Lambda Arietis
  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aries[1] |
| Right ascension | 01h 57m 55.717s[2] |
| Declination | +23° 35′ 45.83″[2] |
| Apparent magnitude (V) | 4.79[3] (4.95/7.75)[4] |
| Characteristics | |
| Spectral type | F0 V + G1 V[4] |
| U−B color index | +0.09[3] |
| B−V color index | +0.290[1] |
| R−I color index | +0.16[5] |
| Astrometry | |
| λ Ari A | |
| Radial velocity (Rv) | −1.4[6] km/s |
| Proper motion (μ) | RA: −92.295 mas/yr[2] Dec.: −13.207 mas/yr[2] |
| Parallax (π) | 24.7748±0.2189 mas[2] |
| Distance | 132 ± 1 ly (40.4 ± 0.4 pc) |
| Absolute magnitude (MV) | 1.81[1] |
| λ Ari B | |
| Radial velocity (Rv) | −8[6] km/s |
| Proper motion (μ) | RA: −91.839 mas/yr[7] Dec.: −19.370 mas/yr[7] |
| Parallax (π) | 24.8689±0.0446 mas[7] |
| Distance | 131.2 ± 0.2 ly (40.21 ± 0.07 pc) |
| Details | |
| λ Ari A | |
| Mass | 1.65±0.27[7] M☉ |
| Radius | 2.45±0.09[7] R☉ |
| Luminosity | 15.43±0.66[7] L☉ |
| Surface gravity (log g) | 3.88±0.08[7] cgs |
| Temperature | 7,311±125[7] K |
| Metallicity [Fe/H] | +0.01[8] dex |
| Rotational velocity (v sin i) | 107[9] km/s |
| Age | 618[10] Myr |
| λ Ari B | |
| Mass | 1.13±0.15[7] M☉ |
| Radius | 1.14±0.06[7] R☉ |
| Luminosity | 1.60±0.05[7] L☉ |
| Surface gravity (log g) | 4.37±0.08[7] cgs |
| Temperature | 6,072±130[7] K |
| Metallicity [Fe/H] | −0.03[8] dex |
| Other designations | |
| 9 Arietis, HD 11973, HIP 9153, HR 569, SAO 75051, ADS 1563, CCDM 01580+2336, WDS J01579+2336 | |
| λ Ari A: BD+22 288, GC 2366, TIC 60986648[11] | |
| λ Ari B: BD+22 289, GC 2367, PPM 91238, TIC 60986644[12] | |
| Database references | |
| SIMBAD | data |
Lambda Arietis is a double star in the northern constellation of Aries. Its name is a Bayer designation that is Latinized from λ Arietis, and abbreviated Lambda Ari or λ Ari. Based upon an annual parallax shift of 25.32 arcseconds, this system is approximately 129 light-years (40 parsecs) distant from Earth. The pair have a combined apparent visual magnitude of 4.79,[3] which is bright enough to be viewed with the naked eye. Because the yellow secondary is nearly three magnitudes fainter than the white primary, they are a challenge to split with quality 7× binoculars but are readily resolvable at 10×.[13]
The brighter component is an F-type main sequence star with a visual magnitude of 4.95 and a stellar classification of F0 V.[4] It is an estimated 618[10] million years old with a high rate of rotation, showing a projected rotational velocity of 107 km/s.[9] This star has 1.7 times the mass of the Sun and 2.5 times the Sun's radius. It is radiating 15 times the luminosity of the Sun from its photosphere at an effective temperature of 7,311 K.[7]
At an angular separation of 37.4 arcseconds is fainter, magnitude 7.75 companion. This is a G-type main sequence star with a classification of G1 V.[4] The star is at a similar distance as the brighter component, and has a comparable proper motion.[7] In 1988, Helmut Abt listed this as a physical pair, showing a common proper motion with a projected separation of 1,600 au.[14]
References
[edit]- ^ a b c Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015. XHIP record for this object at VizieR.
- ^ a b c d Vallenari, A.; et al. (Gaia collaboration) (2023), "Gaia Data Release 3. Summary of the content and survey properties", Astronomy and Astrophysics, 674: A1, arXiv:2208.00211, Bibcode:2023A&A...674A...1G, doi:10.1051/0004-6361/202243940, S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
- ^ a b c d 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.
- ^ Mallama, A. (2014), "Sloan Magnitudes for the Brightest Stars", Journal of the American Association of Variable Star Observers (Jaavso), 42 (2): 443, Bibcode:2014JAVSO..42..443M.
- ^ a b Wilson, Ralph Elmer (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication, Washington: Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W.
- ^ a b c d e f g h i j k l m n Stassun, Keivan G.; et al. (October 2019), "The Revised TESS Input Catalog and Candidate Target List", The Astronomical Journal, 158 (4): 138, arXiv:1905.10694, Bibcode:2019AJ....158..138S, doi:10.3847/1538-3881/ab3467, hdl:1721.1/124721, ISSN 0004-6256, S2CID 166227927.
- ^ a b Soubiran, C.; et al. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics, 515: A111, arXiv:1004.1069, Bibcode:2010A&A...515A.111S, doi:10.1051/0004-6361/201014247, S2CID 118362423.
- ^ a b Royer, F.; et al. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224, S2CID 18475298.
- ^ a b 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.
- ^ "lam Ari", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2012-08-07.
- ^ "lam Ari B", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2025-05-06.
- ^ Harrington, Philip S. (2010), Cosmic Challenge: The Ultimate Observing List for Amateurs, Cambridge University Press, p. 113, ISBN 978-0521899369
- ^ Abt, Helmut A. (August 1988), "Maximum Separations among Cataloged Binaries", Astrophysical Journal, 331: 922, Bibcode:1988ApJ...331..922A, doi:10.1086/166609.
