Iota Apodis

ι Apodis
Location of ι Apodis (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Apus
Right ascension 17h 22m 05.87559s[1]
Declination –70° 07′ 23.5400″[1]
Apparent magnitude (V) 5.41[2] (5.90/6.46)[3]
Characteristics
Spectral type B9 V + B9.5 V[3]
U−B color index −0.23[2]
B−V color index −0.04[2]
Astrometry
Radial velocity (Rv)−4.3[4] km/s
Proper motion (μ) RA: −1.844 ± 0.266[5] mas/yr
Dec.: −10.811 ± 0.303[5] mas/yr
Parallax (π)3.1403 ± 0.1782 mas[5]
Distance1,040 ± 60 ly
(320 ± 20 pc)
Orbit[6]
Period (P)59.32±3.0 yr
Semi-major axis (a)0.115±0.005″
Eccentricity (e)0.172±0.050
Inclination (i)69.4±3.0°
Longitude of the node (Ω)119.6±4.0°
Argument of periastron (ω)
(secondary)		270.5±7.0°
Details
ι Aps A
Mass3.89±1.02[6] M☉
ι Aps B
Mass3.45±0.90[6] M☉
Other designations
CPD−69 2719, FK5 642, HD 156190, HIP 84979, HR 6411, SAO 257491, WDS J17221−7007[7]
Database references
SIMBADdata

Iota Apodis (ι Aps, ι Apodis) is the Bayer designation for a binary star[3] system in the southern circumpolar constellation of Apus. It is a faint target at an apparent visual magnitude of 5.41,[2] but still visible to the naked eye from suitably dark skies. The distance to this star can be roughly gauged from parallax measurements, yielding an estimate of 1,300 light-years (400 parsecs) with a 20% margin of error.[1]

Both stars are B-type main sequence stars, which indicates they shine with a blue-white hue.[8] The brighter component has a stellar classification of B9 V and an apparent magnitude 5.90, while the second member is a B9.5 V star with a magnitude of 6.46. The pair have an angular separation of 0.091 arcseconds[3] with an estimated orbital period of 59.32 years. They are about 3.89 and 3.45 times as massive as the Sun.[6]

  1. ^ a b c Cite error: The named reference aaa474_2_653 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference aass34_1 was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference mnras389_2_869 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference gcsrv was invoked but never defined (see the help page).
  5. ^ a b c Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051.
  6. ^ a b c d Cite error: The named reference Docobo2013 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference csiro was invoked but never defined (see the help page).