HD 148427, formally named Timir, is a 7th-

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

K-type

subgiant A subgiant is a star that is brighter than a normal main-sequence star of the same spectral class, but not as bright as giant stars. The term subgiant is applied both to a particular spectral luminosity class and to a stage in the evolution ...

star A star is a luminous spheroid of plasma (physics), plasma held together by Self-gravitation, self-gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sk ...

approximately 230

light year A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distance, astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by t ...

s away in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The first constellati ...

Ophiuchus Ophiuchus () is a large constellation straddling the celestial equator. Its name comes from the Ancient Greek (), meaning "serpent-bearer", and it is commonly represented as a man grasping a snake. The serpent is represented by the constellati ...

. Its mass is 45% greater than the Sun, and it is three times the size and six times more luminous, although its age is 2½ billion years.

Brown dwarf/red dwarf companion

In August 2009, it was found to have a companion in orbit (HD 148427 b or Tondra) with a

minimum mass In astronomy, minimum mass is the lower-bound calculated mass of observed objects such as planets, stars, binary systems, nebulae, and black holes. Minimum mass is a widely cited statistic for extrasolar planets detected by the radial velocit ...

of and an orbital period of 331.5 days. In 2020, this object's

inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Eart ...

was measured, revealing its true mass to be between . This makes it either a

brown dwarf Brown dwarfs are substellar objects that have more mass than the biggest gas giant planets, but less than the least massive main sequence, main-sequence stars. Their mass is approximately 13 to 80 Jupiter mass, times that of Jupiter ()not big en ...

or a low-mass

red dwarf A 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 neighborhood of the Sun. However, due to their low luminosity, individual red dwarfs are ...

star.

Naming

HD 148427, and HD 148427 b (thought at the time to be an

exoplanet An exoplanet or extrasolar planet is a planet outside the Solar System. The first confirmed detection of an exoplanet was in 1992 around a pulsar, and the first detection around a main-sequence star was in 1995. A different planet, first det ...

), were chosen as part of the 2019

NameExoWorlds NameExoWorlds (also known as IAU NameExoWorlds) were various projects managed by the International Astronomical Union (I.A.U.) to encourage names to be submitted for astronomical objects, notably exoplanets. The accepted names would later be cons ...

campaign organised by the

International Astronomical Union The International Astronomical Union (IAU; , UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and developmen ...

, which assigned each country a star and planet to be named. HD 148427 was assigned to

Bangladesh Bangladesh, officially the People's Republic of Bangladesh, is a country in South Asia. It is the List of countries and dependencies by population, eighth-most populous country in the world and among the List of countries and dependencies by ...

. The winning name for the star was ''Timir'' meaning ''darkness'' in the

Bengali language Bengali, also known by its endonym and exonym, endonym Bangla (, , ), is an Indo-Aryan languages, Indo-Aryan language belonging to the Indo-Iranian languages, Indo-Iranian branch of the Indo-European languages, Indo-European language family. ...

, alluding to the star being far away in the darkness of space. The winning name for the companion was ''Tondra'' meaning ''nap'' in the Bengali language, alluding to the symbolic notion that the object was asleep until discovered.

References

{{DEFAULTSORT:HD 148427 K-type subgiants 148427 080687 Ophiuchus Durchmusterung objects Timir Binary stars M-type main-sequence stars

Brown dwarf/red dwarf companion

Naming

See also

References