Iota Trianguli Australis

Iota Trianguli Australis

A light curve for Iota Trianguli Australis, plotted from Hipparcos data[1]
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Triangulum Australe
Right ascension 16h 27m 57.34498s[2]
Declination −64° 03′ 28.5964″[2]
Apparent magnitude (V) +5.27[3]
Characteristics
Spectral type F4 IV[4]
U−B color index −0.02[3]
B−V color index +0.36[3]
Variable type γ Dor[5]
Astrometry
Radial velocity (Rv)−5.6±4.2[6] km/s
Proper motion (μ) RA: +53.12[2] mas/yr
Dec.: +25.45[2] mas/yr
Parallax (π)25.77 ± 0.51 mas[2]
Distance127 ± 3 ly
(38.8 ± 0.8 pc)
Absolute magnitude (MV)+2.34[7]
Orbit[5]
Period (P)39.880±0.002 d
Eccentricity (e)0.253±0.004
Periastron epoch (T)54661.65 ± 0.11 HJD
Argument of periastron (ω)
(secondary)		93.1±1.1°
Semi-amplitude (K1)
(primary)		38.4±0.3 km/s
Semi-amplitude (K2)
(secondary)		43.9±0.3 km/s
Details
ι TrA A
Mass1.42[8] M☉
Surface gravity (log g)4.28±0.14[8] cgs
Temperature7,045±240[8] K
Metallicity [Fe/H]−0.16[9] dex
Rotational velocity (v sin i)13.0±0.9[7] km/s
Age735[8] Myr
ι TrA B
Rotational velocity (v sin i)10.0±1.7[7] km/s
Other designations
ι TrA, CPD−63° 3923, GC 22100, HD 147787, HIP 80645, HR 6109, SAO 253555, CCDM 16280-6403, WDS J16280-6403A[10]
Database references
SIMBADdata

Iota Trianguli Australis (ι Trianguli Australis) is a binary star[11] system in the constellation Triangulum Australe. It is visible to the naked eye with a combined apparent visual magnitude of +5.27.[3] Based upon an annual parallax shift of 25.77 mas as seen from the Earth, it is located around 127 light years from the Sun. The system appears to be moving closer to the Sun with a radial velocity of around −6 km/s.[6]

Iota Trianguli Australis is a double-lined spectroscopic binary system with an orbital period of 39.88 days and an eccentricity of 0.25. The brighter member, component A, is yellow-white hued F-type subgiant star and a Gamma Doradus type variable, pulsating by 0.12 magnitudes with a dominant period of 1.45 days.[5]

There a magnitude 9.42 visual companion, located 16.2 arcseconds away.[12] The pair show as a yellow and a white star when seen though a 7.5 cm telescope.[13]

  1. ^ Cite error: The named reference HIPCurve was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference Nicolet1978 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Malaroda1975 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference DeCat2009 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference AmmlerVonEiff2012 was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference David2015 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Casagrande2011 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Mason2014 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Hartung1984 was invoked but never defined (see the help page).