NGC 2040 (also known as LH 88 and ESO 56-EN164) is an open star cluster with nebulosity, located about 160,000 light years away in the Large Magellanic Cloud (LMC), toward the constellation of Dorado.
These bright stars of this young stellar grouping, shining through what looks like a haze in the night sky, are part of the largest known star formation regions of the Large Magellanic Cloud, a dwarf satellite galaxy of, and about 100 times smaller than our Milky Way.
It is essentially a very loose star cluster whose stars have a common origin and are drifting together through space. There are three different types of stellar associations defined by their stellar properties. NGC 2040 is an OB association, a grouping that usually contains 10–100 stars of type O and B — these are high-mass stars that have short but brilliant lives. It is thought that most of the stars in the Milky Way were born in OB associations.
There are several such groupings of stars in the LMC. Just like the others, LH 88 consists of several high-mass young stars in a large nebula of partially ionised hydrogen gas, and lies in what is known to be a supergiant shell of gas called LMC 4.
Over a period of several million years, thousands of stars may form in these supergiant shells, which are the largest interstellar structures in galaxies. The shells themselves are believed to have been created by strong stellar winds and clustered supernova explosions of massive stars that blow away surrounding dust and gas, and in turn trigger further episodes of star formation.