T Chamaeleontis (T Cha), also known as HIP 58285, is a T Tauri star located in the southern circumpolar constellation Chamaeleon. It has an apparent magnitude that ranges from 10.05 to 14.50,[3] which is below the limit for naked eye visibility. Gaia DR3 parallax measurements place the object 335 light years away[2] and it is currently receding with a heliocentric radial velocity of 13.8 km/s.[9] At its current distance, T Cha's average brightness is diminished by 0.31 magnitudes due to extinction from interstellar dust. It has an average absolute magnitude of +6.55.[10]

T Chamaeleontis

A visual band light curve for T Chamaeleontis, plotted from AAVSO data[1]
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Chamaeleon
Right ascension 11h 57m 13.52451s[2]
Declination −79° 21′ 31.5305″[2]
Apparent magnitude (V) 10.05 - 14.50[3]
Characteristics
Evolutionary stage T Tauri star[4]
Spectral type K0e[5]
U−B color index +0.63[6]
B−V color index +1.14[6]
J−K color index +1.67[7]
Variable type Orion variable[8]
Astrometry
Radial velocity (Rv)13.8±0.1[9] km/s
Proper motion (μ) RA: −41.586 mas/yr[2]
Dec.: −8.655 mas/yr[2]
Parallax (π)9.7356 ± 0.0332 mas[2]
Distance335 ± 1 ly
(102.7 ± 0.4 pc)
Absolute magnitude (MV)+6.55[10]
Details
Mass0.65[11] M
Radius0.65±0.09[12] R
Luminosity0.29[13] L
Surface gravity (log g)4.50[13] cgs
Temperature5,111[14] K
Metallicity [Fe/H]+0.09±0.15[15] dex
Rotational velocity (v sin i)39±3[16] km/s
Age12.7[17] Myr
Other designations
T Cha, HIP 58285, TYC 9419-1187-1, GSC 09419-01187, 2MASS J11571348-7921313
Database references
SIMBADdata

History

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The object was first suspected to be a RW Aurigae-type star since 1949.[18] It was categorized as a T-Tauri star in 1975. In the same year, it was suspected to be variable and the variability was confirmed in 1976.[19] A 1993 paper said that it might be a weak-lined YY Orionis star.[20] T Cha might be either a member of the young ε Chamaeleontis association or the slightly older η Chamaeleontis association.[17][9] T Cha is an Orion variable that fluctuates between 10.05 and 14.5.[3][8]

Physical characteristics

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T Cha has a stellar classification of K0e,[5] indicating that it is a K-type star with emission lines in its spectrum. It is currently on the T Tauri stage,[4] accreting matter at a rate of 3.16×10−9 to 1.26×10−8 M/yr.[21] It has 65% the mass of the Sun[11] but the radius is highly uncertain. Estimates range from 0.65 to 4.36 times the radius of the Sun.[22][12] It radiates 29% the luminosity of the Sun[13] from its photosphere at an effective temperature of 5,111 K,[14] giving it an orange hue. T Cha has a poorly constrained metallicity of [Fe/H] = +0.09[15] and it spins modestly with a projected rotational velocity of 39 km/s.[16]


