Tau Pegasi Explained

Tau Pegasi (τ Pegasi, abbreviated Tau Peg, τ Peg), formally named Salm,[1] is a magnitude 4.6 star 162 light years away in the constellation of Pegasus. With about twice the mass of the Sun and thirty times as luminous, it is a δ Scuti variable star with its brightness changing by a few hundredths of a magnitude over about an hour.

Nomenclature

τ Pegasi (Latinised to Tau Pegasi) is the star's Bayer designation.

The star bore the traditional names Salm,[2] Kerb (or El Khereb) and Markab (often spelled Markeb), a name shared with Alpha Pegasi, k Puppis and Kappa Velorum.[3] In 2016, the IAU organized a Working Group on Star Names (WGSN)[4] to catalog and standardize proper names for stars. The WGSN approved the name Salm (a homophone with the planet Samh) for this star and Markeb for the component Kappa Velorum A, both on 5 September 2017. Markab had previously been approved for Alpha Pegasi on 30 June 2016. All three are now so included in the List of IAU-approved Star Names.[1]

In Chinese, Chinese: 離宮 (Chinese: Lì Gōng), meaning Resting Palace, refers to an asterism consisting of Tau Pegasi, Lambda Pegasi, Mu Pegasi, Omicron Pegasi, Eta Pegasi and Nu Pegasi.[5] Consequently, the Chinese name for Tau Pegasi itself is Chinese: 離宮五 (Chinese: Lì Gōng wǔ), "the Fifth Star of Resting Palace".[6]

Properties

Tau Pegasi belongs to spectral class A5 Vp, making it an A-type main-sequence star. It is a type of chemically peculiar star with unusually weak spectral lines of iron peak elements, a class known as λ Boötis stars.

Tau Pegasi is a multiperiodic Delta Scuti variable, with reported pulsation periods ranging from 0.94 to 1.30 hours. It is rotating rapidly with a projected rotational velocity of 150 km/s. Tau Pegasi is radiating nearly 30 times the luminosity of the Sun from its outer atmosphere at an effective temperature of 7,762 K.

Notes and References

  1. Web site: Naming Stars . IAU.org . 16 December 2017.
  2. Book: Allen, Richard Hinckley . Star-names and their meanings . New York, Leipzig [etc.] G.E. Stechert . 1899 . 329 .
  3. 2004yCat.4027....0K. VizieR Online Data Catalog: HD-DM-GC-HR-HIP-Bayer-Flamsteed Cross Index (Kostjuk, 2002). VizieR On-line Data Catalog: IV/27A. Originally Published in: Institute of Astronomy of Russian Academy of Sciences (2002). 4027. Kostjuk. N. D.. 2004.
  4. Web site: IAU Working Group on Star Names (WGSN). 22 May 2016.
  5. 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, .
  6. 香港太空館 - 研究資源 - 亮星中英對照表, Hong Kong Space Museum. Accessed on line November 23, 2010.