HD 57821

HD 57821 is a single star in the southern constellation of Canis Major. It has a blue-white hue and is faintly visible to the naked eye with an apparent visual magnitude of 4.94. Based on parallax measurements, the distance to this object is approximately 480 light years. It is drifting further away with a radial velocity of +33 km/s, having come to within 21.83 pc some 4.3 million years ago.

The stellar classification of this star is B5 II/III, which matches the spectrum of a giant/bright giant although stellar models suggest it may still be on the main sequence. It has over four times the mass of the Sun and is 291 million years old. The star has a high rate of spin, showing a projected rotational velocity of 116 km/s. It is radiating around 489 times the luminosity of the Sun from its photosphere at an effective temperature of $−0.039$.