  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 22h 26m 34.2753s [1] |
| Declination | −16° 44′ 31.697″ [1] |
| Apparent magnitude (V) | 5.56 [2] (6.35/6.57) [3] |
| Characteristics | |
| Spectral type | G1 V + G5 V Fe–0.8 CH–1 [4] |
| U−B color index | +0.09 [2] |
| B−V color index | +0.61 [2] |
| Astrometry | |
| Radial velocity (Rv) | +2.1 [5] km/s |
| Proper motion (μ) | RA: +200.59 [1] mas/yr Dec.: +14.51 [1] mas/yr |
| Parallax (π) | 49.50±1.23 mas [1] |
| Distance | 66 ± 2 ly (20.2 ± 0.5 pc) |
| Absolute magnitude (MV) | 4.05 [5] (4.94/4.87) [3] |
| Orbit [6] | |
| Primary | 53 Aqr A |
| Companion | 53 Aqr B |
| Period (P) | 3500 yr |
| Semi-major axis (a) | 14.88″ |
| Eccentricity (e) | 0.90 |
| Inclination (i) | 44.13° |
| Longitude of the node (Ω) | 294.55° |
| Periastron epoch (T) | B 2023 |
| Argument of periastron (ω) (secondary) | 151.40° |
| Details | |
| 53 Aqr A | |
| Mass | 1.01 [7] M☉ |
| Radius | 1.11 [8] R☉ |
| Luminosity | 1.39 [8] L☉ |
| Surface gravity (log g) | 4.46 [3] cgs |
| Temperature | 5,922 [3] K |
| Metallicity [Fe/H] | −0.10 [3] dex |
| Rotational velocity (v sin i) | 8 [9] km/s |
| Age | 0.18–0.37 [10] Gyr |
| 53 Aqr B | |
| Mass | 0.99 [7] M☉ |
| Surface gravity (log g) | 4.44 [3] cgs |
| Temperature | 5,811 [3] K |
| Metallicity [Fe/H] | −0.19 [3] dex |
| Rotational velocity (v sin i) | 9 [9] km/s |
| Other designations | |
| GJ 859, HIP 110778. [11] | |
| 53 Aqr A: BD−17 6521, HD 212698, HR 8545, LTT 9026, SAO 165078. | |
| 53 Aqr B: BD−17 6520, HD 212697, HR 8544, LTT 9025, SAO 165077. | |
| Database references | |
| SIMBAD | 53 Aqr |
| 53 Aqr A | |
| 53 Aqr B | |
53 Aquarii (abbreviated 53 Aqr) is a binary star [12] system in the equatorial constellation of Aquarius. 53 Aquarii is its Flamsteed designation though the star also bears the Bayer designation of f Aquarii. The combined apparent visual magnitude of the pair is a 5.56, [2] making it just visible to the naked eye in dark suburban skies. Based upon an annual parallax shift of 49.50 milliarcseconds for the first component, this system is located at a distance of approximately 65 light-years (20 parsecs ) from Earth. [1]
This is a wide binary star system with a projected separation of 100 astronomical units; indicating that the two stars are at least this distance apart. [8] The primary component is a solar-type main sequence star with a stellar classification of G1 V. [4] It has about 99% of the Sun's mass, 111% of the Sun's radius, and shines with 139% of the luminosity of the Sun. [8] This energy is being emitted from an outer envelope at an effective temperature of 5,922 K, [3] giving it the golden hue of a G-type star. [13] An examination of the primary component with the Spitzer Space Telescope failed to detect any infrared excess that might otherwise be an indication of a circumstellar debris disk. [8]
The companion is a slightly cooler star with an effective temperature of 5,811 K. [3] It has a stellar classification of G5 V Fe–0.8 CH–1, [4] indicating it is a chemically peculiar G-type main sequence star showing an under-abundance of iron and the molecule CH in its spectrum. As of 2008, it has an angular separation of 1.325 arcseconds along a position angle of 30.9° from the primary. [14]
This system is coeval with the Castor Moving Group of stars that share a common motion through space; hence it is a candidate member of that association. This suggests that the system is young; its estimated age is in the range of 180 to 370 million years, based upon the spectrum and X-ray luminosity, respectively. [10]
