Sirius B

Assembled from 17 blocks · 2 evidence · 12 related

1. Story
2. The companion of Sirius A and the first white dwarf ever observed, seen by Alvan Graham Clark on 31 January 1862 while testing a new 18.5-inch refractor. Its existence had been inferred earlier from the wobble of Sirius A. Its significance is that it forced the physics: a star of roughly one solar mass packed into a body about the size of the Earth, with an effective temperature near 25,000 K, implies a density that no classical model of matter could explain, and the resolution - electron degeneracy - arrived only with quantum mechanics in the 1920s. It is the concrete object behind an abstract limit, and it is bright enough and close enough that its mass and radius are among the best-measured of any white dwarf. Not a place on Earth.
3. Knowledge
4. White dwarf
5. Sirius B
6. Connections
7. White dwarf
8. Alvan Graham Clark sees Sirius B
9. Chandrasekhar limit
10. Degeneracy pressure
11. Red giant and asymptotic giant branch
12. Sirius B
13. Alvan Graham Clark sees Sirius B
14. A maximum mass for ideal white dwarfs is published
15. Evidence
16. Supports the identification of Sirius B as the first observed white dwarf and the Stefan-Boltzmann radius estimate of about 0.008 solar radii at roughly 25,000 K. Neither source was fetched; the 31 January 1862 discovery date and the 18.5-inch aperture come from reference summaries.
17. Derives an upper mass bound for a body supported by relativistic electron degeneracy. Journal, volume and pages come from an ADS scan listing seen via search; the paper was not fetched, and the statement that its own derived value was about 0.91 solar masses rests on a secondary summary.