| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Pisces |
| Right ascension | 00h 48m 58.70805s[1] |
| Declination | +16° 56′ 26.3132″[1] |
| Apparent magnitude (V) | 5.07[2] |
| Characteristics | |
| Spectral type | F8 V + F8 V[3] |
| B−Vcolor index | 0.502[2] |
| Astrometry | |
| Radial velocity (Rv) | +3.76±0.08[4] km/s |
| Proper motion (μ) | RA: −2.87[1]mas/yr Dec.: −202.05[1]mas/yr |
| Parallax (π) | 42.64±0.27 mas[1] |
| Distance | 76.5 ± 0.5 ly (23.5 ± 0.1 pc) |
| Absolute magnitude (MV) | 3.22[5] |
| Orbit[6] | |
| Period (P) | 13.8244906±0.000043 d |
| Semi-major axis (a) | 6.545±0.0133 mas (0.073953±0.000048 AU) |
| Eccentricity (e) | 0.23657±0.00063 |
| Inclination (i) | 73.92±0.80° |
| Longitude of the node (Ω) | 207.41±0.65° |
| Periastronepoch (T) | 50905.984 ± 0.015 MJD |
| Argument of periastron (ω) (secondary) | 203.057±0.073° |
| Semi-amplitude (K1) (primary) | 57.552±0.037 km/s |
| Semi-amplitude (K2) (secondary) | 59.557±0.038 km/s |
| Details[3] | |
| 64 Psc Aa | |
| Mass | 1.223±0.021 M☉ |
| Radius | 1.25±0.08 R☉ |
| Luminosity | 2.12 L☉ |
| Temperature | 6,250±150 K |
| Metallicity[Fe/H] | 0.00[7] dex |
| Age | 6.81[8] Gyr |
| 64 Psc Ab | |
| Mass | 1.170±0.018 M☉ |
| Radius | 1.18±0.10 R☉ |
| Luminosity | 1.85 L☉ |
| Temperature | 6,200±200 K |
| Other designations | |
| 64 Psc,BD+16° 76,FK5 1020,GJ 9031,HD 4676,HIP 3810,HR 225,SAO 92099,WDS J00490+1656A[9] | |
| Database references | |
| SIMBAD | data |
64 Piscium is theFlamsteed designation for a closebinary star system in thezodiacconstellation ofPisces. It can be viewed with the naked eye, with the components having a combinedapparent visual magnitude of 5.07.[2] An annualparallax shift of 42.64 mas provides a distance estimate of 46.5 light years. The system is moving further from the Sun with aradial velocity of +3.76 km/s.[4]
This is a double-linedspectroscopic binary system consisting of two similar components[3] designated Aa and Ab.[10] The initial orbital elements were determined by Abt and Levy (1976), giving anorbital period of 13.8 days. In Boden et al. (1999), the full set oforbital elements were derived using measurements with thePalomar Testbed Interferometer.[11] Nadal et al. (1979) suggested that some variation in the measurements may be caused by a third component in the system,[12] but this was not supported by the results from Boden et al. (1999).[11] In 2005, Maciej Konacki pioneered a new technique for accurately determining theradial velocity of a double-lined binary system, which allowed the elements to be further refined. This yielded anorbital period of 13.82449 days, aneccentricity of 0.2366, and an angularsemimajor axis of 6.55 mas.[6]
Both stars in this system have aspectrum matching astellar classification of F8 V,[3] indicating they are ordinaryF-type main-sequence stars that are generating energy viahydrogen fusion at theircores. The orbital measurements of this system allows the masses of the two stars to be determined accurately: the primary component has 1.22 times themass of the Sun while the secondary has 1.17 times the Sun's mass.[3] Both stars are larger and brighter than the Sun, with higher temperaturephotospheres − havingeffective temperatures of around 6,200 K compared to 5,772 K for the Sun.[13] The age of the system is estimated as 6.8[8] billion years and they have a similarelement abundance as the Sun.[7]
In 2010, the system was identified as adebris disk candidate based upon the detection of aninfrared excess at awavelength of 24 μm.[14] This dust has a mean temperature of 300 K and is orbiting at a radius of 1.7 AU,[15] compared to a projected linear separation of 0.23 AU for the components.[10]
TheWashington Double Star Catalog lists two additional visual components. Component B is a magnitude 12.6 star at anangular separation of 77 arcseconds from the primary system. Component C is magnitude 13.0 and is located 71 arcseconds away. It is unknown if either is gravitationally bound to 64 Piscium Aab, but if they are then theprojected separations are about 1,800 AU with an orbital period of around 50,000 years.[11]
