Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Centaurus |
Right ascension | 13h 51m 49.60s [1] |
Declination | −32° 59′ 38.7″ [1] |
Apparent magnitude (V) | 4.32 [2] (4.52 + 5.97) [3] |
Characteristics | |
Spectral type | B5 III-IVp [4] + B8 V [5] |
B−V color index | −0.146±0.003 [2] |
Variable type | Eclipsing? [6] |
Astrometry | |
Radial velocity (Rv) | +7.5±1.6 [7] km/s |
Absolute magnitude (MV) | −0.46 [2] |
A | |
Proper motion (μ) | RA: −34.698±0.864 [8] mas/yr Dec.: −27.909±0.792 [8] mas/yr |
Parallax (π) | 11.0982 ± 0.4267 mas |
Distance | 290 ± 10 ly (90 ± 3 pc) |
B | |
Proper motion (μ) | RA: −36.737±0.266 [9] mas/yr Dec.: −23.774±0.189 [9] mas/yr |
Parallax (π) | 10.2659 ± 0.1380 mas [9] |
Distance | 318 ± 4 ly (97 ± 1 pc) |
Orbit [10] | |
Primary | Ba |
Companion | Bb |
Period (P) | 17.428 d |
Eccentricity (e) | 0.21 |
Periastron epoch (T) | 2443296.44 JD |
Argument of periastron (ω) (secondary) | 15° |
Semi-amplitude (K1) (primary) | 17 km/s |
Details | |
3 Cen A | |
Mass | 5.0±0.1 [11] M☉ |
Surface gravity (log g) | 3.80 [12] cgs |
Temperature | 17,500 [12] K |
Age | 47.4±7.3 [11] Myr |
3 Cen B | |
Mass | 2.47±0.10 [5] M☉ |
Radius | 2.8 [13] R☉ |
Luminosity | 50.2+11.7 −9.5 [5] L☉ |
Temperature | 9,638+67 −66 [5] K |
Rotational velocity (v sin i) | 135 [5] km/s |
Other designations | |
3 Cen A: GC 18724, HD 120709, HR 5210, SAO 204916 | |
3 Cen B: GC 18725, HD 120710, HR 5211, SAO 204917 | |
Database references | |
SIMBAD | data |
A | |
B |
3 Centauri is a triple star [3] system in the southern constellation of Centaurus, [14] located approximately 300 light years from the Sun. [8] [9] It is visible to the naked eye as a faint, blue-white hued star with a combined apparent visual magnitude of 4.32. [2] As of 2017, the two visible components had an angular separation of 7.851″ along a position angle of 106°. [3] The system has the Bayer designation k Centauri; 3 Centauri is the Flamsteed designation. It is a suspected eclipsing binary with a variable star designation V983 Centauri. [6]
The brighter member, designated component A, is a magnitude 4.52 [3] chemically peculiar star of the helium-weak (CP4) variety, and has a stellar classification of B5 III-IVp. [4] The spectrum of the star displays overabundances of elements such as nitrogen, phosphorus, manganese, iron, and nickel, while carbon, oxygen, magnesium, aluminium, sulfur, and chlorine appear underabundant relative to the Sun. [12] Weak emission line features are also visible. [15]
The magnitude 5.97 [3] secondary, component B, is a single-lined spectroscopic binary star system with an orbital period of 17.4 days and an eccentricity of 0.21. [10] The pair have an angular separation of 2.485 mas . The visible component is a B-type main-sequence star with a class of B8 V. [5]
ο Tauri, Latinized as Omicron Tauri, is a binary star system in the constellation Taurus, near the constellation border with Cetus. It has a yellow hue and is visible to the naked eye with an apparent visual magnitude of 3.61. It is approximately 191 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −20 km/s. As the westernmost bright point of light in Taurus, this system has the Flamsteed designation 1 Tauri; Omicron Tauri is the Bayer designation.
Kappa Cancri, Latinized from κ Cancri, is a blue-white hued binary star system in the zodiac constellation of Cancer. It is faintly visible to the naked eye with an apparent visual magnitude of +5.23. The magnitude difference between the two stars is about 2.6. Based upon an annual parallax shift of 5.3209 mas as seen from the Earth, the system is located roughly 610 light-years from the Sun.
Nu Cancri, Latinised from ν Cancri, is a binary star in the zodiac constellation of Cancer. It is faintly visible to the naked eye with an apparent visual magnitude of +5.46. Based upon an annual parallax shift of 8.31 mas as seen from the Earth, the star is located roughly 390 light-years from the Sun.
4 Cassiopeiae is a red giant in the northern constellation of Cassiopeia, located approximately 790 light-years away from the Sun. It is visible to the naked eye as a faint, red-hued star with a baseline apparent visual magnitude of 4.96. At the distance of this system, its visual magnitude is diminished by an extinction of 0.56 due to interstellar dust. This system is moving closer to the Earth with a heliocentric radial velocity of −39 km/s.
Omega Cassiopeiae is a binary star system in the northern constellation of Cassiopeia. It has a combined apparent visual magnitude of +4.99, which means it is a faint star but visible to the naked eye. Based upon an annual parallax shift of 4.65 mas as seen from Earth, this system is located roughly 730 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction of 0.16 due to interstellar dust.
