Iota Lyrae

Iota Lyrae

A light curve for Iota Lyrae, plotted from TESS data[1]
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Lyra
Right ascension 19h 07m 18.13251s[2]
Declination +36° 06′ 00.5592″[2]
Apparent magnitude (V) 5.22[3]
Characteristics
Spectral type B6IV[4]
Variable type Be star[5]
Astrometry
Radial velocity (Rv)−26.0±4.6[6] km/s
Proper motion (μ) RA: −1.437[2] mas/yr
Dec.: −3.876[2] mas/yr
Parallax (π)3.5858 ± 0.1924 mas[2]
Distance910 ± 50 ly
(280 ± 10 pc)
Absolute magnitude (MV)−1.94[7]
Orbit[8]
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
Mass5.2[9] M☉
Radius6.7[10] R☉
Luminosity854[10] L☉
Surface gravity (log g)3.54[9] cgs
Temperature12,059[10] K
Metallicity [Fe/H]−0.11[9] dex
Rotational velocity (v sin i)224[11] km/s
Age168[12] 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[13]
Database references
SIMBADdata

ι Lyrae, Latinised as Iota Lyrae, is a binary star[3] 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.[3] 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.[6]

This is a wide binary system with a computed orbital period of 217 years and an eccentricity of 0.6.[8] The primary component has a stellar classification of B6IV,[4] matching a B-type subgiant star. It is a Be star,[14] displaying emission lines in its spectrum, and is spinning rapidly with a projected rotational velocity of 224 km/s.[11] The star ranges in brightness from magnitude 5.20 down to 5.27.[5] 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.

  1. ^ Cite error: The named reference MAST was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Lesh1968 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Samus2017 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference ORB6 was invoked but never defined (see the help page).
  9. ^ a b c Cite error: The named reference starhorse was invoked but never defined (see the help page).
  10. ^ a b c Cite error: The named reference mcdonald2017 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference zorec2012 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference gontcharov2012 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Abt1984 was invoked but never defined (see the help page).