Lambda Pyxidis

Lambda Pyxidis
	Location of λ Pyxidis (circled)
Observation data; Epoch J2000.0 Equinox J2000.0 (ICRS)
Constellation	Pyxis
Right ascension	09h 23m 12.25099s
Declination	−28° 50′ 01.9420″
Apparent magnitude (V)	4.68
Characteristics
Evolutionary stage	red clump
Spectral type	G8.5 IIIb Fe−1
U−B color index	+0.63
B−V color index	+0.91
Astrometry
Radial velocity (Rv)	+10.2 km/s
Proper motion (μ)	RA: −128.25 mas/yr ; Dec.: +20.70 mas/yr
Parallax (π)	16.98±0.24 mas
Distance	192 ± 3 ly ; (58.9 ± 0.8 pc)
Absolute magnitude (MV)	+0.93±0.02
Details
Mass	2.47±0.06 M☉
Radius	8.03±0.14 R☉
Luminosity	41±1 L☉
Surface gravity (log g)	3.030±0.059 cgs
Temperature	5,152±28 K
Metallicity [Fe/H]	+0.004±0.025 dex
Rotational velocity (v sin i)	4.4±0.2 km/s
Other designations
	λ Pyx, CPD−28°3717, FK5 2747, HD 81169, HIP 46026, HR 3733, SAO 177374
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^[4] and a spectrum that displays an underabundance of iron with weak cyanogen lines.^[9] It is a red clump star that is generating energy through the fusion of helium at its core.^[3]

Lambda Pyxidis has 2.47 times the mass of the Sun and 8.0 times the radius of the Sun. It is radiating 41 times the Sun's luminosity from its photosphere at an effective temperature of 5,152 K.^[6]

References

^ ^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 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 Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal, 539 (2): 732–741, arXiv:astro-ph/0003329, Bibcode:2000ApJ...539..732A, doi:10.1086/309278, S2CID 16673121.
^ ^a ^b Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373.
^ Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal, 150 (3): 88, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88, S2CID 118505114.
^ ^a ^b ^c Ottoni, G.; Udry, S.; Ségransan, D.; Buldgen, G.; Lovis, C.; Eggenberger, P.; Pezzotti, C.; Adibekyan, V.; Marmier, M.; Mayor, M.; Santos, N. C.; Sousa, S. G.; Lagarde, N.; Charbonnel, C. (2022-01-01), "CORALIE radial-velocity search for companions around evolved stars (CASCADES). I. Sample definition and first results: Three new planets orbiting giant stars", Astronomy and Astrophysics, 657: A87, arXiv:2201.01528, Bibcode:2022A&A...657A..87O, doi:10.1051/0004-6361/202040078, ISSN 0004-6361. Lambda Pyx's database entry at VizieR.
^ 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.
^ "lam Pyx". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-07-16.{{cite web}}: CS1 maint: postscript (link)
^ Luck, R. Earle (February 1991), "Chemical abundances for cyanogen-weak giants", Astrophysical Journal Supplement Series, 75: 579–610, Bibcode:1991ApJS...75..579L, doi:10.1086/191542

[vanLeeuwen2007-1] ^ ^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.

[Johnson1966-2] 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.

[Alves2000-3] Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal, 539 (2): 732–741, arXiv:astro-ph/0003329, Bibcode:2000ApJ...539..732A, doi:10.1086/309278, S2CID 16673121.

[perkins1989-4] Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373.

[luck2015-5] Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal, 150 (3): 88, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88, S2CID 118505114.

[ottoni-6] Ottoni, G.; Udry, S.; Ségransan, D.; Buldgen, G.; Lovis, C.; Eggenberger, P.; Pezzotti, C.; Adibekyan, V.; Marmier, M.; Mayor, M.; Santos, N. C.; Sousa, S. G.; Lagarde, N.; Charbonnel, C. (2022-01-01), "CORALIE radial-velocity search for companions around evolved stars (CASCADES). I. Sample definition and first results: Three new planets orbiting giant stars", Astronomy and Astrophysics, 657: A87, arXiv:2201.01528, Bibcode:2022A&A...657A..87O, doi:10.1051/0004-6361/202040078, ISSN 0004-6361. Lambda Pyx's database entry at VizieR.

[vonEiff2012-7] 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.

[SIMBAD-8] "lam Pyx". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-07-16.{{cite web}}: CS1 maint: postscript (link)

[Luck1991-9] Luck, R. Earle (February 1991), "Chemical abundances for cyanogen-weak giants", Astrophysical Journal Supplement Series, 75: 579–610, Bibcode:1991ApJS...75..579L, doi:10.1086/191542

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Lambda Pyxidis

References

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