Alvan Graham Clark sees Sirius B
Testing a newly figured 18.5-inch refractor at Cambridgeport, Massachusetts, Clark resolved a faint companion beside Sirius - the object whose motion had already been inferred from the wobble of Sirius A. It was the first white dwarf ever seen, though nothing about it could be understood for another sixty years: a star of roughly solar mass in a body about the size of the Earth implied densities that classical physics had no way to support.
Historical — it happened, and the record is settled.
Subjects
- Sirius B · celestial body · Constellation Canis Major, as seen from Earth · not located
- White dwarf · celestial body · Galactic · not located
Evidence
Partly verified — Core facts are sourced; some optional detail is deliberately absent.
The Sirius System and its Astrophysical Puzzles: Hubble Space Telescope and Ground-Based Astrometry
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.
The Astrophysical Journal (preprint arXiv:1703.10625); with Rice University ASTR 350 lecture notes · 2017 · Partly verified
arXiv:1703.10625; M. Baring, Rice University ASTR 350 lecture notes on white dwarfs (2025 edition)
Recorded on Sirius B
- Alvan Graham Clark sees Sirius B
- A maximum mass for ideal white dwarfs is published
Related
Related because they share a subject in the Atlas — never because the text looks similar.