29 Aquarii is a binary star system located around 590 light years away from the Sun in the equatorial constellation of Aquarius. 29 Aquarii is the Flamsteed designation; the system also bears the variable star designation DX Aquarii. It is a challenge to view with the naked eye, appearing as a dim star with a combined apparent visual magnitude of 6.39.[3] The system is moving further from the Earth with a heliocentric radial velocity of about +15 km/s.[3]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Aquarius |
Right ascension | 22h 02m 26.24845s[2] |
Declination | −16° 57′ 53.3959″[2] |
Apparent magnitude (V) | 6.39[3] |
Characteristics | |
Spectral type | A2 V + K0 III[4] |
B−V color index | 0.447±0.022[3] |
Astrometry | |
Radial velocity (Rv) | +15.0±4.3[3] km/s |
Proper motion (μ) | RA: +5.292[2] mas/yr Dec.: +1.256[2] mas/yr |
Parallax (π) | 5.5489 ± 0.1285 mas[5] |
Distance | 590 ± 10 ly (180 ± 4 pc) |
Orbit[6] | |
Period (P) | 0.945 d |
Eccentricity (e) | 0.00 |
Periastron epoch (T) | 2,436,814.418±1.0 JD |
Semi-amplitude (K1) (primary) | 97.9 km/s |
Other designations | |
Database references | |
SIMBAD | data |
This is a spectroscopic binary system with a close circular orbit taking just 0.945 days to complete.[6] Despite their proximity, this does not appear to be a contact binary system.[8] The orbital plane of the two stars lies near the line of sight, so they form an Algol-type eclipsing binary. The first component of the system is an A-type main sequence star with a stellar classification of A2 V. Its companion is giant star with a classification of K0 III.[4]
The variability of this system was first noticed in 1965 by W. Strohmeier of Remeis-Observatory in Bamberg, Germany.[9] He later discovered that the variability was caused by a binary companion eclipsing the primary star.[10]