triple star
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 ''sta ...
system in the northern
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 ...
naked eye
Naked eye, also called bare eye or unaided eye, is the practice of engaging in visual perception unaided by a magnification, magnifying, Optical telescope#Light-gathering power, light-collecting optical instrument, such as a telescope or microsc ...
about 2.5° east-northeast of the
open cluster
An open cluster is a type of star cluster made of tens to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way galaxy, and ...
apparent visual magnitude
Apparent magnitude () is a measure of the 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 of the object's light ca ...
of 4.24. Based upon an annual parallax shift of 2.95 mas, it is located at a distance of roughly 1,100
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 from the
Sun
The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...
.
The inner pair of stars in this system form a single-lined
spectroscopic binary
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 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 ...
of 72.0162 days and an
eccentricity
Eccentricity or eccentric may refer to:
* Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal"
Mathematics, science and technology Mathematics
* Off-Centre (geometry), center, in geometry
* Eccentricity (g ...
giant star
A giant star has a substantially larger radius and luminosity than a main-sequence (or ''dwarf'') star of the same surface temperature. They lie above the main sequence (luminosity class V in the Yerkes spectral classification) on the Hertzsp ...
with a
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 gratin ...
of B2.5 III. It is a
Beta Cephei variable
Beta Cephei variables, also known as Beta Canis Majoris stars, are variable stars that exhibit small rapid variations in their brightness due to pulsations of the stars' surfaces, thought due to the unusual properties of iron at temperatures of 200 ...
with an estimated 8.4 times the
mass of the Sun
The solar mass () is a frequently used unit of mass in astronomy, equal to approximately . It is approximately equal to the mass of the Sun. It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies a ...
and around 7.1 times the
Sun's radius
Solar radius is a unit of distance used to express the size of objects in astronomy relative to the Sun. The solar radius is usually defined as the radius to the layer in the Sun's photosphere where the optical depth equals 2/3:
1\,R_ = 6.957\ti ...
. The star is roughly 33 million years old and is spinning with a
projected rotational velocity
Stellar rotation is the angular motion of a star about its axis. The rate of rotation can be measured from the spectrum of the star, or by timing the movements of active features on the surface.
The rotation of a star produces an equatorial bu ...
of 50 km/s. It is radiating 8,442 times the
solar luminosity
The solar luminosity () is a unit of radiant flux (Power (physics), power emitted in the form of photons) conventionally used by astronomers to measure the luminosity of stars, galaxy, galaxies and other celestial objects in terms of the output of ...
effective temperature
The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of electromagnetic radiation. Effective temperature is often used as an estimate of a body's surface temperature ...
of around 20,815 K.
The third member of this system is a magnitude 5.98 star at an
angular separation
Angular distance or angular separation is the measure of the angle between the orientation of two straight lines, rays, or vectors in three-dimensional space, or the central angle subtended by the radii through two points on a sphere. When t ...
of 0.10
arc second
A minute of arc, arcminute (abbreviated as arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of a degree. Since one degree is of a turn, or complete rotation, one arcminute is of a tu ...
s along a
position angle
In astronomy, position angle (usually abbreviated PA) is the convention for measuring angles on the sky. The International Astronomical Union defines it as the angle measured relative to the Celestial pole, north celestial pole (NCP), turning pos ...
of 129°, as of 1996.
Historical names
In
Chinese
Chinese may refer to:
* Something related to China
* Chinese people, people identified with China, through nationality, citizenship, and/or ethnicity
**Han Chinese, East Asian ethnic group native to China.
**'' Zhonghua minzu'', the supra-ethnic ...
4 Lacertae
4 Lacertae is a single blue supergiant star in the northern constellation Lacerta, located about 2,600 light years away. This object visible to the naked eye as a white-hued star with an apparent visual magnitude of 4.55. It is moving ...
HD 206267
HD 206267A is a hierarchical triple star system in the northern circumpolar constellation of Cepheus. Two of the members form a spectroscopic binary that orbit each other with a period of 3.7 days, while a third member lies further awa ...
,
ε Cephei
Epsilon Cephei, Latinized from ε Cephei, is a star in the northern constellation of Cepheus. Based upon an annual parallax shift of 38.17 mas as seen from the Earth, it is located about 85 light years from the Sun. The star ...
AR Cassiopeiae
AR Cassiopeiae (AR Cas) is a variable star in the constellation of Cassiopeia (constellation), Cassiopeia. It is thought to be a member of a multiple star system, septuple star system, one of only two known star systems with a multipl ...
3 Andromedae
3 Andromedae, abbreviated 3 And, is a single star in the northern constellation of Andromeda. ''3 Andromedae'' is the Flamsteed designation. It is visible to the naked eye with an apparent visual magnitude of 4.64. The distance to this ...
,
7 Andromedae
7 Andromedae, also named Honores, is a single, yellow-white hued star in the northern constellation of Andromeda. ''7 Andromedae'' is the Flamsteed designation, abbreviated 7 And. It is visible to the naked eye with an apparent visual m ...
Chinese name
Chinese may refer to:
* Something related to China
* Chinese people, people identified with China, through nationality, citizenship, and/or ethnicity
**Han Chinese, East Asian ethnic group native to China.
**'' Zhonghua minzu'', the supra-ethni ...