equatorial Equatorial may refer to something related to:
*Earth's equator
**the tropics, the Earth's equatorial region
**tropical climate
*the Celestial equator
** equatorial orbit
**equatorial coordinate system
** equatorial mount, of telescopes
* equatorial ...
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 origins of the e ...
of Cetus. It is dimly visible to the naked eye with a combined apparent visual magnitude of 5.20. The system is located at a distance of approximately 69
light year
A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...
stellar parallax
Stellar parallax is the apparent shift of position of any nearby star (or other object) against the background of distant objects, and a basis for determining (through trigonometry) the distance of the object. Created by the different orbital p ...
, and is drifting further away with a
radial velocity
The radial velocity or line-of-sight velocity, also known as radial speed or range rate, of a target with respect to an observer is the temporal rate of change, rate of change of the distance or Slant range, range between the two points. It is e ...
of +10.4 km/s. It shares a common motion with the Hyades moving group, although it is too old to be a member.
This star was identified as a visual binary system by G. W. Hough in 1844 and given the identifier HO 212. The pair have an
orbital period
The orbital period (also revolution period) is the amount of time a given astronomical object takes to complete one orbit around another object. In astronomy, it usually applies to planets or asteroids orbiting the Sun, moons orbiting planets ...
stellar classification
In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction grati ...
of F6 V and a visual magnitude of 5.61. It appears to have an active chromosphere and is classified as an
RS Canum Venaticorum variable An RS Canum Venaticorum variable is a type of variable star. The variable type consists of close binary stars having active chromospheres which can cause large stellar spots. These spots are believed to cause variations in their observed luminosity. ...
with a
variable star designation
In astronomy, a variable star designation is a unique identifier given to variable stars. It uses a variation on the Bayer designation format, with an identifying label (as described below) preceding the Latin genitive of the name of the constell ...
of BU Cet. The star was detected as a source of soft
X-ray emission
Astrophysical X-ray sources are astronomical objects with physical properties which result in the emission of X-rays.
Several types of astrophysical objects emit X-rays. They include galaxy clusters, black holes in active galactic nuclei (AGN), ...
by EXOSAT. It has 18% more mass than the Sun and is estimated to be about four billion years old.
In 1907, E. B. Frost discovered the primary is a
spectroscopic binary
A binary star is a system of two star, stars that are gravity, 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 using a telescope as separa ...
, making this a triple star system. This is a double-lined spectroscopic binary with a period of 2.1 days and a circularized orbit. The companion signature was confirmed using the separated fringe packet technique with the CHARA array. It is most likely a
K-type main-sequence star
A K-type main-sequence star, also referred to as a K-type dwarf or an orange dwarf, is a main-sequence (hydrogen-burning) star of spectral type K and luminosity class V. These stars are intermediate in size between red M-type main-sequence stars ...
with a class of K3.5 V and 70% of the mass of the Sun.
The secondary member of the visual binary, designated component B, is a
G-type main-sequence star
A G-type main-sequence star (Spectral type: G-V), also often, and imprecisely called a yellow dwarf, or G star, is a main-sequence star (luminosity class V) of spectral type G. Such a star has about 0.9 to 1.1 solar masses and an effective temp ...
with a class of G4 V. It has 90% of the Sun's mass and a visual magnitude of 6.90. A distant visual companion to this system was detected by
S. W. Burnham
Sherburne Wesley Burnham (December 12, 1838 – March 11, 1921) was an American astronomer.
For more than 50 years Burnham spent all his free time observing the heavens, mainly concerning himself with binary stars.
Biography
Sherburne ...
in 1877. Designated component C, this star is a background object of magnitude 12.50. As of 1999, it was located at an
angular separation
Angular distance \theta (also known as angular separation, apparent distance, or apparent separation) is the angle between the two sightlines, or between two point objects as viewed from an observer.
Angular distance appears in mathematics (in pa ...
0142
Fourteen or 14 may refer to:
* 14 (number), the natural number following 13 and preceding 15
* one of the years 14 BC, AD 14, 1914, 2014
Music
* 14th (band), a British electronic music duo
* ''14'' (David Garrett album), 2013
*''14'', an unrel ...