Lambda Coronae Australis

Lambda Coronae Australis
Observation data
Epoch J2000      Equinox J2000
Constellation Corona Australis
Right ascension 18h 43m 46.94143s[1]
Declination −38° 19′ 24.3941″[1]
Apparent magnitude (V) 5.11[2] + 10.01[3]
Characteristics
Spectral type A0/1V[4] + K0[5]
B−V color index +0.075±0.002[6]
Astrometry
Radial velocity (Rv)−26.40±4.2[7] km/s
Proper motion (μ) RA: +1.047[1] mas/yr
Dec.: −53.774[1] mas/yr
Parallax (π)15.8771 ± 0.2823 mas[1]
Distance205 ± 4 ly
(63 ± 1 pc)
Absolute magnitude (MV)1.15[2]
Details
λ CrA A
Mass2.17±0.10[2] M☉
Radius2.24[2] R☉
Luminosity31.25[6] L☉
Surface gravity (log g)4.08±0.08[2] cgs
Temperature8,609[8] K
Metallicity [Fe/H]−0.30[8] dex
Rotational velocity (v sin i)148.6±1.6[9] km/s
Age273[10] Myr
Other designations
λ CrA, CD−38°13036, HD 172777, HIP 91875, HR 7021, SAO 210501, WDS J18438-3819A[11]
Database references
SIMBADdata

λ Coronae Australis, Latinized as Lambda Coronae Australis is a binary star[5] system located in the southern constellation of Corona Australis. It is visible to the naked eye as a faint, white-hued point of light with an apparent visual magnitude of 5.11.[2] The system is located at a distance of 205 light-years, based on parallax,[1] and is drifting further away with a radial velocity of −26 km/s.[7]

The primary member of this system, designated component A, is an A-type main-sequence star with a stellar classification of A0/1V.[4] It is 273[10] million years old and is spinning with a projected rotational velocity of 149 km/s.[9] This high rotation rate is producing an equatorial bulge that is 7% larger than the polar radius.[12] It has 2.17 times the mass of the Sun and 2.24 times the Sun's radius.[2] The star is radiating 31[6] times the Sun's luminosity from its photosphere at an effective temperature of 8,609 K.[8]

The secondary companion, component B,[13] has an apparent visual magnitude of 10.01[3] and a class of K0.[5] As of 2016, it has an angular separation of 29.5″ from the primary along a position angle of 213°.[3] Component C[14] is a visual companion of magnitude 9.9 and separation 43.3″ from the primary.[3]

  1. ^ a b c d e f Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c d e f g Cite error: The named reference AllendePrieto was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference WDSC2014 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Houk1988 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  8. ^ a b c Cite error: The named reference Erspamer2003 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Díaz2011 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference David2015 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference SIMBADA was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference vanBelle2012 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference SIMBADB was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference SIMBADC was invoked but never defined (see the help page).