UZ Pyxidis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Pyxis |
| Right ascension | 08h 46m 36.3323s[2] |
| Declination | −29° 43′ 41.203″[2] |
| Apparent magnitude (V) | 6.99 - 7.63[3] |
| Characteristics | |
| Spectral type | C55J (R8)[3] |
| U−B color index | +2.99[4] |
| B−V color index | +2.01[4] |
| Variable type | SRb[5] |
| Astrometry | |
| Radial velocity (Rv) | 13.00[6] km/s |
| Proper motion (μ) | RA: −5.767[2] mas/yr Dec.: 1.674[2] mas/yr |
| Parallax (π) | 0.8949 ± 0.0183 mas[2] |
| Distance | 3,640 ± 70 ly (1,120 ± 20 pc) |
| Absolute magnitude (MV) | −1.2[7] |
| Details | |
| Mass | 2.1[8] M☉ |
| Radius | 221[9] R☉ |
| Luminosity | 5,649[10] L☉ |
| Surface gravity (log g) | −0.236[8] cgs |
| Temperature | 3,325[10] K |
| Metallicity [Fe/H] | −0.32[8] dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
UZ Pyxidis (HD 75021) is a semiregular variable star in the constellation Pyxis. It is located about 3,600 light-years (1,100 parsecs) away from the Earth.
UZ Pyxidis lies directly between α and γ Pyxidis. It has a common proper motion companion, HD 75022,[11] less than 2' away but the two are not listed in double star catalogues.
UZ Pyxidis is a carbon star. These types of stars are known for having large amounts of carbon in their atmospheres, forming carbon compounds that make the star appear strikingly red. It was first recognised as having an unusual spectrum in 1893.[12] Under the Morgan–Keenan classification of carbon stars, UZ Pyxidis' spectral type is C55; if it were a normal giant star, this would correspond to a spectral type of about K5.[13] It is also unusual in that it has very strong isotopic bands of C2 and CN.[14]
There were hints that the star is variable as early as the late 19th century,[15] and its variability was firmly estabilished by Olin J. Eggen in 1972.[16][11] The variable star designation UZ Pyxidis was assigned in 1978.[17] UZ Pyxidis is classified as a semiregular variable with a dominant period of 159.6 days. It varies in brightness between magnitude 6.99 and 7.63.[3]
References
[edit]- ^ "ASAS All Star Catalogue". The All Sky Automated Survey. Retrieved 8 December 2021.
- ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
- ^ a b c Otero, Sebastian Alberto (15 April 2012). "VSX: Detail for UZ Pyx". The International Variable Star Index. American Association of Variable Star Observers. Retrieved 18 January 2017.
- ^ a b Platais, I.; Pourbaix, D.; Jorissen, A.; Makarov, V. V.; Berdnikov, L. N.; Samus, N. N.; Lloyd Evans, T.; Lebzelter, T.; Sperauskas, J. (2003). "Hipparcos red stars in the HpVT2 and VIC systems". Astronomy and Astrophysics. 397 (3): 997–1010. arXiv:astro-ph/0211048. Bibcode:2003A&A...397..997P. doi:10.1051/0004-6361:20021589. S2CID 17382277.
- ^ Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
- ^ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
- ^ Gontcharov, G. A. (2011). "The red giant branch in the Tycho-2 catalogue". Astronomy Letters. 37 (10): 707–717. arXiv:1607.00557. Bibcode:2011AstL...37..707G. doi:10.1134/S1063773711090040. S2CID 119272127.
- ^ a b c Anders, F.; Khalatyan, A.; Queiroz, A. B. A.; Chiappini, C.; Ardevol, J.; Casamiquela, L.; Figueras, F.; Jimenez-Arranz, O.; Jordi, C.; Monguio, M.; Romero-Gomez, M.; Altamirano, D.; Antoja, T.; Assaad, R.; Cantat-Gaudin, T.; Castro-Ginard, A.; Enke, H.; Girardi, L.; Guiglion, G.; Khan, S.; Luri, X.; Miglio, A.; Minchev, I.; Ramos, P.; Santiago, B. X.; Steinmetz, M. (2022). "VizieR Online Data Catalog: StarHorse2, Gaia EDR3 photo-astrometric distances (Anders+, 2022)". Vizier Online Data Catalog. Bibcode:2022yCat.1354....0A.
- ^ Stassun, Keivan G.; et al. (2019-10-01). "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 Bergeat, J.; Chevallier, L. (2005). "The mass loss of C-rich giants". Astronomy and Astrophysics. 429: 235–246. arXiv:astro-ph/0601366. Bibcode:2005A&A...429..235B. doi:10.1051/0004-6361:20041280. S2CID 56424665.
- ^ a b Eggen, O. J. (1972). "The classification of intrinsic variable stars. I. The red variables of type N". Astrophysical Journal. 174: 45. Bibcode:1972ApJ...174...45E. doi:10.1086/151467.
- ^ Fleming, W. P. (1893). "Stars having peculiar spectra". Astronomy and Astro-Physics. 12: 546. Bibcode:1893AstAp..12..546F.
- ^ Keenan, P. C.; Morgan, W. W. (1941). "The Classification of the Red Carbon Stars". The Astrophysical Journal. 94: 501. Bibcode:1941ApJ....94..501K. doi:10.1086/144356.
- ^ Keenan, P. C. (1993). "Revised MK Spectral Classification of the Red Carbon Stars". Publications of the Astronomical Society of the Pacific. 105: 905. Bibcode:1993PASP..105..905K. doi:10.1086/133252.
- ^ Fleming, W. P. (1893). "Stars having peculiar spectra". Astronomy and Astro-Physics (formerly The Sidereal Messenger). 12: 546–547. Bibcode:1893AstAp..12..546F. Retrieved 21 December 2024.
- ^ Eggen, O. J. (1972). "The classification of intrinsic variable stars. II. The red variables of S and related types". Astrophysical Journal. 177: 489. Bibcode:1972ApJ...177..489E. doi:10.1086/151725.
- ^ Kholopov, P. N.; Kukarkina, N. P.; Perova, N. B. (1978). "63rd Name-List of Variable Stars". Information Bulletin on Variable Stars. 1414: 1. Bibcode:1978IBVS.1414....1K.
