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]
| 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] |
| Distance | 205 ± 4 ly (63 ± 1 pc) |
| Absolute magnitude (MV) | 1.15[2] |
| Details | |
| λ CrA A | |
| Mass | 2.17±0.10[2] M☉ |
| Radius | 2.24[2] R☉ |
| Luminosity | 31.25[6] L☉ |
| Surface gravity (log g) | 4.08±0.08[2] cgs |
| Temperature | 8,609[8] K |
| Metallicity [Fe/H] | −0.30[8] dex |
| Rotational velocity (v sin i) | 148.6±1.6[9] km/s |
| Age | 273[10] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
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]