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Eta1 Pictoris 
Summary
η1 Pictoris, Latinised as Eta1 Pictoris, is a solitary[10] star in the southern constellation of Pictor. It is faintly visible to the naked eye with an apparent visual magnitude of +5.37.[2] Based upon an annual parallax shift of 38.35 mas as seen from the Earth,[1] the system is located 85 light years from the Sun. The star made its closest approach to the Sun about 1.1 million years ago with a perihelion passage of about 24 ly (7.5 pc).[11]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Pictor |
| Right ascension | 05h 02m 48.68641s[1] |
| Declination | −49° 09′ 05.0644″[1] |
| Apparent magnitude (V) | +5.37[2] |
| Characteristics | |
| Spectral type | F5 V[3] |
| U−B color index | −0.01[2] |
| B−V color index | +0.43[2] |
| Astrometry | |
| Radial velocity (Rv) | 21.4±2.8[4] km/s |
| Proper motion (μ) | RA: −43.67[1] mas/yr Dec.: +27.37[1] mas/yr |
| Parallax (π) | 38.35 ± 0.18 mas[1] |
| Distance | 85.0 ± 0.4 ly (26.1 ± 0.1 pc) |
| Absolute magnitude (MV) | 3.28[5] |
| Details | |
| Mass | 1.37[6] M☉ |
| Radius | 1.1[7] R☉ |
| Luminosity | 3.69[8] L☉ |
| Surface gravity (log g) | 4.17[6] cgs |
| Temperature | 6,631±225[6] K |
| Metallicity [Fe/H] | −0.05[3] dex |
| Rotational velocity (v sin i) | 22.7±1.1[5] km/s |
| Age | 2.15[6] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an F-type main sequence star with a stellar classification of F5 V[3] and it is chromospherically active.[3] It is an estimated 2.15[6] billion years old and is spinning with a projected rotational velocity of 22.7 km/s.[5] The star has 1.4[6] times the mass of the Sun and about 1.1[7] times the Sun's radius. It is radiating 3.7[8] times the Sun's luminosity from its photosphere at an effective temperature of roughly 6,631 K.[6]
References edit
- ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
- ^ a b c d Cousins, A. W. J. (1973), "UBV photometry of some southern stars", Monthly Notes of the Astronomical Society of Southern Africa, 32: 11, Bibcode:1973MNSSA..32...11C.
- ^ a b c d Gray, R. O.; et al. (2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal, 132 (1): 161–70, arXiv:astro-ph/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637, S2CID 119476992.
- ^ De Bruijne, J. H. J.; Eilers, A.-C. (2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: A61, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347.
- ^ a b c Ammler-von Eiff, Matthias; Reiners, Ansgar (June 2012), "New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?", Astronomy & Astrophysics, 542: A116, arXiv:1204.2459, Bibcode:2012A&A...542A.116A, doi:10.1051/0004-6361/201118724, S2CID 53666672.
- ^ a b c d e f g David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID 33401607.
- ^ a b Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics, 367 (Third ed.): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
- ^ a b McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
- ^ "eta01 Pic -- Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2017-06-22.
- ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
- ^ Bailer-Jones, C. A. L. (March 2015), "Close encounters of the stellar kind", Astronomy & Astrophysics, 575: 13, arXiv:1412.3648, Bibcode:2015A&A...575A..35B, doi:10.1051/0004-6361/201425221, S2CID 59039482, A35.