Visible, blue and ultraviolet light curves for an eclipse of V2291 Ophiuchi, adapted from Griffin et al. (1995) [1] | |
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Ophiuchus |
Right ascension | 18h 25m 38.799s [2] |
Declination | +08° 01′ 55.23″ [2] |
Apparent magnitude (V) | +5.64 [3] |
Characteristics | |
Spectral type | G9IIb / B8V |
Variable type | Zeta Aurigae-type |
Astrometry | |
Proper motion (μ) | RA: -4.07 ± 0.54 [2] mas/yr Dec.: -6.34 ± 0.31 [2] mas/yr |
Parallax (π) | 4.14 ± 0.41 mas [2] |
Distance | 790 ± 80 ly (240 ± 20 pc) |
Absolute magnitude (MV) | –1.33 [3] |
Details | |
Mass | 3.86/2.95 [4] M☉ |
Radius | 33/3 [4] R☉ |
Luminosity | 562/146 L☉ |
Temperature | 4900/11600 [4] K |
Orbit | |
Period (P) | 1.055 [4] yr |
Semi-major axis (a) | 1.96 [4] AU |
Eccentricity (e) | 0.311 [4] |
Inclination (i) | 87 [4] ° |
Other designations | |
Database references | |
SIMBAD | data |
HR 6902 (also designated V2291 Oph) is a binary system located 790 light years away [2] from the Sun in the Ophiuchus constellation. The system includes an orange bright giant star and a B-type main sequence star, forming an eclipsing binary of Zeta Aurigae type. The system is also surrounded by a warm circumstellar envelope and the spectra show silicon and carbon absorption up to a distance of 3.3 giant radii. [4]
Kappa Arae is the Bayer designation for a single star in the southern constellation of Ara. Based upon parallax measurements, it is approximately 460 light-years distant from Earth, give or take a 30 light-year margin of error. With an apparent visual magnitude of 5.21, this star is faintly visible to the naked eye.
Nu Aurigae, Latinised from ν Aurigae, is the Bayer designation for a star in the northern constellation of Auriga. It is visible to the naked eye with an apparent visual magnitude of 3.96 and is approximately 220 light-years distant from the Earth. This is an evolved giant star with a stellar classification of G9.5 III. It is a red clump star, which indicates that it is generating energy through the fusion of helium at its core. The outer envelope has expanded to 19 times the radius of the Sun and cooled to 4,571 K, giving it the characteristic yellow-hued glow of a G-type star. It shines with 135 times the luminosity of the Sun.
Tau Aurigae, Latinized from τ Aurigae, is a star in the northern constellation Auriga. It is visible to the naked eye with an apparent visual magnitude of 4.505, and is approximately 207 light-years distant from Earth.
Chi Aurigae, Latinized from χ Aurigae, is the Bayer designation for a binary star system in the northern constellation of Auriga. It is faintly visible to the naked eye with an apparent visual magnitude of 4.74. The annual parallax shift of this object is much smaller than the measurement error, making distance estimates by that means unreliable. The estimated distance to this star is approximately 3,000 light years. The brightness of the star is diminished by 1.26 in magnitude from extinction caused by intervening gas and dust.
2 Aurigae is a possible binary star system in the northern constellation of Auriga. This object is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of +4.79. It forms an attractive four-star asterism when viewed in a low power eyepiece, together with the nearby HIP 22647 and another very loose visual pair, HIP 22776 and HIP 22744, all above magnitude 8. 2 Aurigae is moving closer to the Earth with a heliocentric radial velocity of −17 km/s.
Sigma Aurigae, Latinized from σ Aurigae, is a giant star in the northern constellation of Auriga. It is faintly visible to the naked eye with an apparent visual magnitude of 4.99. With an annual parallax shift of 6.21 mas, it is approximately 530 light-years distant from the Earth. This is an evolved giant star with a stellar classification of K4 III.
Phi Aurigae, Latinized from φ Aurigae, is a giant star in the northern constellation of Auriga. It is faintly visible to the naked eye with an apparent visual magnitude of 5.089. It lies 10′ from another faint naked-eye star HD 35520, between the three open clusters M36 and M38, and NGC 1893.
40 Aurigae is a binary star in the constellation Auriga. Its apparent magnitude is 5.345, meaning it can just barely be seen with the naked eye. Based on parallax estimates made by the Hipparcos spacecraft, the system is located some 340 light-years away.
AR Aurigae, also known by its Flamsteed designation 17 Aurigae, is a binary star in the constellation Auriga. Based on parallax measurements made by the Hipparcos spacecraft, it is approximately 461 light-years from Earth.
Psi4 Aurigae, Latinized from ψ4 Aurigae, is a single, orange-hued star in the northern constellation of Auriga. It is visible to the naked eye with an apparent visual magnitude of +5.02. With an annual parallax shift of 10.08 ± 0.33 mas, it is approximately 324 light-years distant from Earth.
Psi5 Aurigae is a star in the northern constellation of Auriga. It is faintly visible to the naked eye with an apparent visual magnitude of 5.25. Based upon parallax measurements made during the Hipparcos mission, this star is approximately 53.9 light-years distant from Earth. There is an optical companion which is 36 arcseconds away and has an apparent magnitude of +8.4.
Psi6 Aurigae, Latinized from ψ6 Aurigae, is a spectroscopic binary star in the northern constellation of Auriga. It is a dim, naked eye star with an apparent visual magnitude of +5.22. Based upon a measured annual parallax shift of 9.05 ± 0.38 mas, it is approximately 360 light-years distant from the Earth.
Psi7 Aurigae, Latinized from ψ7 Aurigae, is a star in the northern constellation of Auriga. It is a dim, naked eye star with an apparent visual magnitude of 5.02. Based upon Gaia Data Release 2 parallax values, it is approximately 330 light-years from Earth.
Psi9 Aurigae, Latinised from ψ9 Aurigae, is a star in the northern constellation of Auriga. It is dimly visible to the naked eye with an apparent visual magnitude of 5.75. Based upon an annual parallax shift of 2.59 mas, the distance to this star is approximately 1,300 light-years.
HD 125351 or A Boötis is spectroscopic binary in the constellation Boötes. The system has an apparent magnitude of +4.97, with a spectrum matching a K-type giant star. It is approximately 233 light-years from Earth.
HR 2554, also known as V415 Carinae and A Carinae, is an eclipsing spectroscopic binary of the Algol type in the constellation of Carina whose apparent visual magnitude varies by 0.06 magnitude and is approximately 4.39 at maximum brightness. Its primary is a G-type bright giant star and its secondary is an A-type main-sequence star. It is approximately 553 light-years from Earth.
EO Aurigae is an eclipsing binary of Algol type in the northern constellation of Auriga. With a combined apparent magnitude of 7.71, it is too faint to be seen with the unaided eye.
LY Aurigae is a multiple star system in the constellation Auriga. It is an eclipsing binary variable star, dropping in brightness by 0.7 magnitudes every 4 days. The system is around a thousand light years away in the Auriga OB1 stellar association.
Tau Persei, also known as 18 Persei, is a binary star in the constellation of Perseus. The system is fairly close, and is located about 254 light-years away, based on its parallax.
36 Tauri is a binary star in the constellation of Taurus. Parallax measurements made by the Hipparcos spacecraft put it at a distance of over 1,000 light years from Earth. The combined apparent magnitude of the system is about 5.5, meaning it can barely be seen with the naked eye, according to the Bortle scale.