Iota Lyrae
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Lyra |
| Right ascension | 19h 07m 18.13251s |
| Declination | +36° 06′ 00.5592″ |
| Apparent magnitude (V) | 5.22 |
| Characteristics | |
| Spectral type | B6IV |
| Variable type | Be star |
| Astrometry | |
| Radial velocity (Rv) | −26.0±4.6 km/s |
| Proper motion (μ) | RA: −1.437 mas/yr Dec.: −3.876 mas/yr |
| Parallax (π) | 3.5858±0.1924 mas |
| Distance | 910 ± 50 ly (280 ± 10 pc) |
| Absolute magnitude (MV) | −1.94 |
| Orbit | |
| Period (P) | 216.93 yr |
| Semi-major axis (a) | 0.172″ |
| Eccentricity (e) | 0.637 |
| Inclination (i) | 145.5° |
| Longitude of the node (Ω) | 171.4° |
| Periastron epoch (T) | B 1997.28 |
| Argument of periastron (ω) (secondary) | 201.2° |
| Details | |
| Mass | 5.2 M☉ |
| Radius | 6.7 R☉ |
| Luminosity | 854 L☉ |
| Surface gravity (log g) | 3.54 cgs |
| Temperature | 12,059 K |
| Metallicity [Fe/H] | −0.11 dex |
| Rotational velocity (v sin i) | 224 km/s |
| Age | 168 Myr |
| Other designations | |
| ι Lyr, 18 Lyr, BD+35°3485, GC 26338, HD 178475, HIP 93903, HR 7262, SAO 67834, WDS 19073+3606, GSC 02652-01709 | |
| Database references | |
| SIMBAD | data |
ι Lyrae, Latinised as Iota Lyrae, is a binary star in the northern constellation of Lyra. It is visible to the naked eye as a dim, blue-white hued star with an apparent visual magnitude that fluctuates around 5.22. This object is located approximately 910 light years distant from the Sun based on parallax, but is drifting nearer with a radial velocity of −26 km/s.
This is a wide binary system with a computed orbital period of 217 years and an eccentricity of 0.6. The primary component has a stellar classification of B6IV, matching a B-type subgiant star. It is a Be star, displaying emission lines in its spectrum, and is spinning rapidly with a projected rotational velocity of 224 km/s. The star ranges in brightness from magnitude 5.20 down to 5.27. It has about five times the mass of the Sun and is radiating 854 times the Sun's luminosity from its photosphere at an effective temperature of 12,059 K.