The star system AK Scorpii imaged by ALMA. The Binary star orbit was added for clarity. Credit: ALMA (ESO/NAOJ/NRAO), I. Czekala and G. Kennedy; NRAO/AUI/NSF, S. Dagnello | |
Observation data Epoch J2000.0 Equinox J2000.0 | |
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Constellation | Scorpius |
Right ascension | 16h 54m 44.8498s[1] |
Declination | −36° 53′ 18.561″[1] |
Apparent magnitude (V) | 9.00 |
Characteristics | |
Spectral type | F 5 IV-V[2] |
Apparent magnitude (G) | 9.2823 ± 0.0223[1] |
Variable type | Herbig Ae/Be star[2] |
Astrometry | |
Radial velocity (Rv) | -1.97 ± 0.5[3] km/s |
Proper motion (μ) | RA: −8.399±0.116[1] mas/yr Dec.: −29.268±0.083[1] mas/yr |
Parallax (π) | 7.1126 ± 0.0621 mas[1] |
Distance | 459 ± 4 ly (141 ± 1 pc) |
Orbit[3][4] | |
Primary | AK Scorpii A |
Companion | AK Scorpii B |
Period (P) | 13.609 ± 0.001 days |
Semi-major axis (a) | 0.16 au |
Eccentricity (e) | 0.47 ± 0.01 |
Inclination (i) | 115 ± 3° |
Longitude of the node (Ω) | 48 ± 3° |
Argument of periastron (ω) (secondary) | 186 ± 2° |
Semi-amplitude (K1) (primary) | 64.7 ± 0.9 km/s |
Semi-amplitude (K2) (secondary) | 65.5 ± 0.9 km/s |
Details[4] | |
AK Scorpii A | |
Mass | 1.25 M☉ |
Age | 18 Myr |
AK Scorpii B | |
Mass | 1.25 M☉ |
Age | 18 Myr |
Other designations | |
Database references | |
SIMBAD | AB |
AK Scorpii is a Herbig Ae/Be star[2] and spectroscopic binary star about 459 light-years distant in the constellation Scorpius. The star belongs to the nearby Upper Centaurus–Lupus star-forming region and the star is actively accreting material.[5] The binary is surrounded by a circumbinary disk that was imaged with VLT/SPHERE in scattered light[6] and with ALMA.[4]