OB star

This includes massive OB stars, supergiants, interacting binary stars and supernova progenitors.

The hot OB stars that are created ionize the gas of the interstellar medium, and form H II regions.

The spiral arms are sites of ongoing star formation and are brighter than the surrounding disk because of the young, hot OB stars that inhabit them.

The source of ionisation is the population of massive stars (more than one hundred OB stars have been identified so far) that also occupy the central parsec.

OB stars are hot, massive stars of spectral types O or early-type B which form in loosely organized groups called OB associations.

Ultraviolet astronomy is best suited to the study of thermal radiation and spectral emission lines from hot blue stars (OB stars) that are very bright in this wave band.

Compared to the Sun, Tau Scorpii is a massive OB star with 15 times the Sun's mass and more than six times the radius of the Sun.

One is that the ice giants were not created by core accretion but from instabilities within the original protoplanetary disc and later had their atmospheres blasted away by radiation from a nearby massive OB star.

The hottest and most massive of the newly formed stars (known as OB stars) will emit intense ultraviolet radiation, which steadily ionizes the surrounding gas of the giant molecular cloud, forming an H II region.

Also, because runaway stars are believed to be caused by supernovae, there is strong evidence that OB stars μ Columbae, AE Aurigae and 53 Arietis all originated from such explosions in Ori OB1 2.2, 2.7 and 4.9 million years ago.