SDSS J121606.5+280648.5: A helium-core white dwarf in an eclipsing binary system?

摘要

A comparison of Palomar Observatory Sky Survey (POSS) and Sloan Digital Sky Survey (SDSS) images showed SDSS J121606. 5+280648. 5 to have increased in brightness by nearly two magnitudes since 1955. SDSS J121606. 5+280648. 5 turned out to be a low-mass white dwarf having a less luminous cool companion, probably a late-type Main Sequence dwarf. A possible explanation of brightening is that the companion eclipsed the white dwarf at the time the POSS plate was obtained. If SDSS J121606. 5+280648. 5 is an eclipsing binary, further study should help establish circumstances in which rapid mass loss occurs on the Red Giant Branch (RGB).