marsh, Kenneth A., Cushing, Michael C., Wright, E. L.   +6 more
openaire   +2 more sources

Infrared Excesses around Bright White Dwarfs from Gaia and unWISE. II [PDF]

, 2021
Infrared excesses around white dwarf stars indicate the presence of various astrophysical objects of interest, including companions and debris disks. In this second paper of a series, we present follow-up observations of infrared excess candidates from ...
Kleinman, Scot J., Rebassa Mansergas, Alberto, Leggett, Sandy, Nitta, Atsuko, Bonsor, Amy, Dennihy, Erik, Hodgkin, Simon, Lai, Samuel, Xu, Siyi, Leggett, S. K., Rebassa-Mansergas, Alberto, Rogers, Laura K., Kleinman, Scott J., Rogers, L. K.   +13 more
core   +1 more source

J-PLUS : spectral evolution of white dwarfs by PDF analysis [PDF]

, 2022
Aims. We estimated the spectral evolution of white dwarfs with effective temperature using the Javalambre Photometric Local Universe Survey (J-PLUS) second data release (DR2), which provides 12 photometric optical passbands over 2176 deg2. Methods.
Ederoclite, Alessandro, A. Mar??n-Franch, López-Sanjuan, Carlos, López-Sanjuan, C., F. M. Jiménez-Esteban, Gaensicke, B. T., Dupke, R. A., C. Hern??ndez-Monteagudo, Tremblay, Pier Emmanuel, Vázquez Ramió, H., Dupke, Renato A., J. M. Carrasco, Alcaniz, J., L. Sodr??, Jiménez-Esteban, F. M., Moles, M., J. Alcaniz, A. J. Cenarro, Ederoclite, A., A. Ederoclite, M. Moles, Daflon, S., Varela, J., A. Marín-Franch, F. M. Jim??nez-Esteban, B. T. G??nsicke, Civera, T., T. Civera, Daflon, Simone, Gentile Fusillo, N. P., R. A. Dupke, R. E. Angulo, D. Crist??bal-Hornillos, H. V??zquez Rami??, Tremblay, P.-E., Cristóbal-Hornillos, D., S. Daflon, C. Hernández-Monteagudo, Marín-Franch, Antonio, D. Cristóbal-Hornillos, Hernández-Monteagudo, Carlos, Sodré, L., Marín-Franch, A., Hernández-Monteagudo, C., C. López-Sanjuan, N. P. Gentile Fusillo, Carrasco, J. M., Alcaniz, Jailson, Gänsicke, Boris T., Moles, Mariano, Vázquez Ramió, Héctor, Angulo, Raul E., Cenarro, A. J., Carrasco, María Jesús, H. Vázquez Ramió, Gentile Fusillo, Nicola P., Angulo, R. E., Varela, Jesús, P. -E. Tremblay, Cristóbal-Hornillos, David, Jiménez-Esteban, Francisco M., P.-E. Tremblay, L. Sodré, Sodré, Laerte Jr., B. T. Gänsicke, J. Varela   +65 more
core   +1 more source

Y Gem: A White Dwarf Symbiotic Star?

The Astrophysical Journal, 2022
Abstract In this work we conduct a thorough investigation of the X-ray and ultraviolet (UV) properties of Y Gem based on six archival XMM-Newton and Chandra observations to explore the nature of the system. The results show that Y Gem has strong (1032–34 erg s−1) X-ray emission, including a hard (with a maximum emission temperature of 8 ...
Zhuo-li Yu, Xiao-jie Xu, Yong Shao, Q. Daniel Wang, Xiang-Dong Li   +4 more
openaire   +1 more source

Self-consistent Models of Y Dwarf Atmospheres with Water Clouds and Disequilibrium Chemistry

The Astrophysical Journal, 2023
Y dwarfs are the coolest spectral class of brown dwarf. They have effective temperatures less than 500 K, with the coolest detection as low as ∼250 K.
Brianna Lacy, Adam Burrows
doaj   +1 more source

The minimum Jeans mass, brown dwarf companion IMF, and predictions for detection of Y-type dwarfs [PDF]

Astronomy & Astrophysics, 2008
6 pages, 2 figures, A& ...
Zuckerman, Ben, Song, Inseok
openaire   +2 more sources