Iota Octantis

ι Octantis
Observation data; Epoch J2000.0 Equinox J2000.0 (ICRS)
Constellation	Octans
	A
Right ascension	12h 54m 58.80097s
Declination	−85° 07′ 24.1092″
Apparent magnitude (V)	5.83
	B
Right ascension	12h 54m 58.33659s
Declination	−85° 07′ 24.4647″
Apparent magnitude (V)	6.75
Characteristics
Spectral type	K0III + K0
U−B color index	+0.79
B−V color index	+1.02
Astrometry
Radial velocity (Rv)	53.4±0.7 km/s
Proper motion (μ)	RA: +67.20 mas/yr ; Dec.: +24.76 mas/yr
Parallax (π)	9.27±0.46 mas
Distance	350 ± 20 ly ; (108 ± 5 pc)
Absolute magnitude (MV)	+0.29
Details
Mass	2.49+1.48; −1.31 M☉
Luminosity	81±9 L☉
Temperature	4,890±110 K
Metallicity [Fe/H]	−0.3 dex
Rotational velocity (v sin i)	1.9±1.3 km/s
Age	725 Myr
Other designations
	ι Octantis, 16 G. Octantis, CPD−84°407, GC 17460, HD 111482, HIP 63031, HR 4870, SAO 258654, WDS J12550-8507AB
Database references
SIMBAD	data

Iota Octantis, Latinized from ι Octantis, is a double star^[10] in the southern circumpolar constellation Octans. The two components are separated by less than an arc-second, so cannot be resolved without a telescope, but their combined apparent magnitude of 5.45^[6] makes Iota Octantis faintly visible to the naked eye in dark skies. The system is located at a distance of 350 light years^[5] based on its annual parallax shift, and is drifting away at a rate of 53.4 km/s.^[4]

Iota Octantis A has a classification of K0 III, which indicates that it is an evolved K-type star that exhausted hydrogen at its core and left the main sequence. Iota Octantis B also has a spectral type of K0. At present Iota Octantis A has 2.49 times the mass of the Sun^[7] and radiates at 81 times the luminosity of the Sun^[7] from its enlarged photosphere at an effective temperature of 4,890 K,^[7] which gives it an orangish-yellow hue. Iota Octantis is metal deficient^[7] and spins slowly with a projected rotational velocity of 1.9 km/s.^[8]

Eggleton et al. states that both stars have similar spectral types,^[10] but there is a faint tenth magnitude companion with a classification of F8 located 60.1″ away,^[11] which is unrelated to the two.

References

^ ^a ^b ^c ^d ^e ^f Fabricius, C.; Høg, E.; Makarov, V. V.; Mason, B. D.; Wycoff, G. L.; Urban, S. E. (2002). "The Tycho double star catalogue". Astronomy and Astrophysics. 384: 180. Bibcode:2002A&A...384..180F. doi:10.1051/0004-6361:20011822.
^ Kharchenko, N. V. (2001). "All-sky compiled catalogue of 2.5 million stars". Kinematika I Fizika Nebesnykh Tel. 17 (5): 409. Bibcode:2001KFNT...17..409K.
^ ^a ^b Johnson, H. L.; Mitchell, R. I.; Iriarte, B.; Wisniewski, W. Z. (January 1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory. 4: 99–110. Bibcode:1966CoLPL...4...99J.
^ ^a ^b Kharchenko, N.V.; Scholz, R.-D.; Piskunov, A.E.; Röser, S.; Schilbach, E. (November 2007). "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ~55000 stars and mean radial velocities of 516 Galactic open clusters and associations". Astronomische Nachrichten. 328 (9): 889–896. arXiv:0705.0878. Bibcode:2007AN....328..889K. doi:10.1002/asna.200710776. ISSN 0004-6337.
^ ^a ^b ^c ^d van Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". Astronomy & Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. ISSN 0004-6361.
^ ^a ^b Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015.
^ ^a ^b ^c ^d ^e Charbonnel, C.; Lagarde, N.; Jasniewicz, G.; North, P. L.; Shetrone, M.; Krugler Hollek, J.; Smith, V. V.; Smiljanic, R.; Palacios, A.; Ottoni, G. (January 2020). "Lithium in red giant stars: Constraining non-standard mixing with large surveys in the Gaia era". Astronomy & Astrophysics. 633: A34. arXiv:1910.12732. Bibcode:2020A&A...633A..34C. doi:10.1051/0004-6361/201936360. ISSN 0004-6361.
^ ^a ^b De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (January 2014). "A catalog of rotational and radial velocities for evolved stars: V. Southern stars⋆⋆⋆". Astronomy & Astrophysics. 561: A126. arXiv:1312.3474. Bibcode:2014A&A...561A.126D. doi:10.1051/0004-6361/201220762. ISSN 0004-6361.
^ "Digital Demo Room - Stellar Structure and Evolution Simulator". rainman.astro.illinois.edu. Retrieved 4 January 2022.
^ ^a ^b Eggleton, P. P.; Tokovinin, A. A. (11 September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. ISSN 0035-8711.
^ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (1 December 2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. ISSN 0004-6256.

