Observations of Ultracool White Dwarfs

B. R. Oppenheimer; D. Saumon; S. T. Hodgkin; R. F. Jameson; N. C. Hambly; G. Chabrier; A. V. Filippenko; A. L. Coil; M. E. Brown

doi:10.1086/319718

Observations of Ultracool White Dwarfs

B. R. Oppenheimer, D. Saumon, S. T. Hodgkin, R. F. Jameson, N. C. Hambly, G. Chabrier, A. V. Filippenko, A. L. Coil, M. E. Brown

School of Physics and Astronomy

Research output: Contribution to journal › Article › peer-review

Abstract

We present new spectroscopic and photometric measurements of the white dwarfs LHS 3250 and WD 0346+246. Along with F351-50, these white dwarfs are the coolest ones known, all with effective temperatures below 4000 K. Their membership in the Galactic halo population is discussed, and detailed comparisons of all three objects with new atmosphere models are presented. The new models consider the effects of mixed H/He atmospheres and indicate that WD 0346+246 and F351-50 have predominantly helium atmospheres with only traces of hydrogen. LHS 3250 may be a double degenerate whose average radiative temperature is between 2000 and 4000 K, but the new models fail to explain this object.

Original language	English
Pages (from-to)	448-456
Journal	Astrophysical Journal
Volume	550
Issue number	1
DOIs	https://doi.org/10.1086/319718
Publication status	Published - 1 Mar 2001

Keywords / Materials (for Non-textual outputs)

Stars: Fundamental Parameters
stars: individual (LHS 3250
WD 0346+246)
Stars: White Dwarfs

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10.1086/319718

http://adsabs.harvard.edu/abs/2001ApJ...550..448O

Cite this

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title = "Observations of Ultracool White Dwarfs",

abstract = "We present new spectroscopic and photometric measurements of the white dwarfs LHS 3250 and WD 0346+246. Along with F351-50, these white dwarfs are the coolest ones known, all with effective temperatures below 4000 K. Their membership in the Galactic halo population is discussed, and detailed comparisons of all three objects with new atmosphere models are presented. The new models consider the effects of mixed H/He atmospheres and indicate that WD 0346+246 and F351-50 have predominantly helium atmospheres with only traces of hydrogen. LHS 3250 may be a double degenerate whose average radiative temperature is between 2000 and 4000 K, but the new models fail to explain this object.",

keywords = "Stars: Fundamental Parameters, stars: individual (LHS 3250, WD 0346+246), Stars: White Dwarfs",

author = "Oppenheimer, {B. R.} and D. Saumon and Hodgkin, {S. T.} and Jameson, {R. F.} and Hambly, {N. C.} and G. Chabrier and Filippenko, {A. V.} and Coil, {A. L.} and Brown, {M. E.}",

year = "2001",

month = mar,

day = "1",

doi = "10.1086/319718",

language = "English",

volume = "550",

pages = "448--456",

journal = "Astrophysical Journal",

issn = "0004-637X",

publisher = "IOP Publishing",

number = "1",

}

TY - JOUR

T1 - Observations of Ultracool White Dwarfs

AU - Oppenheimer, B. R.

AU - Saumon, D.

AU - Hodgkin, S. T.

AU - Jameson, R. F.

AU - Hambly, N. C.

AU - Chabrier, G.

AU - Filippenko, A. V.

AU - Coil, A. L.

AU - Brown, M. E.

PY - 2001/3/1

Y1 - 2001/3/1

N2 - We present new spectroscopic and photometric measurements of the white dwarfs LHS 3250 and WD 0346+246. Along with F351-50, these white dwarfs are the coolest ones known, all with effective temperatures below 4000 K. Their membership in the Galactic halo population is discussed, and detailed comparisons of all three objects with new atmosphere models are presented. The new models consider the effects of mixed H/He atmospheres and indicate that WD 0346+246 and F351-50 have predominantly helium atmospheres with only traces of hydrogen. LHS 3250 may be a double degenerate whose average radiative temperature is between 2000 and 4000 K, but the new models fail to explain this object.

AB - We present new spectroscopic and photometric measurements of the white dwarfs LHS 3250 and WD 0346+246. Along with F351-50, these white dwarfs are the coolest ones known, all with effective temperatures below 4000 K. Their membership in the Galactic halo population is discussed, and detailed comparisons of all three objects with new atmosphere models are presented. The new models consider the effects of mixed H/He atmospheres and indicate that WD 0346+246 and F351-50 have predominantly helium atmospheres with only traces of hydrogen. LHS 3250 may be a double degenerate whose average radiative temperature is between 2000 and 4000 K, but the new models fail to explain this object.

KW - Stars: Fundamental Parameters

KW - stars: individual (LHS 3250

KW - WD 0346+246)

KW - Stars: White Dwarfs

U2 - 10.1086/319718

DO - 10.1086/319718

M3 - Article

SN - 0004-637X

VL - 550

SP - 448

EP - 456

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 1

ER -

Observations of Ultracool White Dwarfs

Abstract

Keywords / Materials (for Non-textual outputs)

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