Iota Centauri

ι Centauri
Location of ι Centauri (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Centaurus
Right ascension 13h 20m 35.81737s[1]
Declination −36° 42′ 44.2447″[1]
Apparent magnitude (V) +2.73[2]
Characteristics
Spectral type A2 V (kA15hA3mA3va)[3]
U−B color index +0.01[2]
B−V color index +0.03[2]
Astrometry
Radial velocity (Rv)+0.1[4] km/s
Proper motion (μ) RA: −341.11[1] mas/yr
Dec.: −86.14[1] mas/yr
Parallax (π)55.49 ± 0.17 mas[1]
Distance58.8 ± 0.2 ly
(18.02 ± 0.06 pc)
Absolute magnitude (MV)+1.47[5]
Details
Mass2.03±0.03[6] M☉
Radius1.9 ± 0.05[6][a] R☉
Luminosity22.91+1.08
−1.03[6] L☉
Surface gravity (log g)4.11[7] cgs
Temperature9,160±70[6] K
Metallicity [Fe/H]–0.46[7] dex
Rotational velocity (v sin i)90.3[8] km/s
Age0.35[9] Gyr
Other designations
ι Cen, CD−36°8497, FK5 496, GJ 508.1, HD 115892, HIP 65109, HR 5028, SAO 204371[10]
Database references
SIMBADdata

Iota Centauri, Latinized from ι Centauri, is a star in the southern constellation of Centaurus. Based upon parallax measurements, it lies at a distance of approximately 58.6 light-years (18.0 parsecs) from Earth.[1] Iota Centauri has an apparent visual magnitude of +2.73,[2] making it easily visible to the naked eye.

In Chinese, 柱 (Zhǔ), meaning Pillars, refers to an asterism consisting of ι Centauri, υ2 Centauri, υ1 Centauri, a Centauri, ψ Centauri, 4 Centauri, 3 Centauri and 1 Centauri.[11] Consequently, the Chinese name for ι Centauri itself is 柱十一 (Zhǔ shíyī, English: the Eleventh Star of Pillars.)[12]

The spectrum of ι Centauri matches a stellar classification of A2 V. It is an A-type main sequence star that is generating energy by the nuclear fusion of hydrogen in its core region. This energy is being radiated from the outer envelope of the star at an effective temperature of 9,160 K,[6] giving the star a white hue.[13] It has about 2 times the Sun's mass, 1.9 times the Sun's radius,[6] and is roughly 350 million years old.[9] The abundance of elements other than hydrogen and helium, what astronomers term the metallicity, is only 35% of the abundance in the Sun.[7] A weak magnetic field has been tentatively identified with a strength of −77 ± 30 G.[14]

This star has an excess emission of infrared indicating it is surrounded by a circumstellar disk of dust, known as a debris disk. The disk is located within an orbital radius of six Astronomical Units from the star. The dust is unusually luminous for a star this age, suggesting that some process may have recently increased the amount of debris, such as collisions between planetesimals. Alternatively, the planetesimals in this system may have unusual physical properties. As of 2011, a search for planets in this system has thus far been unsuccessful.[9]

Iota Centauri appears to belong to the stellar kinematic group known as IC 2391. This is a group of around 16 co-moving stars that most likely originated in the same molecular cloud at least 45 million years ago.[15]

  1. ^ a b c d e f 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 clpl4_99 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference aj132_1_161 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference scfs was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  6. ^ a b c d e f Cite error: The named reference pearce was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference aaa490_1_297 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference aaa531_A143 was invoked but never defined (see the help page).
  9. ^ a b c Cite error: The named reference apjl736_2_L32 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. ^ (in Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.
  12. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 25 日
  13. ^ Cite error: The named reference csiro was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference aaa446_3_1089 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference aj140_3_713 was invoked but never defined (see the help page).


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