[tychodouble-1] ^ ^a ^b ^c ^d ^e ^f Fabricius, C.; Høg, E.; Makarov, V. V.; Mason, B. D.; Wycoff, G. L.; Urban, S. E. (2002). "The Tycho double star catalogue". Astronomy and Astrophysics. 384: 180. Bibcode:2002A&A...384..180F. doi:10.1051/0004-6361:20011822.

[kharchenko2009-2] Kharchenko, N. V. (2001). "All-sky compiled catalogue of 2.5 million stars". Kinematika I Fizika Nebesnykh Tel. 17 (5): 409. Bibcode:2001KFNT...17..409K.

[Johnson1966-3] Johnson, H. L.; Mitchell, R. I.; Iriarte, B.; Wisniewski, W. Z. (January 1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory. 4: 99–110. Bibcode:1966CoLPL...4...99J.

[Kharchenko2007-4] Kharchenko, N.V.; Scholz, R.-D.; Piskunov, A.E.; Röser, S.; Schilbach, E. (November 2007). "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ~55000 stars and mean radial velocities of 516 Galactic open clusters and associations". Astronomische Nachrichten. 328 (9): 889–896. arXiv:0705.0878. Bibcode:2007AN....328..889K. doi:10.1002/asna.200710776. ISSN 0004-6337.

[VanLeeuwen2007-5] van Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". Astronomy & Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. ISSN 0004-6361.

[xhip-6] Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015.

[Charbonnel2020-7] Charbonnel, C.; Lagarde, N.; Jasniewicz, G.; North, P. L.; Shetrone, M.; Krugler Hollek, J.; Smith, V. V.; Smiljanic, R.; Palacios, A.; Ottoni, G. (January 2020). "Lithium in red giant stars: Constraining non-standard mixing with large surveys in the Gaia era". Astronomy & Astrophysics. 633: A34. arXiv:1910.12732. Bibcode:2020A&A...633A..34C. doi:10.1051/0004-6361/201936360. ISSN 0004-6361.

[DeMederios2014-8] De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (January 2014). "A catalog of rotational and radial velocities for evolved stars: V. Southern stars⋆⋆⋆". Astronomy & Astrophysics. 561: A126. arXiv:1312.3474. Bibcode:2014A&A...561A.126D. doi:10.1051/0004-6361/201220762. ISSN 0004-6361.

[DDR2022-9] "Digital Demo Room - Stellar Structure and Evolution Simulator". rainman.astro.illinois.edu. Retrieved 4 January 2022.

[Eggleton2008-10] Eggleton, P. P.; Tokovinin, A. A. (11 September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. ISSN 0035-8711.

[Manson2001-11] Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (1 December 2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. ISSN 0004-6256.

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[8]

[9]

[10]

[11]

Observation data Epoch J2000.0 Equinox J2000.0 (ICRS)
Constellation	Octans
A
Right ascension	12^h 54^m 58.80097^s^[1]
Declination	−85° 07′ 24.1092″^[1]
Apparent magnitude (V)	5.83^[1]
B
Right ascension	12^h 54^m 58.33659^s^[1]
Declination	−85° 07′ 24.4647″^[1]
Apparent magnitude (V)	6.75^[1]
Characteristics
Spectral type	K0III + K0^[2]
U−B color index	+0.79^[3]
B−V color index	+1.02^[3]
Astrometry

Radial velocity (R_v)	53.4±0.7^[4] km/s
Proper motion (μ)	RA: +67.20^[5] mas/yr Dec.: +24.76^[5] mas/yr
Parallax (π)	9.27±0.46 mas^[5]
Distance	350 ± 20 ly (108 ± 5 pc)
Absolute magnitude (M_V)	+0.29^[6]

Details^[7]

Mass	2.49+1.48 −1.31 `M`_☉
Luminosity	81±9 `L`_☉
Temperature	4,890±110 K
Metallicity [Fe/H]	−0.3 dex
Rotational velocity (v sin i)	1.9±1.3^[8] km/s
Age	725^[9] Myr

Other designations
ι Octantis, 16 G. Octantis, CPD−84°407, GC 17460, HD 111482, HIP 63031, HR 4870, SAO 258654, WDS J12550-8507AB
Database references
SIMBAD	data

Iota Octantis

Hub talks

Iota Octantis

Iota Octantis

Hub rules

Iota Octantis

Hub overview

Add your contribution

Inside this hub

Media Collections

Timelines

Articles

Notes collections

Notes

Days in Chronicle

Root Wikipedia Article

Iota Octantis

References

Add your contribution

Related Hubs