LQ Andromedae

LQ Andromedae

A visual band light curve for LQ Andromedae, adapted from Harmanec et al. (1991)[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Andromeda
Right ascension 23h 58m 46.4391s[2]
Declination +46° 24′ 47.44272″[2]
Apparent magnitude (V) 6.50 – 6.66 variable[3]
Characteristics
Spectral type B4Ven[3]
Apparent magnitude (U) 5.84[4]
Apparent magnitude (B) 6.444[5]
Apparent magnitude (V) 6.538[5]
Apparent magnitude (G) 6.4666[2]
Apparent magnitude (J) 6.588[6]
Apparent magnitude (H) 6.617[6]
Apparent magnitude (K) 6.545[6]
B−V color index 0.098[7]
Variable type Be star
Astrometry
Radial velocity (Rv)−51.27±0.42[8] km/s
Proper motion (μ) RA: 15.419±0.081 [2] mas/yr
Dec.: 0.574±0.060[2] mas/yr
Parallax (π)2.4169 ± 0.0519 mas[2]
Distance1,350 ± 30 ly
(414 ± 9 pc)
Orbit
Period (P)7.413 days[9]
Details[7]
Mass7±1[10] M☉
Radius4.8±0.6[10] R☉
Luminosity (bolometric)2,559 L☉
Surface gravity (log g)3.49±0.37 cgs
Temperature17260±520 K
Rotational velocity (v sin i)300±25 km/s
Other designations
2MASS J23584644+4624474, BD+45 4381, HD 224559, HIP 118214, HR 9070, SAO 53540, TYC 3639-164-1
Database references
SIMBADdata

LQ Andromedae (shortened as LQ And, also known as HR 9070 in the Bright Star Catalogue) is a variable star in the constellation Andromeda. Its maximum apparent visual magnitude is 6.5, placing it at the limit of the visibility to the naked eye. The brightness, however, drops down to 6.66 with a periodic cycle of roughly 7.44 hours.[3]

The stellar classification of this star is B4Ven,[3] so it is a main sequence star that shows emission lines and broadened absorption lines induced by the fast projected rotational velocity of 300 km/s (the angle between the rotation axis and our line of sight has been estimated with a value of 72°).[7] This leads to the classification of the star as a Be star. Further proof is the compatibility between the rotational and luminosity variability periods.[9]

LQ Andromedae is also a spectroscopic binary with an orbital period of 7.413 days. Not much is known about the secondary component, but it is likely a low-mass companion (M<0.5 M☉). A circumstellar disk is also present in the system.[9]

  1. ^ Cite error: The named reference Harmanec was invoked but never defined (see the help page).
  2. ^ a b c d e f 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.
  3. ^ a b c d Cite error: The named reference GCVS was invoked but never defined (see the help page).
  4. ^ "LQ And". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved October 18, 2018.
  5. ^ a b Cite error: The named reference TYCHO was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference 2MASS Cat was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference Zorec2016 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference rv was invoked but never defined (see the help page).
  9. ^ a b c Cite error: The named reference Matthews1991 was invoked but never defined (see the help page).
  10. ^ a b Vieira, R. G.; Carciofi, A. C.; Bjorkman, J. E.; Rivinius, Th.; Baade, D.; Rímulo, L. R. (2017). "The life cycles of be viscous decretion discs: Time-dependent modelling of infrared continuum observations". Monthly Notices of the Royal Astronomical Society. 464 (3): 3071–3089. arXiv:1707.02861. doi:10.1093/mnras/stw2542.