Results 71 to 80 of about 22,040,331 (192)

Mid-infrared followup of cold brown dwarfs: Diversity in age, mass and metallicity

EPJ Web of Conferences, 2011
We use Spitzer IRAC 3.6–8.0 μm photometry of late-type T dwarfs to investigate various trends which can aid the planning and interpretation of infrared (IR) surveys for the coldest T or Y dwarfs. Brown dwarfs with effective temperature (Teff)50% of their
Pinfield D.J., Jones H.R.A., Warren S.J., Marley M.S., Saumon D., Burningham B., Leggett S.K., Smart R.L.   +7 more
doaj   +1 more source

JWST Observations of the Enigmatic Y-Dwarf WISE 1828+2650. I. Limits to a Binary Companion

The Astrophysical Journal, 2023
The Y-dwarf WISE 1828+2650 is one of the coldest known brown dwarfs with an effective temperature of ∼300 K. Located at a distance of just 10 pc, previous model-based estimates suggest WISE1828+2650 has a mass of ∼5–10 M _J , making it a valuable ...
Matthew De Furio, Ben Lew, Charles Beichman, Thomas Roellig, Geoffrey Bryden, David Ciardi, Michael Meyer, Marcia Rieke, Alexandra Greenbaum, Jarron Leisenring, Jorge Llop-Sayson, Marie Ygouf, Loic Albert, Martha Boyer, Daniel Eisenstein, Klaus Hodapp, Scott Horner, Doug Johnstone, Doug Kelly, Karl Misselt, George Rieke, John Stansberry, Erick Young   +22 more
doaj   +1 more source

Spitzer + Hubble Space Telescope Parallaxes of 13 Late T and Y Dwarfs

The Astronomical Journal
We present astrometric measurements for 13 cold brown dwarfs in the solar neighborhood ( d  
Federico Marocco, J. Davy Kirkpatrick, Richard L. Smart, Adam C. Schneider, Dan Caselden, Edgardo Costa, Michael C. Cushing, Maximiliano Dirk, Peter R. M. Eisenhardt, Jacqueline K. Faherty, Christopher R. Gelino, Marc J. Kuchner, Aaron M. Meisner, Rene A. Mendez, Robert A. Stiller, Edward L. Wright   +15 more
doaj   +1 more source

A New Look at Magnetic White Dwarfs [PDF]

, 2018
The 21st European Workshop on White Dwarfs was held in Austin, TX from July 23rd to 27th of 2018We present a homogeneous photometric analysis of a large sample of magnetic DA white dwarfs as well as selected results from a spectrophotometric analysis ...
Hardy, F., Jordan, S., Dufour, P.
core   +1 more source

The Sonora Substellar Atmosphere Models. VI. Red Diamondback: Extending Diamondback with SPHINX for Brown Dwarf Early Evolution

The Astrophysical Journal
We extend the Sonora Diamondback brown dwarf evolution models to higher effective temperatures to treat the evolution of younger, higher-mass objects. Due to an upper temperature limit of T _eff  =  2400 K in the original Sonora Diamondback model grid ...
C. Evan Davis, Jonathan J. Fortney, Aishwarya Iyer, Sagnick Mukherjee, Caroline V. Morley, Mark S. Marley, Michael Line, Philip S. Muirhead   +7 more
doaj   +1 more source

Sub-stellar objects with habitable-zone temperatures: A new search for Y dwarfs in WISE

EPJ Web of Conferences, 2013
A method is defined for using the maximum sensitivity of WISE to find late T and Y dwarfs. This requires a WISE detection only in the W2-band and uses the statistical properties of the WISE multi-frame measurements and profile fit photometry to reject ...
Day-Jones Avril, Gomes Joana, Pinfield David   +2 more
doaj   +1 more source

A uvbyCaHβ CCD Analysis of the Open Cluster Standard, M67, and Its Relation to NGC 752

The Astronomical Journal, 2023
Precision CCD uvbyCa H β photometry is presented of the old cluster, M67, covering one square degree with typical internal precision at the 0.005–0.020 mag level to V ∼ 17.
Bruce A. Twarog, Barbara J. Anthony-Twarog, Constantine P. Deliyannis   +2 more
doaj   +1 more source

Spectrometric composition of nearby K dwarfs

, 2006
We have obtained relatively high resolution spectra of Northern hemisphere K dwarfs. This is the first spectrometric project dedicated only to K dwarfs. Earlier studies have concentrated on more massive F and G dwarfs.
Y. J. Liu, G. Zhao, J. R. Shi, E. Kotoneva   +3 more
core   +1 more source

Properties of the Coolest Dwarfs [PDF]

, 2008
Eleven years after the discovery of the first T dwarf, a population of ultracool L and T dwarfs has been identified that is large enough to show a range of atmospheric properties.
Lodieu, N., Golimowski, D., Pinfield, D.J., Warren, S.J., Marley, M., Leggett, S.K., Saumon, D., Freedman, R., Geballe, T., Stephens, D.   +9 more
core   +1 more source

High-precision Atmospheric Characterization of a Y Dwarf with JWST NIRSpec G395H Spectroscopy: Isotopologue, C/O Ratio, Metallicity, and the Abundances of Six Molecular Species

The Astronomical Journal
The launch of the James Webb Space Telescope (JWST) marks a pivotal moment for precise atmospheric characterization of Y dwarfs, the coldest brown dwarf spectral type.
Ben W. P. Lew, Thomas Roellig, Natasha E. Batalha, Michael Line, Thomas Greene, Sagnick Murkherjee, Richard Freedman, Michael Meyer, Charles Beichman, Catarina Alves de Oliveira, Matthew De Furio, Doug Johnstone, Alexandra Z. Greenbaum, Mark Marley, Jonathan J. Fortney, Erick T. Young, Jarron Leisenring, Martha Boyer, Klaus Hodapp, Karl Misselt, John Stansberry, Marcia Rieke   +21 more
doaj   +1 more source