72 Ophiuchi
Template:Location mark Location of 72 Ophiuchi (circled) | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ophiuchus |
| Right ascension | Template:RA[1] |
| Declination | Template:DEC[1] |
| Apparent magnitude (V) | 3.73[2] + 14.0[3] |
| Characteristics | |
| Spectral type | A5 V[4] |
| U−B Template:Engvar | +0.10[2] |
| B−V Template:Engvar | +0.12[2] |
| Astrometry | |
| Radial velocity (Rv) | −23.90[5] km/s |
| Proper motion (μ) | RA: −62.17[1] mas/yr Dec.: +79.66[1] mas/yr |
| Parallax (π) | 37.55±0.21 mas[1] |
| Distance | Template:Rnd ± Template:Rnd ly (Template:Rnd ± Template:Rnd pc) |
| Absolute magnitude (MV) | 1.58[6] |
| Details | |
| Mass | 1.99[7] Template:Solar mass |
| Radius | 1.9[8] Template:Solar radius |
| Luminosity | 20[7] Template:Solar luminosity |
| Surface gravity (log g) | 4.04[9] cgs |
| Temperature | 8,718[9] K |
| Metallicity [Fe/H] | +0.09[6] dex |
| Rotational velocity (v sin i) | 65[7] km/s |
| Age | 250[9] Myr |
| Metallicity [Fe/H] | {{{metal_fe2}}} dex |
| Other designations | |
| Template:Odlist[10] | |
| Database references | |
| SIMBAD | data |
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72 Ophiuchi is a binary star[3] system in the equatorial constellation of Ophiuchus. It is visible to the naked eye as a faint, white-hued point of light with a combined apparent visual magnitude of 3.73.[2] It is located approximately 86.9 light years away from the Sun based on parallax,[1] but is moving closer with a heliocentric radial velocity of -23.9 km/s.[5]
As of 2008, the pair had an angular separation of Script error: No such module "val"..[3] According to Gray et al. (2003), the primary component has a stellar classification of A5 V,[4] matching an A-type main-sequence star. Cowley et al. (1969) had assigned it to a class of A4 IVs,[11] suggesting it is a sharp-lined (s) subgiant star. The latter class is still in use by some sources.[7][3][12]
The primary is 250[9] million years old with double[7] the mass of the Sun and is spinning with a moderate projected rotational velocity of 65 km/s.[7] It is radiating 20[7] times the luminosity of the Sun from its photosphere at an effective temperature of 8,718 K.[9] It displays an infrared excess, suggesting a debris disk is orbiting the star with a mean separation of Script error: No such module "val". and temperature of 60 K.[13] The system is a source of X-ray emission,[12] which is most likely coming from the 14th[3] magnitude companion.[12]
There are additional visual companions: component C with magnitude 11.5 lies at an angular separation of Script error: No such module "val". from the primary,[14] while component D, has magnitude 14.8 and separation 24".[15]
This star was once considered part of the obsolete constellation Taurus Poniatovii, the brightest star in it. After the International Astronomical Union officially recognised constellations, it was placed in Ophiuchus.[16]
References
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- ↑ a b c d e f Script error: No such module "Citation/CS1". Vizier catalog entry
- ↑ a b c d Script error: No such module "Citation/CS1".
- ↑ a b c d e Script error: No such module "Citation/CS1".
- ↑ a b Script error: No such module "Citation/CS1".
- ↑ a b Script error: No such module "Citation/CS1".
- ↑ a b Script error: No such module "Citation/CS1". Vizier catalog entry
- ↑ a b c d e f g Script error: No such module "Citation/CS1". Vizier catalog entry
- ↑ Script error: No such module "Citation/CS1". Vizier catalog entry
- ↑ a b c d e Script error: No such module "Citation/CS1". Vizier catalog entry
- ↑ Template:Cite simbad
- ↑ Script error: No such module "Citation/CS1".
- ↑ a b c Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "Citation/CS1". Vizier catalog entry
- ↑ Script error: No such module "citation/CS1".
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