Observation data Epoch J2000 Equinox | |
---|---|
Constellation | Orion |
Right ascension | 05h 33m 31.44649s [1] |
Declination | −01° 09′ 21.8595″ [1] |
Apparent magnitude (V) | 5.31 (- 5.55) - 5.66 [2] |
Characteristics | |
Evolutionary stage | B1V + B7V [3] |
U−B color index | −0.09 [4] |
B−V color index | −0.18 [4] |
Variable type | Eclipsing, [5] β Cephei [3] |
Astrometry | |
Radial velocity (Rv) | 22.2 [6] km/s |
Proper motion (μ) | RA: −1.088 [1] mas/yr Dec.: −1.183 [1] mas/yr |
Parallax (π) | 2.2654 ± 0.1138 mas [1] |
Distance | 1,210 ± 39 ly (371 ± 12 [3] pc) |
Absolute bolometric magnitude (Mbol) | −5.36 + −1.65 [3] |
Orbit [3] | |
Period (P) | 1.4853784 days |
Semi-major axis (a) | 13.51 R☉ |
Eccentricity (e) | 0 |
Inclination (i) | 78.28° |
Details [3] | |
VV Ori A | |
Mass | 9.52 M☉ |
Radius | 4.958 R☉ |
Luminosity | 10,400 L☉ |
Surface gravity (log g) | 4.026 cgs |
Temperature | 26,200 K |
VV Ori B | |
Mass | 3.80 M☉ |
Radius | 2.360 R☉ |
Luminosity | 339 L☉ |
Surface gravity (log g) | 4.272 cgs |
Temperature | 16,100 K |
Other designations | |
Database references | |
SIMBAD | data |
VV Orionis is an eclipsing binary located in the belt region of the constellation Orion. It is a faint naked eye star.
The brightness of VV Orionis dips regularly every 18 hours. The peak visual magnitude is 5.3, which varies slowly in between the dips. The minimum brightness of the dips alternates between magnitude 5.55 and 5.66. The deep minima have a somewhat rounded bottom, while the less deep minima have flat bottoms with a constant magnitude for several hours. [5] However, there are also additional cycles in the lightcurve that suggest that at least one of the stars is pulsating. [3]
The VV Orionis system contains two stars which are very close but are not touching. Their orbit is aligned almost perpendicularly to us and there are both primary and secondary eclipses. During secondary eclipse, the primary transits against the secondary, which produces the flat bottom to the secondary minimum. The orbital alignment allows very precise calculation of the orbit and the properties of the stars, but results from different studies have been unusually inconsistent. The lack of a single consistent solution to the orbit has led to suggestions that there is a third star in the system, [8] but this is unproven. A circular orbit with the stars only 13.5 R☉ apart can account for the observed brightness and radial velocity changes, [5] while a third body may explain the decreasing orbital inclination. [3]
The two stars are both on the main sequence. The primary, a β Cephei pulsator, has a spectral type of B1 and temperature of about 26,000 K, while the secondary (possibly a slowly pulsating B-type star) has a spectral type of B7 and a temperature of about 16,000 K. The secondary has a mass of 3.8 M☉, radius of 2.4 R☉, and bolometric luminosity of 340 L☉. The primary is over twice the mass, twice the radius, and thirty times the luminosity of its companion. [3]
W Sagittarii is a multiple star system star in the constellation Sagittarius, and a Cepheid variable star.
Tau Canis Majoris is a multiple star system in the constellation Canis Major. It is approximately 5,000 light years distant from Earth and is the brightest member of the open cluster NGC 2362.
UW Canis Majoris is a star in the constellation Canis Major. It is classified as a Beta Lyrae eclipsing contact binary and given the variable star designation UW Canis Majoris. Its brightness varies from magnitude +4.84 to +5.33 with a period of 4.39 days. Bode had initially labelled it as Tau2 Canis Majoris, but this designation had been dropped by Gould and subsequent authors.
Beta Cephei is a triple star system of the third magnitude in the constellation of Cepheus. Based on parallax measurements obtained during the Hipparcos mission, it is approximately 690 light-years distant from the Sun. It is the prototype of the Beta Cephei variable stars.
VV Cephei, also known as HD 208816, is an eclipsing binary star system located in the constellation Cepheus. It is both a B[e] star and shell star.
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22 Vulpeculae is a binary star system in the northern constellation Vulpecula. Based on its parallax, it is located some 1,490 light-years away, and it has an apparent magnitude of about 5.2, making it visible to the naked eye. The system is moving closer to the Earth with a heliocentric radial velocity of −23 km/s.
V381 Cephei is a triple star system in the northern constellation of Cepheus. Its apparent magnitude is slightly variable between 5.5 and 5.7.
1 Persei is an eclipsing binary star in the constellation Perseus. Its uneclipsed apparent magnitude is 5.49. The binary star consists of two B2 type main-sequence stars in a 25.9 day eccentric orbit. The stars are surrounded by a faint cloud of gas visible in mid-infrared, although whether they are the origin of the gas or simply passing through it is unclear.
22 Orionis is a binary star in the equatorial constellation of Orion. It has the Bayer designation o Orionis, while 22 Orionis is the Flamsteed designation. This system is visible to the naked eye as a faint, blue-white hued star with an apparent visual magnitude of 4.74. It is located approximately 1,100 light years away from the Sun based on parallax. The system is moving further from the Earth with a heliocentric radial velocity of +28.80
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.
KQ Puppis is a spectroscopic binary located about 2,700 light-years from Earth in the constellation Puppis. A red supergiant star and a B-type main-sequence star orbit each other every 27 years. Its apparent magnitude varies between 4.82 and 5.17, making it faintly visible to the naked eye.
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AC Herculis, is an RV Tauri variable and spectroscopic binary star in the constellation of Hercules. It varies in brightness between apparent magnitudes 6.85 and 9.0.
Psi2 Orionis a binary star system in the equatorial constellation of Orion. It has an apparent visual magnitude of 4.6, indicating that it is visible to the naked eye. Based upon an annual parallax shift of 2.87 mass, it is roughly 1,100 light years distant from the Sun.
HR 7484 is a binary star system in the northern constellation of Cygnus. It is dimly visible to the naked eye under good viewing conditions, having an apparent visual magnitude of 5.89. Based upon an annual parallax shift of 24.71, it is located 132 light years away. The system is moving closer with a heliocentric radial velocity of −14 km/s.
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.