The Extremely Low Luminosity White Dwarf ESO 439-26

Details The Extremely Low Luminosity White Dwarf ESO 439-26 The Extremely Low Luminosity White Dwarf ESO 439-26

Dec 1995

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995apj...455l.159r&link_type=abstract

Astrophysical Journal Letters v.455, p.L159

Astronomy and Astrophysics

Astronomy

28

Stars: Evolution, Stars: Individual Alphanumeric: Eso 439-26, Stars: White Dwarfs

Scientific paper

We present a detailed analysis of the extremely low luminosity white dwarf ESO 439-26. The measured trigonometric parallax of pi = 0."0237 +/- 0."0030, together with the observed V magnitude of 20.52, yields an absolute visual magnitude of MV = 17.4 +/- 0.3. ESO 439-26 thus lies more than 1 mag faintward of the observed cutoff of the white-dwarf luminosity function in the Galactic disk and could therefore be the coolest and hence oldest white dwarf ever detected. However, we show from a detailed analysis of the optical energy distribution that the intrinsic low luminosity of ESO 439-26 is the result of its small radius, or large mass. Our best solution is reached with Teff = 4560 +/- 100 K, log g = 9.04 +/- 0.14, and a pure-helium atmospheric composition. Evolutionary models are used to derive a mass of M = 1.21 +/- 0.07 M&sun; and a cooling age of 6.4 +/- 0.3 Gyr, a value that is smaller than the current estimates of the age of the Galactic disk.

Affiliated with

Also associated with

No associations

Rating

The Extremely Low Luminosity White Dwarf ESO 439-26 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The Extremely Low Luminosity White Dwarf ESO 439-26, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Extremely Low Luminosity White Dwarf ESO 439-26 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1258709