Eta Persei
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Perseus |
| Right ascension | 02h 50m 41.810s |
| Declination | +55° 53′ 43.80″ |
| Apparent magnitude (V) | 3.79 |
| Characteristics | |
| Evolutionary stage | Red supergiant |
| Spectral type | K3 Ib |
| U−B color index | +1.90 |
| B−V color index | +1.69 |
| Astrometry | |
| Radial velocity (Rv) | −1.07±0.27 km/s |
| Proper motion (μ) | RA: +16.346 mas/yr Dec.: −13.518 mas/yr |
| Parallax (π) | 3.2657±0.1873 mas |
| Distance | 1,000 ± 60 ly (310 ± 20 pc) |
| Absolute magnitude (MV) | −4.29 |
| Details | |
| Mass | 8±0.4 M☉ |
| Radius | 173.1+9.69 −10.8 R☉ |
| Luminosity | 7,508±864 L☉ |
| Surface gravity (log g) | 0.26 cgs |
| Temperature | 4082±30 K |
| Rotational velocity (v sin i) | 5.8 km/s |
| Age | 37.8±6.2 Myr |
| Other designations | |
| Miram, η Persei, η Per, Eta Per, 15 Persei, BD+55 714, CCDM J02506+5553A, FK5 99, GC 3390, HD 17506, HIP 13268, HR 834, IDS 02434+5529 A, PPM 28039, SAO 23655, WDS J02507+5554A | |
| Database references | |
| SIMBAD | data |
Eta Persei (η Persei, abbreviated Eta Per, η Per), is a red supergiant in the constellation of Perseus. Parallax measurements by the Gaia spacecraft imply that it is 1,000 is light-years away from Earth. At such distance, interstellar dust diminishes its apparent brightness by 0.47 magnitudes.
The two components of Eta Persei itself are designated Eta Persei A (officially named Miram /ˈmaɪræm/, a recent name for the system) and B.