Alpha Indi Explained

Alpha Indi (α Ind, α Indi) is the brightest star in the southern constellation Indus. Parallax measurements imply that it is located about 100 light years from Earth. It is visible to the naked eye at an apparent visual magnitude of 3.22. Considering its distance and apparent magnitude, its absolute magnitude is equal to 0.65.

Characteristics

The stellar classification of Alpha Indi is K0 III-IV, meaning that it has exhausted the hydrogen at its core and evolved away from the main sequence, being now halfway between a subgiant and a giant star. It is 59 times more luminous than the Sun, has 88% more mass, and is estimated to be 1.6 billion years old. At this age, it has expanded to about 10 times the size of the Sun. The effective temperature of its photosphere is 4,900 K, giving it the characteristic orange hue of a K-type star. It may have two nearby M-type companion stars, which are located at least 2,000 AU from the primary.

Nomenclature

Alpha Indi is the star's Bayer designation. In China, this star is called Pe Sze where it also was known as the Persian, a title from the Jesuit missionaries.[1] The term Pe Sze is from the name of asterism Chinese: 波斯 (Chinese: Bō Sī, English: Persia). In Chinese astronomy, consequently, α Indi itself is known as Chinese: 波斯二 (Chinese: Bō Sī èr, English: the Second Star of Persia)[2]

Notes and References

  1. https://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Indus*.html Star Name - R.H.Allen p. 246
  2. AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 30 日)