TY Coronae Borealis, also known as Ross 808, is a

variable Variable may refer to: * Variable (computer science), a symbolic name associated with a value and whose associated value may be changed * Variable (mathematics), a symbol that represents a quantity in a mathematical expression, as used in many ...

white dwarf

star A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...

of the DAV (or ZZ Ceti) type in the constellation Corona Borealis. It has a surface temperature of 11,213 ± 130 K and a mass around 70% times that of the Sun, but only 1.1% of its diameter. It is 107 light-years distant from Earth. It was confirmed as a variable star in 1976.

References

Corona Borealis Pulsating white dwarfs Coronae Borealis, TY {{whitedwarf-star-stub