This is… huh.

Smallest, densest white dwarf ever discovered packs the sun’s mass into a moon-size stellar corpse

ZTF J1901+1458 is  about 130 light years away, has a diameter of only 2,670 miles and a mass of 1.35 times the sun. This is the most massive white dwarf so far discovered; the mass actually compresses it down to a smaller diameter than lower mass white dwarfs. As it cools (its current surface temperature is about 46,000 kelvin), it will compress further and either detonate as a Type Ia supernova or settle down into a neutron star.

Neat!