A bright X-ray source is found in Cygnus
Sounding-rocket surveys carrying X-ray detectors above the atmosphere for a few minutes at a time found one of the brightest X-ray sources in the sky in the constellation Cygnus. Nothing about the detection identified the source as compact or unusual; X-ray astronomy at the time could not localise a source well enough to match it to anything visible. The identification took another seven years and required radio astronomy.
Historical — it happened, and the record is settled.
Subjects
- Cygnus X-1 · celestial body · Constellation Cygnus, as seen from Earth · not located
Evidence
Partly verified — Core facts are sourced; some optional detail is deliberately absent.
Cygnus X-1 contains a 21 solar mass black hole - implications for massive star winds
Revises the distance to Cygnus X-1 by radio parallax and with it the mass of the compact object, to approximately 21 solar masses. V55 VERIFICATION BASIS: not consulted in session; no research tool was available. Title wording, volume and page are from recall and must be checked; the near-maximal spin inference reported alongside is model-dependent.
Science · 2021 · Partly verified
J. C. A. Miller-Jones et al., Science 371, 1046 (2021)
Recorded on Cygnus X-1
- A bright X-ray source is found in Cygnus
- Cygnus X-1 is localised and weighed
Related
Related because they share a subject in the Atlas — never because the text looks similar.
- Cygnus X-1 is localised and weighed · 1971-1972