Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Orion |
Right ascension | 05h 36m 25.43205s [1] |
Declination | –06° 42′ 57.6847″ [1] |
Apparent magnitude (V) | 10.2–10.7 [2] |
Characteristics | |
Spectral type | A1e [3] |
Variable type | Orion variable [4] |
Astrometry | |
Radial velocity (Rv) | 15.40 [5] km/s |
Proper motion (μ) | RA: –0.667 [1] mas/yr Dec.: –2.408 [1] mas/yr |
Parallax (π) | 2.6425 ± 0.1117 mas [1] |
Distance | 1,230 ± 50 ly (380 ± 20 pc) |
Orbit [6] | |
Period (P) | 104 ± 5 days |
Semi-amplitude (K1) (primary) | < 1.4 km/s |
Semi-amplitude (K2) (secondary) | 18 ± 14 km/s |
Details [6] | |
Primary | |
Mass | 2.87 M☉ |
Radius | 3 R☉ |
Luminosity | 100 L☉ |
Temperature | 10,500 ± 500 K |
Metallicity [Fe/H] | 0.5 dex |
Rotation | 4.31276 days |
Rotational velocity (v sin i) | 6.7 ± 1.1 km/s |
Secondary | |
Mass | 1.6 M☉ |
Radius | 2 R☉ |
Luminosity | 3.16 L☉ |
Temperature | 5,500 ± 500 K |
Rotational velocity (v sin i) | 18.7 ± 3.2 km/s |
Age | 2 ± 1 million Myr |
Other designations | |
Database references | |
SIMBAD | data |
V380 Ori is a young multiple star system located near the Orion Nebula in the constellation Orion, thought to be somewhere between 1 and 3 million years old. It lies at the centre of NGC 1999 and is the primary source lighting up this and other nebulae in the region.
V380 Orionis is a multiple star system containing at least three stars. A very faint cool star 9" away is also thought to be gravitationally bound, making it a hierarchical quadruple system. Two infrared sources within NGC 1999 have been listed as companions in some catalogues, [7] but are not thought to be stars. [8] When discovered, they were referred to as V380 Ori-B and V-380 Ori-C, [9] a notation which can lead to confusion. [8]
The main component is visible as the 10th magnitude variable star at the centre of NGC 1999, referred to as the primary. Speckle interferometry shows a cool companion separated by 0.15", approximately 62 AU, referred to as the tertiary. Spectroscopy shows a third star at a projected separation less than 0.33 AU, referred to as the secondary. The two closest stars, the primary and tertiary, are surrounded by a circumstellar disk, lying almost edge-on to observers on earth. The fourth star has a projected separation of 4,000 AU and is receding from the other three. [8]
The system is believed to have formed with all four stars close together, but interacted to eject the smallest star into an unstable but gravitationally bound orbit around 20,000 years ago. [8]
The primary and secondary, the two closest stars, are calculated to orbit every 104 days. The radial velocity signatures in the spectrum have a large margin of uncertainty and the orbit is poorly defined. Comparing the mass ratio found from the orbit with masses assumed from other physical properties suggests that the orbit is seen close to pole-on. [6]
The primary star is a hot white Herbig Ae/Be star that has been variously assigned spectral types between B9 and A1. It has a surface temperature of 10,500 ± 500 K, is around 2.87 times as massive as the sun, 3 times its radius, and 100 times as luminous. It has a strong magnetic field which varies every 4.1 days and this is assumed to be the star's rotation period. Models show that the axis of rotation is inclined at 32 degrees. [6] It is a variable star, considered an Orion variable, with occasional fading and other variability caused by obscuration from the surrounding dust. The apparent magnitude varies irregularly between 10.2 and 10.7. [2] The properties of the star are calculated based on its maximum brightness, assumed to be the least obscured. [6]
The secondary is a T Tauri star, detected by distinctive spectral lines that could not be produced by the hotter primary star, that has a surface temperature of 5,500 ± 500 K, is around 1.6 times as massive as the sun, twice its radius, and three times as luminous. [6]
The nature of the tertiary component is uncertain. No spectral lines have been seen originating from this component. [6]
The fourth star, sometimes called V380 Orionis B, is a small, cool object of spectral type M5 or M6 that is either a red dwarf or brown dwarf. [8]
One of the component stars of V380 Orionis appears to have launched a polar jet that helped to clear the keyhole-shaped hole in the surrounding nebula known as NGC 1999. [11] The system is surrounded by a bow shock—the total structure over 17 light-years (5.3 parsecs) across. [8]
Mintaka, designation Delta Orionis and 34 Orionis, is a multiple star system some 1,200 light-years from the Sun in the constellation of Orion. Together with Alnitak and Alnilam, the three stars form Orion's Belt, known by many names among ancient cultures. The star is located very close to the celestial equator. When Orion is near the meridian, Mintaka is the rightmost of the Belt's stars when viewed from the Northern Hemisphere facing south.
