An H II region or HII region is a region of interstellar atomic hydrogen that is ionized.
LBV 1806-20 is a candidate luminous blue variable (LBV) and likely binary star located nearly 40,000 light-years from the Sun, towards the center of the Milky Way.
Luminous blue variables (LBVs) are massive evolved stars that show unpredictable and sometimes dramatic variations in both their spectra and brightness.
A magnetar is a type of neutron star with an extremely powerful inferred magnetic field (\sim 10^ - 10^ G).
The Milky Way is the galaxy that contains our Solar System.
A molecular cloud, sometimes called a stellar nursery (if star formation is occurring within), is a type of interstellar cloud, the density and size of which permit the formation of molecules, most commonly molecular hydrogen (H2).
SGR 1806-20 is a magnetar, a type of neutron star with a very powerful magnetic field, that was discovered in 1979 and identified as a soft gamma repeater.
A soft gamma repeater (SGR) is an astronomical object which emits large bursts of gamma-rays and X-rays at irregular intervals.
The W31 was an American nuclear warhead used for two US missiles and as an atomic demolition munition.
Westerhout 31, also known as W31, is a complex of star formation regions of the Milky Way located in the constellation of Sagittarius.
1806-20 (originally named the SGR 1806-20 cluster) is a heavily obscured star cluster on the far side of the Milky Way, approximately 50,000 light years distant.