74 Aquarii
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 22h 53m 28.70492s |
| Declination | −11° 36′ 59.4532″ |
| Apparent magnitude (V) | 5.8 |
| Characteristics | |
| Spectral type | B8IV/V (B9pHgMn)) |
| U−B color index | −0.245 |
| B−V color index | −0.082 |
| Variable type | a2 CVn |
| Astrometry | |
| Proper motion (μ) | RA: +21.539 mas/yr Dec.: +2.282 mas/yr |
| Parallax (π) | 5.5008±0.6556 mas |
| Distance | approx. 590 ly (approx. 180 pc) |
| Absolute magnitude (MV) | −1.19 |
| Orbit | |
| Primary | 74 Aquarii A |
| Companion | 74 Aquarii B |
| Period (P) | 9.479±0.044 yr |
| Semi-major axis (a) | 0.0460±0.0061″ |
| Eccentricity (e) | 0.862±0.029 |
| Inclination (i) | 29.8±17.4° |
| Longitude of the node (Ω) | 40.9±20.3° |
| Periastron epoch (T) | 2010.039±0.134 |
| Argument of periastron (ω) (secondary) | 70.7±16.1° |
| Orbit | |
| Primary | 74 Aquarii Aa |
| Companion | 74 Aquarii Ab |
| Period (P) | 3.429616±0.000004 d |
| Eccentricity (e) | 0.05±0.02 |
| Periastron epoch (T) | 2452909.150±0.007 JD |
| Argument of periastron (ω) (secondary) | 86.5±0.8° |
| Semi-amplitude (K1) (primary) | 95±2 km/s |
| Semi-amplitude (K2) (secondary) | 113±2 km/s |
| Details | |
| Aa | |
| Mass | 2.72 M☉ |
| Rotational velocity (v sin i) | 20 km/s |
| Ab | |
| Mass | 2.53 M☉ |
| B | |
| Mass | 3.11 M☉ |
| Other designations | |
| HI Aqr, BD−12 6371, HD 216494, HIP 113031, HR 8704, SAO 165359 | |
| Database references | |
| SIMBAD | data |
74 Aquarii (abbreviated 74 Aqr) is a triple star system in the constellation of Aquarius. 74 Aquarii is its Flamsteed designation and it also bears the variable star designation HI Aquarii. The combined apparent visual magnitude is 5.8, although it is very slightly variable, and it is located at a distance of 590 light-years (180 parsecs) from Earth.
Jean Manfroid and Gautier Mathys reported that 74 Aquarii is a variable star in 1985. Based on that result it was given its variable star designation in 1987.