Discovery of a Cool, Massive, and Metal-rich DAZ White Dwarf
نویسندگان
چکیده
منابع مشابه
Chemical abundances in cool metal rich disk dwarf stars
The present study of spectra of twelve metal-rich cool dwarf stars, carefully selected in order to cover a range of temperatures (∼ 4400 − 6000 K), is a follow up on Feltzing & Gustafsson (1998) with the aim to understand the apparent over-ionization and anomalous elemental abundances found by them for the K dwarf stars in their sample. Our method of analysis employs synthetic spectra of the fu...
متن کاملExcess Infrared Radiation from the Massive Daz White Dwarf GD 362: A Debris Disk?
We report the discovery of excess K-band radiation from the massive DAZ white dwarf star GD 362. Combining infrared photometric and spectroscopic observations, we show that the excess radiation cannot be explained by a stellar or substellar companion, and is likely to be caused by a debris disk. This would be only the second such system known, discovered 18 years after G29-38, the only single w...
متن کاملNon-Ideal Equation of State, Refraction and Opacities in Very Cool, Helium-Rich White Dwarf Atmospheres
The atmospheres of cool, helium-rich white dwarfs constitute an exotic and poorly explored physical regime of stellar atmospheres. Under physical conditions where the temperature varies from 1000K to 10000K, the density can reach values as large as 2 g/cm, and the pressure is as high as 1 Mbar, the atmosphere is no longer an ideal gas and must be treated as a dense fluid. Helium atoms become st...
متن کاملHelium Nova on a Massive White Dwarf
The 2000 outburst of V445 Puppis shows unique properties, such as absence of hydrogen, enrichment of helium and carbon, slow development of the light curve with a small amplitude that does not resemble any classical novae. This object has been suggested to be the first example of helium novae. We calculate theoretical light curves of helium novae and reproduce the observational light curve of V...
متن کاملOn the Dissociation Equilibrium of H2 in Very Cool, Helium-Rich White Dwarf Atmospheres
We investigate the dissociation equilibrium of H2 in very cool, helium-rich white dwarf atmospheres. We present the solution of the non-ideal chemical equilibrium for the dissociation of molecular hydrogen in a medium of dense helium. We find that at the photosphere of cool white dwarfs of Teff = 4000K, the non-ideality results in an increase of the mole fraction of molecular hydrogen by up to ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2004
ISSN: 0004-637X,1538-4357
DOI: 10.1086/427080