Star

V838 Monocerotis

Also V838 Mon

Open in Ouranos

A star that brightened suddenly in 2002, lighting up the dust around it in a spectacular 'light echo' Hubble filmed for years.

Measured

Distance: about 20,010 light-years (published estimates 18,220–22,190)
Constellation: Monoceros
Position (J2000): RA 7h 04m 05s, Dec −3.85°

How far, from the Sun

About 20,000 light-years. To cross it:

Light20,000 years
Voyager 1's speed356 million years
Driving at 100 km/h216 billion years

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

Facts

The outburst may have been two stars merging.
Its distance comes from a radio parallax, measured by radio telescopes thousands of kilometres apart working as one.

Where this comes from

Maser parallax 0.163 ± 0.016 mas (Reid et al. 2019, ApJ 885, 131)
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.