Iota Orionis is a multiple star system in the equatorial constellation of Orion the hunter. It is the eighth-brightest member of Orion with an apparent visual magnitude of 2.77 and also the brightest member of the asterism known as Orion's Sword. It is a member of the NGC 1980 open cluster. From parallax measurements, it is located at a distance of roughly 1,340 light-years from the Sun.
Chi1 Orionis is a star about 28 light years away. It is in the constellation Orion, where it can be seen in the tip of the hunter's upraised club.
36 Ophiuchi is a triple star system 19.5 light-years from Earth. It is in the constellation Ophiuchus.
R Monocerotis, abbreviated R Mon, is a very young binary star system in the equatorial constellation of Monoceros. The apparent magnitude of R Mon varies between 10 and 12 and the spectral type is B8IIIe.
Sigma Orionis or Sigma Ori is a multiple star system in the constellation Orion, consisting of the brightest members of a young open cluster. It is found at the eastern end of the belt, south west of Alnitak and west of the Horsehead Nebula which it partially illuminates. The combined brightness of the component stars is magnitude 3.80.
HD 37017 is a binary star system in the equatorial constellation of Orion. It has the variable star designation 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 years based on parallax, and is drifting further away with a radial velocity of +32 km/s. The system is part of star cluster NGC 1981.
V1057 Cygni is a suspected binary star system in the northern constellation of Cygnus. It is a variable star of the FU Orionis-type, and was the second FU Orionis-type variable to be discovered. The system is located at a distance of approximately 3,000 light years from the Sun, in the North America Nebula. It has an apparent visual magnitude of around 12.4.
25 Orionis, less commonly known by its Bayer designation Psi1 Orionis is a fifth-magnitude star in the constellation Orion. It lies among a dense cluster of low-mass pre-main-sequence stars in the Orion OB1a.
Sigma Ophiuchi, Latinized from σ Ophiuchi, is a single, orange-hued star in the equatorial constellation Ophiuchus. Its apparent visual magnitude is 4.31, which is bright enough to be faintly visible to the naked eye. The annual parallax shift of 3.62 mas as seen from Earth provides a distance estimate of roughly 900 light years. It is moving closer to the Sun with a radial velocity of −28 km/s.
Theta1 Orionis A is a variable trinary star in the constellation Orion. Its apparent magnitude range is 6.72 to 7.65 with a period of 65.432 days. It is one of the main stars in The Trapezium in Orion, along with B, C, and D, as well as the fainter E.
Theta2 Orionis is a multiple star system in the constellation Orion. It is a few arc minutes from its more famous neighbour the Trapezium Cluster, also known as θ1 Orionis.
QZ Puppis is a class B2.5V star in the constellation Puppis. Its apparent magnitude is 4.5 and it is approximately 650 light years away based on parallax.
HD 259431 is a young stellar object in the constellation of Monoceros.
Theta1 Orionis B, also known as BM Orionis, is a multiple star system containing at least five members. It is also one of the main stars of the Trapezium Cluster, with the others being A, C, and D. The primary is an eclipsing variable and one of the youngest known eclipsing binary systems.
WR 12 is a spectroscopic binary in the constellation Vela. It is an eclipsing binary consisting of a Wolf-Rayet star and a luminous companion of unknown spectral type. The primary is one of the most luminous stars known.
GW Orionis is a T Tauri type pre-main sequence hierarchical triple star system. It is associated with the Lambda Orionis star-forming region and has an extended circumtrinary protoplanetary disk.
HD 150193 is a binary star system in the constellation of Ophiuchus. The primary star was identified as a Herbig Ae/Be star with a strong solar wind, losing approximately a tenth of solar mass per million years. It does host a very small debris disk, likely due to disk truncation by the nearby stellar companion. The disk is inclined 38±9° to the plane of sky. It appears to be highly evolved and asymmetric, with indications of flattening and grains growth.
BF Orionis is a young Herbig Ae/Be star in the constellation of Orion about 1250 light years away, within the Orion Nebula. It is the most massive star of the small birth cluster of four stars.
CQ Tauri is a young variable star in the equatorial constellation of Taurus. It is too faint to be visible to the naked eye with an apparent visual magnitude that ranges from 8.7 to 12.25. The distance to this star is approximately 487 light years based on parallax measurements, and it is drifting further away with a radial velocity of ~23 km/s. It appears to be part of the T-association Tau 4. CQ Tauri lies close enough to the ecliptic to undergo lunar occultations.