Neutron star

SGR 1806-20

Also SGR 1806−20

Open in Ouranos

A magnetar, a neutron star with an extreme magnetic field, at a disputed distance: about as far as the Milky Way's centre, perhaps nearly twice that.

Measured

Distance: about 28,400 light-years (published estimates 23,500–49,000)
Constellation: Sagittarius
Position (J2000): RA 18h 08m 39s, Dec −20.41°

How far, from the Sun

About 28,400 light-years. To cross it:

Light28,400 years
Voyager 1's speed505 million years
Driving at 100 km/h307 billion years

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

Facts

Its giant flare on 27 December 2004 was the brightest event recorded from beyond the Solar System up to then.
That flare measurably disturbed Earth's upper atmosphere from tens of thousands of light years away.
Published estimates run from about 7 to 15 kiloparsecs; the widest limits allow about 6 to 19.

Where this comes from

Bibby et al. 2008 (8.7 +1.8/−1.5 kpc); Corbel & Eikenberry 2004 (15.1 +1.8/−1.3 kpc); limits: Cameron et al. 2005 (over 6.4 kpc), Svirski et al. 2011 (9.4–18.6 kpc); read 2026-10-31

Every catalogue Ouranos draws is credited on the credits page.