LSPM J0207+3331
LSPM J0207+3331 is, as of 2019, the oldest and coldest known white dwarf star to host a circumstellar disk, located 145 light-years from Earth.
It was discovered in October 2018 by a volunteer participating in the Backyard Worlds citizen science project.
The star has a circumstellar disk despite being 3 billion years old. The infrared excess in the spectrum is consistent with two rings at different temperatures: an outer colder ring with a temperature of 480 K and an inner ring with a temperature between 550–1400 K. It may be a debris disk created from asteroids broken apart by the star's gravity.
This star has been studied with the Keck telescope and is the object of ongoing research. A paper has been accepted by The Astrophysical Journal Letters.
