AH Scorpii explained

AH Scorpii (abbreviated to AH Sco) is a red supergiant variable star located in the constellation Scorpius. It is one of the largest stars known by radius and is also one of the most luminous red supergiant stars in the Milky Way.

Distance

The distance of AH Scorpii is considered to be uncertain. VLBI measurements of the masers have provided an accurate distance of based on observation of SiO, H2O, and OH masers in its oxygen-rich circumstellar material. The masers were observed to be approaching the star at 13 km/s, indicating overall contraction at around phase 0.55 of the visual variations.[1]

Characteristics

AH Scorpii is a dust-enshrouded red supergiant[2] and is classified as a semiregular variable star with a main period of 714 days. The total visual magnitude range is 6.5 - 9.6. No long secondary periods have been detected.[3] Modelling of AH Scorpii near maximum light has determined an effective temperature of and a luminosity of . A radius of was determined from an angular diameter of and the given distance of . Its angular diameter was re-measured at in 2023.[4]

See also

Notes and References

  1. 2008ApJ...681.1574C. 0803.1690. VLBI Observations of SiO Masers around AH Scorpii. The Astrophysical Journal. 681. 2. 1574–1583. Chen. Xi. Shen. Zhi-Qiang. 2008. 10.1086/588186. 7603031.
  2. 2005A&A...438..273V. astro-ph/0504379. An empirical formula for the mass-loss rates of dust-enshrouded red supergiants and oxygen-rich Asymptotic Giant Branch stars. Astronomy and Astrophysics. 438. 273–289. Van Loon. J. Th.. Cioni. M.-R. L.. Zijlstra. A. A.. Loup. C.. 2005. 1. 10.1051/0004-6361:20042555. 16724272.
  3. 2009JRASC.103...11P. Long Secondary Periods in Pulsating Red Supergiant Stars. Journal of the Royal Astronomical Society of Canada. 103. 11. Percy. John R.. Sato. Hiromitsu. 2009. 1.
  4. González-Torà . G. . Wittkowski . M. . Davies . B. . Plez . B. . December 19, 2023 . The effect of winds on atmospheric layers of red supergiants II. Modelling VLTI/GRAVITY and MATISSE observations of AH Sco, KW Sgr, V602 Car, CK Car and V460 Car . Astronomy & Astrophysics . 683 . A19 . 10.1051/0004-6361/202348047 . 0004-6361. 2312.12521 .