Lambda Centauri, Latinized from λ Centauri, is a star in the southern circumpolar constellation of Centaurus. It has an apparent visual magnitude of +3.13, which is bright enough to be seen with the naked eye from the Southern Hemisphere and places it among the brighter members of this constellation. The star is close enough that its distance can be determined directly using the parallax technique, which gives a value of approximately 470 light-years from the Sun. Although a putative solitary star, it has a candidate proper motion companion at an angular separation of 0.73 arcseconds along a position angle of 135°. The nebula IC 2944 lies nearby.
Upsilon2 Centauri is a binary star system in the southern constellation Centaurus. It is visible to the naked eye with an apparent visual magnitude of +4.33. Based upon an annual parallax shift of just 2.57 mas as seen from Earth, this star is located roughly 1,300 light years from the Sun. Relative to its neighbors, the system has a peculiar velocity of 39.2+8.8
−15.2 km/s and it may form a runaway star system.
D Centauri is a double star in the southern constellation of Centaurus. The system is faintly visible to the naked eye as a point of light with a combined apparent magnitude of +5.31; the two components are of magnitude 5.78 and 6.98, respectively. It is located at a distance of approximately 610 light years from the Sun based on parallax, and is drifting further away with a radial velocity of ~10 km/s.
Rho Centauri, Latinized from ρ Centauri, is a binary star system in the southern constellation of Centaurus. It is visible to the naked eye as a blue-white hued point of light with a combined apparent visual magnitude of +3.97. The system is located approximately 276 light years from the Sun based on parallax, and is drifting further away with a radial velocity of around +15 km/s. It is a proper motion member of the Lower Centaurus–Crux sub-group in the Scorpius–Centaurus OB association, the nearest such association of co-moving massive stars to the Sun.
Psi Centauri, which is Latinized from ψ Centauri, is a binary star system in the southern constellation of Centaurus. It is visible to the naked eye with a baseline apparent visual magnitude of +4.05. The distance to this system is approximately 259 light years based on parallax. The radial velocity is poorly constrained, but it appears to be slowly drifting away from the Sun at the rate of +2 km/s.
1 Centauri, or i Centauri, is a yellow-white-hued binary star system in the southern constellation Centaurus. It can be seen with the naked eye, having an apparent visual magnitude of +4.23. Based upon an annual parallax shift of 51.54 mas as seen from Earth's orbit, it is located 51.5 light-years from the Sun. The system is moving closer to the Sun with a radial velocity of −21.5 km/s.
Xi2 Centauri, Latinized from ξ2 Centauri, is a triple star system in the southern constellation of Centaurus. It is visible to the naked eye with an apparent visual magnitude of 4.30, and forms a wide optical double with the slightly dimmer ξ1 Centauri. Based upon an annual parallax shift of 6.98 mas, Xi2 Centauri lies roughly 470 light years from the Sun. At that distance, the visual magnitude is diminished by an interstellar extinction factor of 0.32 due to intervening dust.
HD 125823, also known as V761 Centauri or a Centauri, is a variable star in the constellation Centaurus. It is a blue-white star that is visible to the naked eye with a mean apparent visual magnitude of +4.41. The distance to this star is approximately 460 light years based on parallax measurements. It is a member of the Upper Centaurus–Lupus subgroup of the Scorpius–Centaurus association.
HD 113703, also known by the Bayer designation f Centauri, is a multiple star system in the southern constellation of Centaurus. The combined apparent visual magnitude of this system is +4.71, which is sufficient to make it faintly visible to the naked eye. The distance to this system is approximately 400 light years based on parallax measurements. It is a member of the Lower Centaurus Crux subgroup of the Scorpius–Centaurus association.
K Centauri is a possible binary star in the southern constellation of Centaurus. It has a white hue and is bright enough to be visible to the naked eye, having an apparent visual magnitude of +5.04.
13 Vulpeculae is a blue giant with a stellar classification of class B9.5III in the northern constellation Vulpecula. It is visible to the naked eye as a faint, blue-white hued star with an apparent visual magnitude of 4.57 and it is approximately 339 light years away from the Sun based on parallax. The star is radiating 180 times the luminosity of the Sun from its photosphere at an effective temperature of 8,801 K.
26 Vulpeculae is a close binary star system in the northern constellation of Vulpecula, around 644 light years away from the Sun. It is a challenge to view with the naked eye, having an apparent visual magnitude of 6.40. The star is moving closer to the Earth with a heliocentric radial velocity of −63 km/s, and is expected to come within 225 light-years in around 2.6 million years.
Iota Coronae Borealis, Latinized from ι Coronae Borealis, is a binary star system in the constellation Corona Borealis. It is visible to the naked eye with a combined apparent visual magnitude of is 4.96. Based upon an annual parallax shift of 10.46 mas as seen from the Earth, it is located about 312 light years from the Sun.
HD 137058 is a star in the southern constellation of Lupus. Eggleton and Tokovinin (2008) list it as a single star, although Nitschelm and David (2011) noted it may be a double-lined spectroscopic binary. Its apparent visual magnitude is 4.60, which is bright enough to be visible to the naked eye. Based upon an annual parallax shift of 13.6 mas, it is located 240 light years away.
Y Centauri or Y Cen is a semiregular variable star in the constellation of Centaurus.