A pre-main-sequence star (also known as a PMS star and PMS object) is a star in the stage when it has not yet reached the main sequence. Earlier in its...

In astronomy, the main sequence is a classification of stars which appear on plots of stellar color versus brightness as a continuous and distinctive...

G-type main-sequence star (yellow dwarf or G dwarf) is a main-sequence star of spectral type G. The spectral luminosity class is typically V. Such a star has...

An A-type main-sequence star (A dwarf) is a main-sequence (hydrogen burning) star of spectral type A. The spectral luminosity class is typically V. These...

A K-type main-sequence star (K-type dwarf or orange dwarf) is a main-sequence (hydrogen-burning) star of spectral type K. The luminosity class is typically...

An F-type main-sequence star is a main-sequence, hydrogen-fusing star of spectral type F. Such stars will generally have a luminosity class of V. They...

Hypergiants absolute magni- tude (MV) A B-type main-sequence star is a main-sequence (hydrogen-burning) star of spectral type B. The spectral luminosity...

in the pre-main-sequence phase of stellar evolution. It ends when a star of 0.5 M☉ or larger develops a radiative zone, or when a smaller star commences...

Hypergiants absolute magni- tude (MV) An O-type main-sequence star is a main-sequence—core hydrogen-burning—star of spectral type O. The spectral luminosity...

showed that the pre-main-sequence star can remain in radiative equilibrium throughout some period of its contraction to the main sequence. The Henyey track...

red dwarf is the smallest kind of star on the main sequence. Red dwarfs are by far the most common type of fusing star in the Milky Way, at least in the...

infalling gas is depleted, leaving a pre-main-sequence star, which contracts to later become a main-sequence star at the onset of hydrogen fusion producing...

A Herbig Ae/Be star (HAeBe) is a pre-main-sequence star – a young (<10 Myr) star of spectral types A or B. These stars are still embedded in gas-dust...

In stellar evolution, an FU Orionis star (also FU Orionis object, or FUor) is a pre–main-sequence star which displays an extreme change in magnitude and...

205117205.01) is a very young super-Neptune exoplanet, orbiting the pre-main-sequence star K2-33. It was discovered by NASA's Kepler space telescope on its...

Star formation Object classes Interstellar medium Molecular cloud Bok globule Dark nebula Young stellar object Protostar Pre-main-sequence star T Tauri...

accretion of gas and dust from the molecular cloud, becoming a pre-main-sequence star as it reaches its final mass. Further development is determined...

monitoring of a pharmaceutical drug or device Pre-main-sequence star, a star that has not yet reached the main sequence Phelan-McDermid Syndrome, a rare genetic...

a pre-main sequence star of spectral type B8 to A0 located 353 light-years (108 parsecs) from Earth in the southern constellation of Musca. The star is...

Myr A-class pre-main-sequence star HD 95086. It is roughly 5 times as massive as Jupiter and orbits about 70 AU away from the parent star. It was detected...

may be a main sequence star with a stellar class of B2. In 2007, a third companion was announced, which may be a low mass, pre-main sequence star. The X-ray...

K2-33 is an extremely young pre-main-sequence star located about 453 light-years (139 pc) away from the Earth in the constellation of Scorpius. It is known...

fan-shaped nebula opens from the star R Coronae Australis toward the star T CrA to the south-east. R CrA is a pre-main-sequence star in the Corona Australis molecular...

first identified as a pre-main-sequence star (PMS star) with the Gaia satellite. Without this prior identification as a PMS star the exoplanet signal of...

HD 95086, formally named Aiolos, is a pre-main-sequence star about 282 light-years (86 parsecs) away. Its surface temperature is 7,750±250 K. HD 95086...

PZ99 J160930.3−210459) is a pre-main-sequence star approximately 450 light-years away in the constellation of Scorpius. The star was identified as a member...

EPIC 204278916 is a pre-main-sequence star, about five million years old with a spectral type of M1, implying a red dwarf. It is part of the Upper Scorpius...

known as 1SWASP J140747.93−394542.6 or simply J1407, is a young, pre-main-sequence star that was eclipsed by the likely free-floating substellar object...

the end of their main sequence lifetime. Higher density regions of the interstellar medium form clouds, or diffuse nebulae, where star formation takes...

that occurs when the surface of a star or a planet cools. The cooling causes the internal pressure to drop, and the star or planet shrinks as a result. This...