References

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  1. ^ "Download Data". aavso.org. AAVSO. Retrieved 1 October 2021.
  2. ^ a b c d e 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.
  3. ^ a b c "VSX : Detail for T Cha". Retrieved 2023-01-08.
  4. ^ a b Mauder, H.; Sosna, F. M. (1975). "Light Changes of T Tauri Stars in the Chamaeleon Association". Information Bulletin on Variable Stars. 1049: 1. Bibcode:1975IBVS.1049....1M.
  5. ^ a b Torres, C. A. O.; Quast, G. R.; da Silva, L.; de la Reza, R.; Melo, C. H. F.; Sterzik, M. (12 September 2006). "Search for associations containing young stars (SACY). I. Sample and searching method". Astronomy & Astrophysics. 460 (3): 695–708. arXiv:astro-ph/0609258. Bibcode:2006A&A...460..695T. doi:10.1051/0004-6361:20065602. eISSN 1432-0746. ISSN 0004-6361. S2CID 16080025.
  6. ^ a b Bastian, U.; Mundt, R. (1979). "UBV photometry of T Tauri stars and related objects". Astronomy and Astrophysics Supplement Series. 36: 57. Bibcode:1979A&AS...36...57B. ISSN 0365-0138. S2CID 118968842.
  7. ^ Glass, I. S.; Pension, M. V. (1 May 1974). "An Infrared Survey of RW Aurigae Stars". Monthly Notices of the Royal Astronomical Society. 167 (2): 237–249. Bibcode:1974MNRAS.167..237G. doi:10.1093/mnras/167.2.237. eISSN 1365-2966. ISSN 0035-8711. S2CID 120222716.
  8. ^ a b Samus’, N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (January 2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports. 61 (1): 80–88. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. eISSN 1562-6881. ISSN 1063-7729. S2CID 125853869.
  9. ^ a b c Zúñiga-Fernández, S.; Bayo, A.; Elliott, P.; Zamora, C.; Corvalán, G.; Haubois, X.; Corral-Santana, J. M.; Olofsson, J.; Huélamo, N.; Sterzik, M. F.; Torres, C. A. O.; Quast, G. R.; Melo, C. H. F. (24 December 2020). "Search for associations containing young stars (SACY)". Astronomy & Astrophysics. 645: A30. arXiv:2010.08575. Bibcode:2021A&A...645A..30Z. doi:10.1051/0004-6361/202037830. eISSN 1432-0746. ISSN 0004-6361. S2CID 239745123.
  10. ^ a b Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. eISSN 1562-6873. ISSN 1063-7737. S2CID 119257644.
  11. ^ a b Baron, Frédérique; Lafrenière, David; Artigau, Étienne; Gagné, Jonathan; Rameau, Julien; Delorme, Philippe; Naud, Marie-Eve (17 October 2019). "Constraints on the Occurrence and Distribution of 1–20 M Jup Companions to Stars at Separations of 5–5000 au from a Compilation of Direct Imaging Surveys". The Astronomical Journal. 158 (5): 187. arXiv:1909.06255. Bibcode:2019AJ....158..187B. doi:10.3847/1538-3881/ab4130. eISSN 1538-3881. S2CID 202572902.
  12. ^ a b Stassun, Keivan G.; et al. (9 September 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. eISSN 1538-3881. hdl:1721.1/124721. S2CID 166227927.
  13. ^ a b c Sartori, M. J.; Lépine, J. R. D.; Dias, W. S. (June 2003). "Formation scenarios for the young stellar associations between galactic longitudes l = 280° - 360°". Astronomy & Astrophysics. 404 (3): 913–926. arXiv:astro-ph/0304426. Bibcode:2003A&A...404..913S. doi:10.1051/0004-6361:20030581. eISSN 1432-0746. ISSN 0004-6361. S2CID 17411999.
  14. ^ a b da Silva, L.; Torres, C. A. O.; de la Reza, R.; Quast, G. R.; Melo, C. H. F.; Sterzik, M. F. (8 October 2009). "Search for associations containing young stars (SACY)". Astronomy & Astrophysics. 508 (2): 833–839. arXiv:0909.0677. Bibcode:2009A&A...508..833D. doi:10.1051/0004-6361/200911736. eISSN 1432-0746. ISSN 0004-6361.
  15. ^ a b Bochanski, John J.; Faherty, Jacqueline K.; Gagné, Jonathan; Nelson, Olivia; Coker, Kristina; Smithka, Iliya; Desir, Deion; Vasquez, Chelsea (12 March 2018). "Fundamental Properties of Co-moving Stars Observed byGaia". The Astronomical Journal. 155 (4): 149. arXiv:1801.00537. Bibcode:2018AJ....155..149B. doi:10.3847/1538-3881/aaaebe. eISSN 1538-3881.
  16. ^ a b Covino, E.; Alcala, J. M.; Allain, S.; Bouvier, J.; Terranegra, L.; Krautter, J. (1997). "A study of the Chamaeleon star-forming region from the ROSAT all-sky survey. III. High resolution spectroscopic study". Astronomy and Astrophysics. 328: 187. Bibcode:1997A&A...328..187C. ISSN 0004-6361.
  17. ^ a b Murphy, Simon J.; Lawson, Warrick A.; Bessell, Michael S. (20 August 2013). "Re-examining the membership and origin of the ϵ Cha association". Monthly Notices of the Royal Astronomical Society. 435 (2): 1325–1349. arXiv:1305.4177. Bibcode:2013MNRAS.435.1325M. doi:10.1093/mnras/stt1375. eISSN 1365-2966. ISSN 0035-8711. S2CID 55556494.
  18. ^ Hoffmeister, C. (1949). "Die RW Aurigae'Sterne und ihre Nebenformen". Astronomische Nachrichten (in German). 278 (1): 24–40. Bibcode:1949AN....278...24H. doi:10.1002/asna.19492780102. eISSN 1521-3994. ISSN 0004-6337. S2CID 122025222.
  19. ^ Glasby, J. S. (1976). "The nebular variables". Journal of the British Astronomical Association. 86: 344. Bibcode:1976JBAA...86..344G.
  20. ^ Alcala, J. M.; Covino, E.; Franchini, M.; Krautter, J.; Terranegra, L.; Wichmann, R. (May 1993). "T Chamaeleontis : A "weak-line" YY Orionis star ?". Astronomy and Astrophysics. 272: 225. Bibcode:1993A&A...272..225A. S2CID 122408037.
  21. ^ Cahill, Eoin; Whelan, Emma T; Huelamo, Nuria; Alcala, Juan (28 January 2019). "UVES Spectroscopy of T Chamaeleontis: Line Variability, Mass Accretion rate and Spectro-astrometric Analysis★". Monthly Notices of the Royal Astronomical Society. 484 (3): 4315. arXiv:1902.01170. Bibcode:2019MNRAS.484.4315C. doi:10.1093/mnras/stz280. eISSN 1365-2966. ISSN 0035-8711. S2CID 118944630.
  22. ^ Kervella, P.; Thévenin, F.; Di Folco, E.; Ségransan, D. (October 2004). "The angular sizes of dwarf stars and subgiants. Surface brightness relations calibrated by interferometry". Astronomy & Astrophysics. 426 (1): 297–307. arXiv:astro-ph/0404180. Bibcode:2004A&A...426..297K. doi:10.1051/0004-6361:20035930. eISSN 1432-0746. ISSN 0004-6361. S2CID 6077801.