Epsilon Delphini
Epsilon Delphini (ε Delphini, abbreviated Eps Del, ε Del), officially named Aldulfin /ælˈdʌlfən/, is a solitary, blue-white hued star in the northern constellation of Delphinus. It is visible to the naked eye with an apparent visual magnitude of 4.03. Based upon an annual parallax shift of 9.87 mas as seen from the Earth, the system is located about 330 light-years from the Sun. At Epsilon Delphini's distance, the visual magnitude is diminished by an extinction factor of 0.11 due to interstellar dust. The star is moving closer to the Sun with a radial velocity of −19 km/s.
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Delphinus |
| Right ascension | 20h 33m 12.77192s |
| Declination | +11° 18′ 11.7412″ |
| Apparent magnitude (V) | 4.03 (3.95−4.05) |
| Characteristics | |
| Spectral type | B6 III |
| U−B color index | −0.46 |
| B−V color index | −0.13 |
| Variable type | suspected |
| Astrometry | |
| Radial velocity (Rv) | −19.4±0.7 km/s |
| Proper motion (μ) | RA: +11.96 mas/yr Dec.: −28.97 mas/yr |
| Parallax (π) | 9.87 ± 0.21 mas |
| Distance | 330 ± 7 ly (101 ± 2 pc) |
| Absolute magnitude (MV) | −0.06 |
| Details | |
| Radius | 4.6 R☉ |
| Luminosity | 676 L☉ |
| Surface gravity (log g) | 3.71±0.09 cgs |
| Temperature | 13,614±15 K |
| Metallicity [Fe/H] | +0.08±0.10 dex |
| Rotational velocity (v sin i) | 52±4 km/s |
| Age | 220 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is a B-type giant star with a stellar classification of B6 III. It has 4.6 times the Sun's radius and is radiating 676 times the solar luminosity from its photosphere at an effective temperature of 13,614 K. The star may be slightly variable, occasionally brightening to magnitude 3.95. It is spinning with a projected rotational velocity of 52 km/s.