II Lupi

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II Lupi
IILupLightCurve.png
A near-infrared (J band) light curve for II Lupi, adapted from Lykou et al. (2018)[1]
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Lupus
Right ascension 15h 23m 05.075s[2]
Declination −51° 25′ 58.73″[2]
Characteristics
Spectral type C[3]
Apparent magnitude (I) 10.18[4]
Apparent magnitude (J) 5.92[5]
Apparent magnitude (K) 1.79[5]
Variable type Mira[6]
Astrometry
Proper motion (μ) RA: −13.837[7] mas/yr
Dec.: 5.415[7] mas/yr
Parallax (π)0.5217 ± 0.2778[7] mas
Distance500[8] pc
Absolute magnitude (MV)−5.15[9]
Details
Radius547[3] R☉
Luminosity8,800[8] L☉
Temperature2,400[8] K
Other designations
II Lup, IRAS 15194-5115, 2MASS J15230507-5125587, WOS 48, Gaia DR2 5889797405925371392
Database references
SIMBADdata

II Lupi (IRAS 15194-5115) is a Mira variable and carbon star located in the constellation Lupus. It is the brightest carbon star in the Southern Hemisphere at 12 μm.

In 1987, the infrared source IRAS 15194-5115 was identified as an extreme carbon star. It was seen to be strongly variable at optical and infrared wavelengths. It is very faint visually, 15th or 16th magnitude in a red filter and below 21st magnitude in a blue filter, but at mid-infrared wavelengths (N band) it is the third-brightest carbon star in the sky.[10] A star at the location had earlier been catalogued as WOS 48, a possible S-type star, on the basis of strong LaO bands in its spectrum.[11]

On the basis of infrared photometry,[12] IRAS 15194-5115 was given the variable star designation II Lupi in 1995, although the variability type was still unknown.[13] More detailed infrared photometry confirmed that II Lupi was a Mira variable and showed regular variations with a period of 575 days over 18 years. The mean magnitude also dimmed and brightened during that time and has been characterised as a 6,900-day secondary period although less than a full cycle was observed. The secondary period could be interpreted as an isolated or irregular obscuration event in a dust shell surrounding the star.[14]

II Lupi has a strong stellar wind averaging 10−5 solar masses per year.[15]

References[]

  1. ^ Lykou, Foteini; Zijlstra, A. A.; Kluska, J.; Lagadec, E.; Tuthill, P. G.; Avison, A.; Norris, B. R. M.; Parker, Q. A. (October 2018). "The curious case of II Lup: a complex morphology revealed with SAM/NACO and ALMA". Monthly Notices of the Royal Astronomical Society. 480 (1): 1006–1021. doi:10.1093/mnras/sty1903. Retrieved 21 January 2022.
  2. ^ a b Cutri, Roc M.; Skrutskie, Michael F.; Van Dyk, Schuyler D.; Beichman, Charles A.; Carpenter, John M.; Chester, Thomas; Cambresy, Laurent; Evans, Tracey E.; Fowler, John W.; Gizis, John E.; Howard, Elizabeth V.; Huchra, John P.; Jarrett, Thomas H.; Kopan, Eugene L.; Kirkpatrick, J. Davy; Light, Robert M.; Marsh, Kenneth A.; McCallon, Howard L.; Schneider, Stephen E.; Stiening, Rae; Sykes, Matthew J.; Weinberg, Martin D.; Wheaton, William A.; Wheelock, Sherry L.; Zacarias, N. (2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". CDS/ADC Collection of Electronic Catalogues. 2246: II/246. Bibcode:2003yCat.2246....0C. S2CID 115529446.
  3. ^ a b De Beck, E.; Decin, L.; De Koter, A.; Justtanont, K.; Verhoelst, T.; Kemper, F.; Menten, K. M. (2010). "Probing the mass-loss history of AGB and red supergiant stars from CO rotational line profiles. II. CO line survey of evolved stars: Derivation of mass-loss rate formulae". Astronomy and Astrophysics. 523: A18. arXiv:1008.1083. Bibcode:2010A&A...523A..18D. doi:10.1051/0004-6361/200913771. S2CID 16131273.
  4. ^ DENIS Consortium (2003). "VizieR Online Data Catalog: The DENIS database (DENIS Consortium, 2003)". VizieR On-line Data Catalog. Bibcode:2003yCat....102002T.
  5. ^ a b Whitelock, Patricia A; Feast, Michael W; Marang, Freddy; Groenewegen, M. A. T (2006). "Near-infrared photometry of carbon stars". Monthly Notices of the Royal Astronomical Society. 369 (2): 751–782. arXiv:astro-ph/0603504. Bibcode:2006MNRAS.369..751W. doi:10.1111/j.1365-2966.2006.10322.x. S2CID 14453496.
  6. ^ 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.
  7. ^ a b c Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  8. ^ a b c Schöier, F. L; Ramstedt, S; Olofsson, H; Lindqvist, M; Bieging, J. H; Marvel, K. B (2013). "The abundance of HCN in circumstellar envelopes of AGB stars of different chemical type". Astronomy & Astrophysics. 550: A78. arXiv:1301.2129. Bibcode:2013A&A...550A..78S. doi:10.1051/0004-6361/201220400. S2CID 96447896.
  9. ^ Guandalini, R; Cristallo, S (2013). "Luminosities of carbon-rich asymptotic giant branch stars in the Milky Way". Astronomy & Astrophysics. 555: A120. arXiv:1305.4203. Bibcode:2013A&A...555A.120G. doi:10.1051/0004-6361/201321225. S2CID 54918450.
  10. ^ Meadows, P. J; Good, A. R; Wolstencroft, R. D (1987). "The identification of IRAS 15194-5115 with a bright extreme carbon star". Monthly Notices of the Royal Astronomical Society. 225: 43p–49p. Bibcode:1987MNRAS.225P..43M. doi:10.1093/mnras/225.1.43P.
  11. ^ Westerlund, B. E; Olander, N (1978). "S stars in the southern Milky Way". Astronomy and Astrophysics Supplement Series. 32: 401. Bibcode:1978A&AS...32..401W.
  12. ^ Le Bertre, T (1992). "Carbon-star lightcurves in the 1-20 micron range". Astronomy and Astrophysics Supplement Series. 94: 377. Bibcode:1992A&AS...94..377L.
  13. ^ Kazarovets, E. V; Samus, N. N (1995). "The 72nd Name-List of Variable Stars". Information Bulletin on Variable Stars. 4140: 1. Bibcode:1995IBVS.4140....1K.
  14. ^ Feast, Michael W; Whitelock, Patricia A; Marang, Freddy (2003). "The case for asymmetric dust around a C-rich asymptotic giant branch star". Monthly Notices of the Royal Astronomical Society. 346 (3): 878. arXiv:astro-ph/0308417. Bibcode:2003MNRAS.346..878F. doi:10.1111/j.1365-2966.2003.07136.x. S2CID 18362625.
  15. ^ Smith, C. L.; Zijlstra, A. A.; Fuller, G. A. (2015), "A molecular line survey of a sample of AGB stars and planetary nebulae", Monthly Notices of the Royal Astronomical Society, 454 (1): 177–200, arXiv:1508.05014, Bibcode:2015MNRAS.454..177S, doi:10.1093/mnras/stv1934, S2CID 119294505
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