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R Leporis

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R Leporis (R Lep), sometimes called Hind's Crimson Star,[10] is a well-known variable star in the constellation Lepus, near its border with Eridanus.

R Leporis

Location of R Leporis in the constellation Lepus.
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Lepus
Right ascension 04h 59m 36.3487s[1]
Declination −14° 48′ 22.518″[1]
Apparent magnitude (V) 5.5 to 11.7[2]
Characteristics
Spectral type C7,6e(N6e)[2]
B−V color index +5.74[3]
R−I color index +1.47[3]
Variable type Mira[2]
Astrometry
Radial velocity (Rv)32.4 ± 2[1] km/s
Proper motion (μ) RA: 6.798 mas/yr[4]
Dec.: −1.263 mas/yr[4]
Parallax (π)2.1914 ± 0.0602 mas[4]
Distance1,490 ± 40 ly
(460 ± 10 pc)
Details
Mass1.00[5] – 2.02[6] M☉
Radius645 – 860[7] R☉
Luminosity13,200[8] L☉
Surface gravity (log g)−0.6[6] cgs
Temperature2,290[9] K
Metallicity [Fe/H]−0.409[6] dex
Other designations
R Lep, AAVSO 0455-14, BD−15 915, GC 6093, HD 31996, HIP 23203, HR 1607, IRC -10080, PPM 215123, RAFGL 667, SAO 150058.[1]
Database references
SIMBADdata

It is a carbon star which appears distinctly red. It is named after famous British astronomer J. R. Hind, who observed it in 1845. Its apparent magnitude varies from +5.5 to +11.7 with a period of 418–441 days; recent measurements give a period of 427.07 days. There may be a secondary period of 40 years.[3] Guandalini and Cristallo calculated the luminosity of Mira variables based on their periods. Using a period of 427.07 days, they calculated the bolometric luminosity to be 13,200 L☉.[8]

R Leporis has often been reported as an intense smoky red color, although this is not pronounced when the star is near its maximum brightness. It is reddest when it is dimmest, which occurs every 14.5 months. During these periods it is a candidate for the most-visible reddest star, but this claim is questionable. The red coloration may be caused by carbon in the star's outer atmosphere filtering out the blue part of its visible light spectrum. The star's discoverer, Hind, reported that it appeared "like a drop of blood on a black field."[10]

  • R Leporis as imaged by ALMA[11]
    R Leporis as imaged by ALMA[11]
  • An image of the carbon star R Leporis as seen in binoculars. R Leporis is the red star right of centre. The bright star in the lower left corner is Mu Leporis.
    An image of the carbon star R Leporis as seen in binoculars. R Leporis is the red star right of centre. The bright star in the lower left corner is Mu Leporis.
  • The light curve of R Leporis from AAVSO V band data[12]
    The light curve of R Leporis from AAVSO V band data[12]

References

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  1. ^ a b c d "R Leporis". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved November 19, 2009.
  2. ^ a b c R Lep, database entry, The combined table of GCVS Vols I-III and NL 67-78 with improved coordinates, General Catalogue of Variable Stars Archived 2017-06-20 at the Wayback Machine, Sternberg Astronomical Institute, Moscow, Russia. Accessed on line November 19, 2009.
  3. ^ a b c HR 1607, database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50. Accessed on line November 19, 2009.
  4. ^ a b 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.
  5. ^ Rau, G.; Hron, J.; Paladini, C.; Aringer, B.; Eriksson, K.; Marigo, P.; Nowotny, W.; Grellmann, R. (2017-04-01). "The adventure of carbon stars. Observations and modeling of a set of C-rich AGB stars". Astronomy and Astrophysics. 600: A92. arXiv:1701.04331. Bibcode:2017A&A...600A..92R. doi:10.1051/0004-6361/201629337. ISSN 0004-6361.
  6. ^ a b c Anders, F.; Khalatyan, A.; Queiroz, A. B. A.; Chiappini, C.; Ardèvol, J.; Casamiquela, L.; Figueras, F.; Jiménez-Arranz, Ó.; Jordi, C.; Monguió, M.; Romero-Gómez, M.; Altamirano, D.; Antoja, T.; Assaad, R.; Cantat-Gaudin, T. (2022-02-01). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia EDR3 stars brighter than G = 18.5". Astronomy and Astrophysics. 658: A91. arXiv:2111.01860. Bibcode:2022A&A...658A..91A. doi:10.1051/0004-6361/202142369. ISSN 0004-6361. Database at VizieR.
  7. ^ Asaki, Yoshiharu; Maud, Luke T.; Francke, Harold; Nagai, Hiroshi; Petry, Dirk; Fomalont, Edward B.; Humphreys, Elizabeth; Richards, Anita M. S.; Wong, Ka Tat; Dent, William; Hirota, Akihiko; Fernandez, Jose Miguel; Takahashi, Satoko; Hales, Antonio S. (November 2023). "ALMA High-frequency Long Baseline Campaign in 2021: Highest Angular Resolution Submillimeter Wave Images for the Carbon-rich Star R Lep". The Astrophysical Journal. 958 (1): 86. arXiv:2310.09664. Bibcode:2023ApJ...958...86A. doi:10.3847/1538-4357/acf619. ISSN 0004-637X.
  8. ^ a b Guandalini, R.; Cristallo, S. (2013). "Luminosities of carbon-rich asymptotic giant branch stars in the Milky Way". Astronomy & Astrophysics. 555: 7. arXiv:1305.4203. Bibcode:2013A&A...555A.120G. doi:10.1051/0004-6361/201321225. S2CID 54918450. A120.
  9. ^ Lombaert, R.; Decin, L.; Royer, P.; De Koter, A.; Cox, N. L. J.; González-Alfonso, E.; Neufeld, D.; De Ridder, J.; Agúndez, M.; Blommaert, J. A. D. L.; Khouri, T.; Groenewegen, M. A. T.; Kerschbaum, F.; Cernicharo, J.; Vandenbussche, B.; Waelkens, C. (2016). "Constraints on the H2O formation mechanism in the wind of carbon-rich AGB stars". Astronomy & Astrophysics. 588: A124. arXiv:1601.07017. Bibcode:2016A&A...588A.124L. doi:10.1051/0004-6361/201527049. S2CID 62787287.
  10. ^ a b Richard Hinckley Allen (1899). Star-names and Their Meanings. New York: G.E. Stechert. p. 269.
  11. ^ "ALMA achieves its highest resolution observations". www.eso.org. Retrieved 15 November 2023.
  12. ^ "Download Data". aavso.org. AAVSO. Retrieved 1 October 2021.
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