Eta Muscae

Eta Muscae

A light curve for Eta Muscae plotted from TESS data[1]
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Musca
Right ascension 13h 15m 14.94123s[2]
Declination −67° 53′ 40.5276″[2]
Apparent magnitude (V) 4.79[3]
Characteristics
Spectral type B8V + sim. + K9.4XR? + A0p[4] or B7III + B7III[5]
B−V color index −0.078±0.003[3]
Variable type eclipsing binary
Astrometry
Radial velocity (Rv)−8.1±7.4[3] km/s
Proper motion (μ) RA: +30.207[2] mas/yr
Dec.: +17.921[2] mas/yr
Parallax (π)7.1001 ± 0.1924 mas[2]
Distance405.7[6] ly
(124.4[6] pc)
Absolute magnitude (MV)−0.81[6]
Orbit[7]
Period (P)2.3963161 d
Semi-major axis (a)14.11±0.15 R☉
Eccentricity (e)0.00
Inclination (i)77.40°
Semi-amplitude (K1)
(primary)		145.35±0.20 km/s
Semi-amplitude (K2)
(secondary)		145.38±0.20 km/s
Details[7]
Eta Mus Aa
Mass3.30±0.04 M☉
Radius2.14±0.02 R☉
Luminosity223.77[3] (combined) L☉
Surface gravity (log g)4.293±0.005 cgs
Temperature12,700±100 K
Rotational velocity (v sin i)34±2 km/s
Eta Mus Ab
Mass3.29±0.04 M☉
Radius2.13±0.04 R☉
Surface gravity (log g)4.298±0.005 cgs
Temperature12,550±300 K
Rotational velocity (v sin i)44±2 km/s
Other designations
η Mus, CPD−67° 2224, FK5 493, HD 114911, HIP 64661, HR 4993, SAO 252224, WDS J13152-6754A[8]
Database references
SIMBADdata

Eta Muscae is a multiple[9][10] star system in the southern constellation of Musca. It is visible to the naked eye as a faint, blue-white hued point of light with an apparent visual magnitude of 4.79.[3] The system is located around 406 light years away from the Sun.[6] It is a member of the Lower Centaurs Crux subgroup of the Sco OB2 stellar association of co-moving stars.[11]

The two main components of this system form a double-lined spectroscopic binary[12] with a period of 2.4 days in a circular orbit.[7][11] They are a detached eclipsing binary with a spectral type of B8V and a brightness that dips by 0.05 magnitude once per orbit.[13] This pair consists of two components of similar mass and type.[4]

Further away from the primary system are stars of magnitude 7.3 and 10, designated Eta Muscae B and C. It is unclear if these stars are gravitationally–bound to the main pair. Evidence for an additional component has been found with a 30-year cycle in the orbital behavior of the main pair.[9] The data suggests an orbital eccentricity of 0.29 for this suspected component, Eta Muscae D.[14]

  1. ^ Cite error: The named reference MAST was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  3. ^ a b c d e Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Hube1970 was invoked but never defined (see the help page).
  6. ^ a b c d Cite error: The named reference Hubrig2001 was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference Eker2014 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Butland2011 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Medici2000 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference Hensberge2003 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Buscombe1961 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Zasche09 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Blackford2016 was invoked but never defined (see the help page).