Iota Andromedae
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Andromeda |
| Right ascension | 23h 38m 08.200s |
| Declination | +43° 16′ 05.06″ |
| Apparent magnitude (V) | +4.29 |
| Characteristics | |
| Evolutionary stage | main sequence |
| Spectral type | B8 V |
| U−B color index | –0.29 |
| B−V color index | –0.11 |
| Variable type | constant |
| Astrometry | |
| Radial velocity (Rv) | –0.5 km/s |
| Proper motion (μ) | RA: +27.163 mas/yr Dec.: −1.246 mas/yr |
| Parallax (π) | 6.4313±0.1375 mas |
| Distance | 510 ± 10 ly (155 ± 3 pc) |
| Absolute magnitude (MV) | −1.63 |
| Details | |
| Mass | 3.1 M☉ 3.98±0.06 M☉ |
| Radius | 4.6 R☉ |
| Luminosity | 638 L☉ |
| Surface gravity (log g) | 3.35 cgs |
| Temperature | 12,620 K |
| Metallicity [Fe/H] | −0.19±0.14 dex |
| Rotational velocity (v sin i) | 70 km/s |
| Age | 116 Myr |
| Other designations | |
| Rasalnaqa, ι And, 17 And, BD+42°4720, FK5 891, HD 222173, HIP 116631, HR 8965, SAO 53216, PPM 64473 | |
| Database references | |
| SIMBAD | data |
Iota Andromedae, also named Rasalnaqa, is a single star in the northern constellation of Andromeda. It has the Flamsteed designation 17 Andromedae, while Iota Andromedae is the Bayer designation as Latinized from ι Andromedae. This object is visible to the naked eye at night as a faint, blue-white hued star with an apparent visual magnitude of +4.29. Based upon parallax measurements, it is located approximately 510 light years distant from the Sun.
This object is a B-type main-sequence star with a stellar classification of B8 V. It is among the least variable stars observed during the Hipparcos mission. The star is 116 million years old with 3.1 times the mass of the Sun and is spinning with a projected rotational velocity of 70 km/s. It is radiating 638 times the luminosity of the Sun from its photosphere at an effective temperature of 12,620 K. The star is somewhat metal-poor, although the abundance of helium is close to solar. The latter excludes it from membership among the class of peculiar stars. Iota Andromedae is a debris disk candidate, showing an infrared excess at a wavelength of 18 μm.