Iota Capricorni

Iota Capricorni
Location of ι Capricorni (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Capricornus
Right ascension 21h 22m 14.79598s[1]
Declination −16° 50′ 04.3580″[1]
Apparent magnitude (V) +4.296[2]
Characteristics
Spectral type G8 III[3]
U−B color index +0.63[2]
B−V color index +0.89[2]
Variable type BY Dra[4]
Astrometry
Radial velocity (Rv)+12.31±0.13[5] km/s
Proper motion (μ) RA: 29.403±0.189 mas/yr[1]
Dec.: 4.909±0.123 mas/yr[1]
Parallax (π)16.2048 ± 0.1688 mas[1]
Distance201 ± 2 ly
(61.7 ± 0.6 pc)
Absolute magnitude (MV)+0.18[6]
Details[5]
Mass2.89±0.08 M☉
Radius10.67±0.62 R☉
Luminosity83 L☉
Surface gravity (log g)3.05±0.10 cgs
Temperature5,200±28 K
Metallicity [Fe/H]0.05±0.05 dex
Rotation68 d[7]
Rotational velocity (v sin i)4.37±0.45 km/s
Age390 Myr
Other designations
ι Cap, 32 Cap, BD−17°6245, FK5 1561, HD 203387, HIP 105515, HR 8167, SAO 164346[8]
Database references
SIMBADdata

Iota Capricorni (ι Cap, ι Capricorni) is a solitary,[9] yellow-hued star in the southern constellation of Capricornus. It can be seen with the naked eye, having an apparent visual magnitude of +4.3.[2] Based upon an annual parallax shift of 16.2 mas as seen from the Earth,[1] the star is located about 201 light years from the Sun. At that distance, the visual magnitude of the star is diminished by an extinction factor of 0.08 due to interstellar dust.[5]

A visual band light curve for iota Capricorni, adapted from Henry et al. (1995)[10]

This is an evolved G-type giant star with a stellar classification of G8 III.[3] It is classified as a BY Draconis type[4] variable star. This is a chromospherically-active star with a longitudinal magnetic field strength of 8.3±0.6 G and an X-ray luminosity of 4.482×1030 erg s−1.[7] The activity and photometric variation of the star allow an estimate of its rotation period as 68 days.[7]

Iota Capricorni has an estimated 2.9 times the mass of the Sun and nearly 11 times the Solar radius. It is 390 million years old and is radiating 83 times the solar luminosity from its chromosphere at an effective temperature of 5,200 K.[5]

  1. ^ a b c d e Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference aaass22_9 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference houk1988 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Kazarovets1997 was invoked but never defined (see the help page).
  5. ^ a b c d Cite error: The named reference jofre2015 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Radick1998 was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference auriere2015 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Henry was invoked but never defined (see the help page).