HD 136118
Encyclopedia
HD 136118 is a F-type main-sequence star
located approximately 171 light-year
s away in the constellation
of Serpens Cauda. It is an F-type dwarf
and has apparent magnitude
+6.94.
discovered a very massive planet
, which was announced on February 7, 2002. On November 25, 2009, the object turned out to be a brown dwarf
.
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...
located approximately 171 light-year
Light-year
A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...
s away in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
of Serpens Cauda. It is an F-type dwarf
Yellow-white dwarf
An F-type main-sequence star is a main-sequence, hydrogen-fusing star of spectral type F and luminosity class V. These stars have from 1.0 to 1.4 times the mass of the Sun and surface temperatures between 6,000 and 7,600 K., Tables VII and VIII. This temperature range gives the F-type stars a...
and has apparent magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
+6.94.
Brown dwarf companion
The astronomer Debra FischerDebra Fischer
Debra A. Fischer is a professor of astronomy at Yale University. Fischer has co-authored over 100 papers on dwarf and sub-stellar mass objects in the galactic neighborhood, including many on extrasolar planets. She is a principal investigator with the N2K Consortium searching for exoplanets...
discovered a very massive planet
Extrasolar planet
An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of such planets have been identified as of . It is now known that a substantial fraction of stars have planets, including perhaps half of all Sun-like stars...
, which was announced on February 7, 2002. On November 25, 2009, the object turned out to be a brown dwarf
Brown dwarf
Brown dwarfs are sub-stellar objects which are too low in mass to sustain hydrogen-1 fusion reactions in their cores, which is characteristic of stars on the main sequence. Brown dwarfs have fully convective surfaces and interiors, with no chemical differentiation by depth...
.