Astronomy:Lambda Arae
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Ara |
| Right ascension | 17h 40m 23.826s[1] |
| Declination | −49° 24′ 56.10″[1] |
| Apparent magnitude (V) | 4.77[2] |
| Characteristics | |
| Spectral type | F4 V[3] |
| U−B color index | −0.04[2] |
| B−V color index | +0.40[2] |
| R−I color index | +0.22 |
| Variable type | 3.10[4] |
| Astrometry | |
| Radial velocity (Rv) | +3.3±0.3[5] km/s |
| Proper motion (μ) | RA: +104.233[1] mas/yr Dec.: −175.956[1] mas/yr |
| Parallax (π) | 47.7045 ± 0.1368[1] mas |
| Distance | 68.4 ± 0.2 ly (20.96 ± 0.06 pc) |
| Absolute magnitude (MV) | +3.06[6] |
| Details | |
| Mass | 1.37±0.04[1] M☉ |
| Radius | 1.711±0.035[1] R☉ |
| Luminosity | 4.69+0.03−0.05[1] L☉ |
| Surface gravity (log g) | 4.064+0.005−0.003[1] cgs |
| Temperature | 6,495+3−7[1] K |
| Metallicity [Fe/H] | −0.24[4] dex |
| Rotational velocity (v sin i) | 15.5[7] km/s |
| Age | 2.44±0.39[1] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Lambda Arae is a star in the southern constellation of Ara. Its name is a Bayer designation that is Latinized from λ Arae, and abbreviated Lambda Ara or λ Ara. The apparent visual magnitude of this star is 4.77,[2] making it bright enough to be seen with the naked eye. Based on parallax measurements, it is located at a distance of 68 light-years (21 parsecs) from Earth. This star is drifting further away from the Sun with a radial velocity of +3 km/s.[5]
The spectrum of this star matches a stellar classification of F4 V,[3] which places it among the category of F-type main sequence stars. It is an estimated 2.4 billion years old,[1] and is spinning with a projected rotational velocity of 15.5 km/s.[7] This star has 40% more mass than the Sun and a 70% greater radius. It shines with 4.7 times the luminosity of the Sun. The outer atmosphere is radiating this energy at an effective temperature of 6,495 K,[1] giving it the yellow-white hue of an F-type star. There is some evidence that this may be a binary star system consisting of two stars with identical masses.[7]
Examination of Lambda Arae with the Spitzer Space Telescope shows an excess of infrared emission at a wavelength of 70 μm. This suggests it may be orbited by a disk of dust at a radius of more than 15 astronomical units.[9]
References
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 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.
- ↑ 3.0 3.1 Gray, R. O. et al. (July 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): 161–170, doi:10.1086/504637, Bibcode: 2006AJ....132..161G.
- ↑ 4.0 4.1 Holmberg, J. et al. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics 501 (3): 941–947, doi:10.1051/0004-6361/200811191, Bibcode: 2009A&A...501..941H.
- ↑ 5.0 5.1 Gontcharov, G. A. (2006), "Pulkovo compilation of radial velocities for 35495 stars in a common system", Astronomy Letters 32 (11): 759–771, doi:10.1134/S1063773706110065, Bibcode: 2006AstL...32..759G.
- ↑ 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, doi:10.1051/0004-6361/201118724, Bibcode: 2012A&A...542A.116A.
- ↑ 7.0 7.1 7.2 Fuhrmann, K. et al. (August 2011), "Evidence for the nearby F4V star λ Ara as a binary system", Monthly Notices of the Royal Astronomical Society 415 (2): 1240–1243, doi:10.1111/j.1365-2966.2011.18764.x, Bibcode: 2011MNRAS.415.1240F.
- ↑ "lam Ara". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=lam+Ara.
- ↑ Lawler, S. M. et al. (November 2009), "Explorations Beyond the Snow Line: Spitzer/IRS Spectra of Debris Disks Around Solar-type Stars", The Astrophysical Journal 705 (1): 89–111, doi:10.1088/0004-637X/705/1/89, Bibcode: 2009ApJ...705...89L.
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