Within Ursa Minor, H1504+65, a white dwarf with the hottest known surface temperature in the universe at 200,000 K, was documented.

Ursa Minor, also known as the Little Bear, is a constellation located in the far northern sky. As with the Great Bear, the tail of the Little Bear may also be seen as the handle of a ladle, hence the North American name, Little Dipper: seven stars with four in its bowl like its partner the Big Dipper. Ursa Minor was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and remains one of the 88 modern constellations. Ursa Minor has traditionally been important for navigation, particularly by mariners, because of Polaris being the north pole star.

H1504+65 is an enigmatic peculiar star in the constellation Ursa Minor. With a surface temperature of 200,000 K (360,000°F) and an atmosphere composed of carbon, oxygen and 2% neon, it is the second hottest white dwarf ever discovered, with only RX J0439.8−6809 being hotter. It is thought to be the stellar core of a post-asymptotic giant branch star, though its composition is unexplainable by current models of stellar evolution.

A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: in an Earth-sized volume, it packs a mass that is comparable to the Sun. No nuclear fusion takes place in a white dwarf; what light it radiates is from its residual heat. The nearest known white dwarf is Sirius B, at 8.6 light years, the smaller component of the Sirius binary star. There are currently thought to be eight white dwarfs among the one hundred star systems nearest the Sun. The unusual faintness of white dwarfs was first recognized in 1910. The name white dwarf was coined by Willem Jacob Luyten in 1922.

January 27 is the 27th day of the year in the Gregorian calendar; 338 days remain until the end of the year.