126 Tauri (126 Tau) is a

triple star system A star system or stellar system is a small number of stars that orbit each other, bound by gravitational attraction. It may sometimes be used to refer to a single star. A large group of stars bound by gravitation is generally called a ''st ...

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 ...

Taurus Taurus is Latin for 'bull' and may refer to: * Taurus (astrology), the astrological sign ** Vṛṣabha, in vedic astrology * Taurus (constellation), one of the constellations of the zodiac * Taurus (mythology), one of two Greek mythological ch ...

, approximately 600

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. Its

apparent magnitude Apparent magnitude () is a measure of the Irradiance, brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction (astronomy), ...

is 4.83, making it visible to the naked eye with dark skies. 126 Tauri is a well-known

binary star A binary star or binary star system is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved as separate stars us ...

with the two components in an eccentric orbit of over a hundred years. The secondary, component B, has also shown

radial velocity The radial velocity or line-of-sight velocity of a target with respect to an observer is the rate of change of the vector displacement between the two points. It is formulated as the vector projection of the target-observer relative velocity ...

variations that indicate an unseen companion in a 4.77-day orbit. The combined spectral class is typically quoted as B3IV, occasionally B3V. The primary alone has been classed as B3V, although the two components have been individually measured at B8V and B7V.

References

{{DEFAULTSORT:126 Tauri Taurus (constellation) B-type subgiants Tauri, 126 Durchmusterung objects 037711 026777

1946 1946 (Roman numerals, MCMXLVI) was a common year starting on Tuesday of the Gregorian calendar, the 1946th year of the Common Era (CE) and ''Anno Domini'' (AD) designations, the 946th year of the 2nd millennium, the 46th year of the 20th centur ...

Triple star systems B-type main-sequence stars