HD 37017 is a

binary star A binary star 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 using a telescope as separate stars, in wh ...

system in the

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 Orion. It has the

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 ...

V1046 Orionis; ''HD 37017'' is the identifier from the '' Henry Draper Catalogue''. The system is a challenge to view with the naked eye, being close to the lower limit of visibility with a combined apparent visual magnitude of 6.55. It is located at a distance of approximately 1,230

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 ...

s based on

parallax Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby objects ...

, 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 +32 km/s. The system is part of star cluster

NGC 1981 NGC 1981 (also known as OCL 525) is an open cluster which is located in the constellation Orion. It was discovered by John Herschel on 4 January 1827. Its apparent magnitude is 4.2 and its size is 28.00 arc minutes. It lies to the north of t ...

. The binary nature of this system was suggested by A. Blaauw and T. S. van Albada in 1963. It is a double-lined

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 ...

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 18.6556 days and an eccentricity of 0.31. The eccentricity is considered unusually large for such a close system. It forms a suspected

eclipsing binary A binary star 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 using a telescope as separate stars, in wh ...

that ranges in brightness from 6.54 down to 6.58. The primary is a helium-strong, magnetic chemically peculiar star 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 grati ...

of B1.5 Vp. It has a magnetic field strength of , and the helium concentrations are located at the magnetic poles. V1046 Orionis was found to be a variable star by L. A. Balona in 1997, and is now classified as an

SX Arietis variable SX Arietis variables are a class of variable stars. They are generally B-type main sequence stars of spectral types B0p to B9p— high-temperature analogues of Alpha2 Canum Venaticorum variables—and exhibit strong magnetic fields and intense He& ...

. The star undergoes periodic changes in visual brightness,

magnetic field A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular to its own velocity and to ...

strength, and

spectral ''Spectral'' is a 2016 3D military science fiction, supernatural horror fantasy and action-adventure thriller war film directed by Nic Mathieu. Written by himself, Ian Fried, and George Nolfi from a story by Fried and Mathieu. The film stars J ...

characteristics with a cycle time of 0.901175 days – the star's presumed

rotation period The rotation period of a celestial object (e.g., star, gas giant, planet, moon, asteroid) may refer to its sidereal rotation period, i.e. the time that the object takes to complete a single revolution around its axis of rotation relative to the ...

. Radio emission has been detected that varies with the rotation period. The secondary component has an estimated 4.5 times the

mass of the Sun The solar mass () is a standard unit of mass in astronomy, equal to approximately . It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies and black holes. It is approximately equal to the mass ...

. The class has been estimated as type B6III-IV.

References

External links

Simbad
{{Stars of Orion B-type main-sequence stars Ap stars SX Arietis variables Eclipsing binaries Spectroscopic binaries Orion (constellation) Durchmusterung objects 037017

1890 Events January–March * January 1 ** The Kingdom of Italy establishes Eritrea as its colony, in the Horn of Africa. ** In Michigan, the wooden steamer ''Mackinaw'' burns in a fire on the Black River. * January 2 ** The steamship ...

026233 Orionis, V1046