Sagittarius A Star Proper Motion
Uses precision radio astrometry to constrain the motion of Sagittarius A*, supporting its identification with the Milky Way's central massive black hole.
Historical biography archive · Updated 2026-11-03
Mark Reid Biography and Timeline
Follow Mark Reid through 2 dated historical records for United States of America.
Mark Reid, historical timeline
A chronological timeline drawn from matching World History Database records.
2Distinct records
1 of 1Page
2009–2011Years on this page
2009
2011
Cygnus X-1 Parallax
Measures the trigonometric parallax and proper motion of Cygnus X-1, enabling substantially improved estimates of the system's distance and black hole properties.
Records, sources and methodology
These dates and descriptions come from the historical_events database. Exact duplicate records have been collapsed. Names are grouped by the country, Name 2 and Name 1 fields; records with missing Name 2 cannot be reliably assigned to an individual biography. Check the underlying sources before formal citation.