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Black hole

V404 Cygni

Also GS 2023+338 · Nova Cygni 1938

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A black hole that flares up every few decades as it gulps gas from a companion star.

Measured

Distance
about 7,800 light-years (published estimates 7,340–8,250)
Constellation
Cygnus
Position (J2000)
RA 20h 24m 04s, Dec +33.87°

How far, from the Sun

About 7,800 light-years. To cross it:

  • Light7,800 years
  • Voyager 1's speed139 million years
  • Driving at 100 km/h84.2 billion years

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

Facts

  • It has about 9 times the Sun's mass; its companion star orbits every 6.5 days.

How it was found

  • It erupted in 1938, 1956, 1989 and 2015. The 1938 outburst was logged as a nova, the 1956 one was found later on old plates, and the last two were watched in X-rays.

Where this comes from

  • Miller-Jones et al. 2009, VLBA radio parallax (2.39 ± 0.14 kpc)

Every catalogue Ouranos draws is credited on the credits page.