Ross 154 is a red dwarf

Red dwarf

According to the Hertzsprung-Russell diagram, a red dwarf star is a small and relatively cool star, of the main sequence, either late K or M spectral type....

 star

Star

A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...

 approximately 3.0 pc

Parsec

The parsec is a unit of length used in astronomy. It is about 3.26 light-years, or just under 31 trillion kilometres ....

 or 9.68 light years from the Sun

Sun

The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...

. It is the nearest star in the southern constellation Sagittarius

Sagittarius (constellation)

Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...

, and one of the closest to the Sun. Its nearest neighbor is Barnard's star

Barnard's star

Barnard's Star, also known occasionally as Barnard's "Runaway" Star, is a very low-mass red dwarf star approximately six light-years away from Earth in the constellation of Ophiuchus . In 1916, the American astronomer E.E...

, located 1.66 pc (5.41 ly) away.

This star was first catalogued by Frank Elmore Ross

Frank Elmore Ross

Frank Elmore Ross was an American astronomer and physicist. He was born in San Francisco, California and died in Altadena, California. In 1901 he received his doctorate from the University of California. In 1905 he became director of the International Latitude Observatory station at Gaithersburg,...

 in 1925, and formed part of his fourth list of new variable stars. It was found to be a UV Ceti-type flare star

Flare star

A flare star is a variable star that can undergo unpredictable dramatic increases in brightness for a few minutes. It is believed that the flares on flare stars are analogous to solar flares in that they are due to magnetic reconnection in the atmospheres of the stars. The brightness increase is...

, with a mean time between major flares of about two days.