Astronomy:Epsilon Muscae

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Short description: Variable star in the constellation Musca
Epsilon Muscae
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A light curve for Epsilon Muscae, plotted from Hipparcos data[1]
Observation data
Equinox J2000.0]] (ICRS)
Constellation Musca[2]
Right ascension  12h 17m 34.27564s[3]
Declination −67° 57′ 38.6525″[3]
Apparent magnitude (V) 4.0 – 4.3[4]
Characteristics
Evolutionary stage asymptotic giant branch[5]
Spectral type M5 III[6]
Variable type SRb[4]
Astrometry
Radial velocity (Rv)7.1±0.7[7] km/s
Proper motion (μ) RA: −230.607±0.187[3] mas/yr
Dec.: −26.206±0.263[3] mas/yr
Parallax (π)9.9915 ± 0.2[3] mas
Distance326 ± 7 ly
(100 ± 2 pc)
Absolute magnitude (MV)−0.77[2]
Details
Mass2±0.3[8] M
Radius116±9[8] R
Luminosity1,738[3] L
Surface gravity (log g)0.6±0.02[8] cgs
Temperature3,470±125[8] K
Other designations
eps Mus, CPD−67 1931, HD 106849, HIP 59929, HR 4671, SAO 251830
Database references
SIMBADdata

Epsilon Muscae, Latinized as ε Muscae, is a red giant star of spectral type M5III in the constellation Musca.[6] It is a 4th magnitude star, visible to the naked eye under good observing conditions. It is about 330 light-years from the Earth.[3]

Originally a main-sequence star of around 2 solar masses,[8] Epsilon Muscae is now on the asymptotic giant branch[5] and has expanded to 117 times the Sun's diameter and 1,700 its luminosity.[8] It is a semiregular variable, varying between visual magnitudes 4.0 and 4.3[4] in eight distinct periods ranging from a month to over half a year in length.[6] Its distance from the Earth is about the same as the Lower Centaurus–Crux subgroup of the Scorpius–Centaurus association, although it is moving much faster at around 100 km/s and does not share a common origin.[9]

References

  1. "/ftp/cats/more/HIP/cdroms/cats". Strasbourg astronomical Data Center. https://cdsarc.cds.unistra.fr/viz-bin/ftp-index?/ftp/cats/more/HIP/cdroms/cats. 
  2. 2.0 2.1 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode2012AstL...38..331A  XHIP record for this object at VizieR.
  3. 3.0 3.1 3.2 3.3 3.4 3.5 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.
  4. 4.0 4.1 4.2 Samus, N. N. et al. (2017). "General Catalogue of Variable Stars". Astronomy Reports. 5.1 61 (1): 80–88. doi:10.1134/S1063772917010085. Bibcode2017ARep...61...80S. 
  5. 5.0 5.1 Eggen, Olin J. (July 1992). "Asymptotic giant branch stars near the sun". Astronomical Journal 104 (1): 275–313. doi:10.1086/116239. Bibcode1992AJ....104..275E. 
  6. 6.0 6.1 6.2 "Long-term photometry and periods for 261 nearby pulsating M giants". Monthly Notices of the Royal Astronomical Society 400 (4): 1945–1961. 2009. doi:10.1111/j.1365-2966.2009.15588.x. Bibcode2009MNRAS.400.1945T. 
  7. Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759. doi:10.1134/S1063773706110065. Bibcode2006AstL...32..759G. 
  8. 8.0 8.1 8.2 8.3 8.4 8.5 Kallinger, T.; Beck, P. G.; Hekker, S.; Huber, D.; Kuschnig, R.; Rockenbauer, M.; Winter, P. M.; Weiss, W. W. et al. (2019-04-01). "Stellar masses from granulation and oscillations of 23 bright red giants observed by BRITE-Constellation" (in en). Astronomy & Astrophysics 624: A35. doi:10.1051/0004-6361/201834514. ISSN 0004-6361. Bibcode2019A&A...624A..35K. 
  9. "Error: no |title= specified when using {{Cite web}}". Stars. University of Illinois. http://stars.astro.illinois.edu/sow/epsmus.html. Retrieved 21 December 2013.