Astronomy:8 Leonis Minoris

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Short description: Star in the constellation of Leo Minor
8 Leonis Minoris
Leo Minor constellation map.svg
Red circle.svg
Location of 8 Leonis Minoris (circled)
Observation data
Epoch J2000.0   Equinox (celestial coordinates)
Constellation Leo Minor
Right ascension  09h 31m 32.41045s[1]
Declination +35° 06′ 11.7793″[1]
Apparent magnitude (V) 5.37[2]
Characteristics
Evolutionary stage AGB[3]
Spectral type M1 IIIab[4]
U−B color index +1.81[2]
B−V color index +1.53[2]
Variable type suspected[5]
Astrometry
Radial velocity (Rv)39.83±0.18[6] km/s
Proper motion (μ) RA: −54.488[1] mas/yr
Dec.: −97.434[1] mas/yr
Parallax (π)6.6271 ± 0.0238[1] mas
Distance492 ± 2 ly
(150.9 ± 0.5 pc)
Absolute magnitude (MV)−0.43[7]
Details
Mass1.59[8] M
Radius48.5[9] R
Luminosity417±17[10] L
Surface gravity (log g)1.153[11] cgs
Temperature3,978±122[12] K
Metallicity [Fe/H]−0.25[1] dex
Other designations
8 Leonis Minoris, BD+35°2015, GC 13133, HD 82198, HIP 46735, HR 3769, SAO 61450[13]
Database references
SIMBADdata

8 Leonis Minoris (8 LMi) is a solitary,[14] red hued star located in the northern constellation Leo Minor. It has an apparent magnitude 5.37,[2] making it faintly visible to the naked eye. Based on parallax measurements from the Gaia satellite, the object is estimated to be 492 light years distant.[1] It is receding with a heliocentric radial velocity of 40 km/s.[6] At its current distance, 8 LMi is diminshed by 0.12 magnitudes due to interstellar dust.[15]

This is an asymptotic giant branch star[3] with stellar classification of M1 IIIab.[4] It has 1.59 times the mass of the Sun[8] but has expanded to 48.5 times its girth.[9] It radiates 417 times the luminosity of the Sun[10] from its enlarged photosphere at an effective temperature of 3,978 K.[12] 8 LMi has an iron abundance only half of the Sun's, making it metal deficient.[1]

8 LMi's variability was first observed to be variable in 1930 by Joel Stebbins.[16] However, Eggen (1967) instead lists it as an ordinary M-type giant and used the object for comparison.[17] In 1978-9, 8 LMi was again listed as a variable star but did not provide further insight.[18] As of 2017, the star has not been confirmed to be variable.[5]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  2. 2.0 2.1 2.2 2.3 Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system.". VizieR Online Data Catalog. Bibcode2002yCat.2237....0D. 
  3. 3.0 3.1 Eggen, Olin J. (July 1992). "Asymptotic giant branch stars near the sun". The Astronomical Journal 104: 275. doi:10.1086/116239. ISSN 0004-6256. Bibcode1992AJ....104..275E. 
  4. 4.0 4.1 Yamashita, Y. (1967). "MK Spectral Types of Bright M-Type Stars". Publications of the Dominion Astrophysical Observatory Victoria 13: 44. ISSN 0078-6950. Bibcode1967PDAO...13...47Y. 
  5. 5.0 5.1 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. doi:10.1134/S1063772917010085. ISSN 1063-7729. Bibcode2017ARep...61...80S. 
  6. 6.0 6.1 Famaey, B.; Pourbaix, D.; Frankowski, A.; Van Eck, S.; Mayor, M.; Udry, S.; Jorissen, A. (18 February 2009). "Spectroscopic binaries among Hipparcos M giants". Astronomy & Astrophysics 498 (2): 627–640. doi:10.1051/0004-6361/200810698. ISSN 0004-6361. Bibcode2009A&A...498..627F. 
  7. Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331–346. doi:10.1134/S1063773712050015. ISSN 1063-7737. Bibcode2012AstL...38..331A. 
  8. 8.0 8.1 Kervella, Pierre; Arenou, Frédéric; Mignard, François; Thévenin, Frédéric (March 2019). "Stellar and substellar companions of nearby stars from Gaia DR2". Astronomy & Astrophysics 623 (4): A72. doi:10.1051/0004-6361/201834371. ISSN 0004-6361. Bibcode2019MNRAS.484.4619G. 
  9. 9.0 9.1 Kervella, Pierre; Arenou, Frédéric; Thévenin, Frédéric (20 December 2021). "Stellar and substellar companions from Gaia EDR3". Astronomy & Astrophysics 657: A7. doi:10.1051/0004-6361/202142146. ISSN 0004-6361. Bibcode2022A&A...657A...7K. 
  10. 10.0 10.1 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  11. Ghosh, Supriyo; Mondal, Soumen; Das, Ramkrishna; Khata, Dhrimadri (29 January 2019). "Spectral Calibration of K−M Giants from medium resolution near-infrared HK-band spectra". Monthly Notices of the Royal Astronomical Society 484 (4): 4619. doi:10.1093/mnras/stz299. ISSN 0035-8711. Bibcode2019MNRAS.484.4619G. 
  12. 12.0 12.1 Stassun, Keivan G. et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal 158 (4): 138. doi:10.3847/1538-3881/ab3467. Bibcode2019AJ....158..138S. 
  13. "8 Leonis Minoris". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=8+Leonis+Minoris. 
  14. Eggleton, P. P.; Tokovinin, A. A. (11 September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society 389 (2): 869–879. doi:10.1111/j.1365-2966.2008.13596.x. ISSN 0035-8711. Bibcode2008MNRAS.389..869E. 
  15. Gontcharov, George A.; Mosenkov, Aleksandr V. (28 September 2017). "Verifying reddening and extinction for Gaia DR1 TGAS main sequence stars". Monthly Notices of the Royal Astronomical Society 472 (4): 3805–3820. doi:10.1093/mnras/stx2219. ISSN 0035-8711. Bibcode2017MNRAS.472.3805G. 
  16. Stebbins, Joel; Huffer, Charles Morse (1930). "The constancy of the light of red stars". Publications of the Washburn Observatory 15: 140–174. Bibcode1930PWasO..15..140S. 
  17. Eggen, Olin J. (September 1967). "- and Broad-Band Photometry of Red Stars. Northern Giants". The Astrophysical Journal Supplement Series 14: 307. doi:10.1086/190158. ISSN 0067-0049. Bibcode1967ApJS...14..307E. 
  18. Pyl'skaja, O. P.; Zakharova, P. E.; Polushina, T. S. (December 1978). "V-R Colours of Red Variable Stars". Information Bulletin on Variable Stars 1513: 1. ISSN 0374-0676. Bibcode1978IBVS.1513....1P.