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Black hole

V4641 Sagittarii

Also V4641 Sgr · SAX J1819.3-2525

Open in Ouranos

A black hole of about 6 times the Sun's mass in orbit with a hot blue star.

Measured

Distance
about 19,280 light-years (published estimates 16,690–22,810)
Constellation
Sagittarius
Position (J2000)
RA 18h 19m 22s, Dec −25.41°

How far, from the Sun

About 19,300 light-years. To cross it:

  • Light19,300 years
  • Voyager 1's speed343 million years
  • Driving at 100 km/h208 billion years

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

Facts

  • In 1999 it flared up dramatically within a matter of hours, then faded again.
  • Its distance comes from a Gaia parallax: the tiny yearly shift in its position as the Earth circles the Sun.

Where this comes from

  • Gaia DR3 parallax 0.1692 ± 0.0262 mas, Gaia DR3 4053096388919082368 (Gaia Collaboration 2023, A&A 674, A1)
  • This research has made use of the SIMBAD database, CDS, Strasbourg, France (Wenger et al. 2000, A&AS 143, 9).
  • This research has made use of the VizieR catalogue access tool, CDS, Strasbourg, France (DOI: 10.26093/cds/vizier).

Every catalogue Ouranos draws is credited on the credits page.