Andromeda
Log inJoin

White dwarf

Sirius B

Also Alpha Canis Majoris B · WD 0642-166

Open in Ouranos
Sirius B — Hubble, visible light; Sirius B is the faint dot
Hubble, visible light; Sirius B is the faint dot. Credit: NASA, ESA, H. Bond (STScI), and M. Barstow (University of Leicester). Licence: CC BY 4.0. Source

The white dwarf companion of Sirius, the brightest star in the night sky.

Measured

Distance
8.6 light-years
Constellation
Canis Major
Position (J2000)
RA 6h 45m 09s, Dec −16.72°

How far, from the Sun

8.6 light-years. To cross it:

  • Light8.6 years
  • Voyager 1's speed153,000 years
  • Driving at 100 km/h92.8 million years

Voyager 1 at the speed it moved outward over the year to 2026-10-25 (JPL Horizons). Driving: nonstop, never refuelling.

Facts

  • It packs about 1.02 Suns of mass into a ball slightly smaller than Earth.
  • Friedrich Bessel predicted it in 1844 from Sirius's wobble; Alvan Graham Clark first saw it in 1862.
  • It is the nearest known white dwarf to the Sun.

Where this comes from

  • Hipparcos parallax of Sirius, 379.21 ± 1.58 mas (van Leeuwen 2007, A&A 474, 653)

Every catalogue Ouranos draws is credited on the credits page.