Astronomy:Lambda Pyxidis
  | |
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Pyxis |
| Right ascension | 09h 23m 12.25099s[1] |
| Declination | −28° 50′ 01.9420″[1] |
| Apparent magnitude (V) | 4.68[2] |
| Characteristics | |
| Spectral type | G8.5 IIIb Fe−1[3] |
| U−B color index | +0.63[2] |
| B−V color index | +0.91[2] |
| Astrometry | |
| Radial velocity (Rv) | +10.2[4] km/s |
| Proper motion (μ) | RA: −128.25[1] mas/yr Dec.: +20.70[1] mas/yr |
| Parallax (π) | 16.98 ± 0.24[1] mas |
| Distance | 192 ± 3 ly (58.9 ± 0.8 pc) |
| Absolute magnitude (MV) | +1.14[5] |
| Details | |
| Mass | 2.06[4] M☉ |
| Luminosity | 49[4] L☉ |
| Surface gravity (log g) | 3.04±0.06[6] cgs |
| Temperature | 5,126±22[6] K |
| Metallicity [Fe/H] | −0.05±0.02[6] dex |
| Rotational velocity (v sin i) | 4.4±0.2[5] km/s |
| Age | 1.3[4] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Lambda Pyxidis (λ Pyxidis) is a yellow-hued star in the southern constellation of Pyxis. It is visible to the naked eye, having an apparent visual magnitude of 4.68.[2] Based upon an annual parallax shift of 16.98 mas as seen from Earth,[1] it is located around 192 light years from the Sun.
Measurements of changes in the star's proper motion over time indicate this is an astrometric binary system. The visible component is an evolved G-type giant star with a stellar classification of G8.5 IIIb Fe−1[3] and a spectrum that displays an underabundance of iron with weak cyanogen lines.[8] It is a red clump star that is generating energy through the fusion of helium at its core.[9]
Lambda Pyxidis has double the mass of the Sun and is an estimated 1.3 billion years old.[4] It is radiating 49[4] times the Sun's luminosity from its photosphere at an effective temperature of 5,126 K.[6]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 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 Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series 71: 245, doi:10.1086/191373, Bibcode: 1989ApJS...71..245K.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal 150 (3): 88, doi:10.1088/0004-6256/150/3/88, Bibcode: 2015AJ....150...88L.
- ↑ 5.0 5.1 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.
- ↑ 6.0 6.1 6.2 6.3 Alves, S. et al. (April 2015), "Determination of the spectroscopic stellar parameters for 257 field giant stars", Monthly Notices of the Royal Astronomical Society 448 (3): 2749–2765, doi:10.1093/mnras/stv189, Bibcode: 2015MNRAS.448.2749A.
- ↑ "lam Pyx". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=lam+Pyx.
- ↑ Luck, R. Earle (February 1991), "Chemical abundances for cyanogen-weak giants", Astrophysical Journal Supplement Series 75: 579–610, doi:10.1086/191542, Bibcode: 1991ApJS...75..579L
- ↑ Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal 539 (2): 732–741, doi:10.1086/309278, Bibcode: 2000ApJ...539..732A.
 |  |
