Eta Scorpii Explained

Eta Scorpii, Latinized from η Scorpii, is a star in the southern zodiac constellation of Scorpius. With an apparent visual magnitude of 3.33, this is one of the brighter members of the Scorpius and is the furthest south of the constellation stars with a Bayer designation. The distance to this star can be estimated using parallax measurements, yielding a value of 73.5abbr=offNaNabbr=off with a 0.4% margin of error.

The stellar classification of this star has undergone some revision over time, with the star being classified anywhere from an F-type main sequence star to a giant star. In 2006, the NStars program assigned it a class of F5 IV, where the luminosity class of 'IV' indicates this is a subgiant star that is exhausting the supply of hydrogen at its core and is in the process of evolving into a giant star. It has around 1.6 times the Sun's mass with an estimated age of 1.1 billion years. The star is radiating about 18 times the luminosity of the Sun from its outer atmosphere at an effective temperature of 6,533 K. It is this heat that gives it a yellow-white hue that is typical for an F-type star.

Eta Scorpii is rotating rapidly, with a projected rotational velocity of . This is causing the star to spin on its axis with a period of less than a day. It is an X-ray emitter with its stellar corona giving off an X-ray luminosity of . In 1991 it was identified as a possible barium star, as it displays an enhanced abundance of the element barium in its spectrum. Overall, the abundance of elements other than hydrogen and helium, what astronomers term the star's metallicity, is similar to the abundance in the Sun.

References

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[8]

[9]

[10]

[11]

[12]

[13]

[14]

Notes and References

  1. Precision angular diameters for 16 southern stars with VLTI/PIONIER . Rains . Adam D. . Ireland . Michael J. . White . Timothy R. . Casagrande . Luca . Karovicova . I. . Monthly Notices of the Royal Astronomical Society . 493 . 2 . 2377–2394 . April 2020 . 2004.02343 . 2020MNRAS.493.2377R . 10.1093/mnras/staa282 . free .
  2. F. . van Leeuwen . November 2007 . Validation of the new Hipparcos reduction . Astronomy and Astrophysics . 474 . 2 . 653–664 . 2007A&A...474..653V . 10.1051/0004-6361:20078357 . 0708.1752 . 18759600 .
  3. Evans . D. S. . June 20–24, 1966 . Batten . Alan Henry . Heard . John Frederick . The Revision of the General Catalogue of Radial Velocities . Determination of Radial Velocities and their Applications . Proceedings from IAU Symposium . 30 . 57 . University of Toronto . . 1967IAUS...30...57E .
  4. Pizzolato . N. . Maggio . A. . Sciortino . S. . Evolution of X-ray activity of 1-3 Msun late-type stars in early post-main-sequence phases . Astronomy and Astrophysics . 361 . 614–628 . September 2000 . 2000A&A...361..614P .
  5. Gray . R. O. . Corbally . C. J. . Garrison . R. F. . McFadden . M. T. . Bubar . E. J. . McGahee . C. E. . O'Donoghue . A. A. . Knox . E. R. . Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc-The Southern Sample . The Astronomical Journal . 132 . 1 . 161–170 . July 2006 . 10.1086/504637 . 2006AJ....132..161G . astro-ph/0603770 . 119476992 .
  6. Bok . B. J. . Bok . P. F. . Miller . E. W. . Photometric standards for the southern hemisphere. II . Astronomical Journal . 77 . 733 . November 1972 . 10.1086/111346 . 1972AJ.....77..733B . free .
  7. Vines . Jose I. . Jenkins . James S. . June 2022 . ARIADNE: measuring accurate and precise stellar parameters through SED fitting . Monthly Notices of the Royal Astronomical Society . en . 513 . 2 . 2719–2731 . 10.1093/mnras/stac956 . free . 2204.03769 . 2022MNRAS.513.2719V . 0035-8711.
  8. Holmberg . J. . Nordstrom . B. . Andersen . J. . The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics . Astronomy and Astrophysics . 501 . 3 . July 2009 . 941–947 . 10.1051/0004-6361/200811191 . 2009A&A...501..941H. 0811.3982 . 118577511 .
  9. Mallik . Sushma V. . Parthasarathy . M. . Pati . A. K. . Lithium and rotation in F and G dwarfs and subgiants . Astronomy and Astrophysics . 409 . 251–261 . October 2003 . 1 . 10.1051/0004-6361:20031084 . 2003A&A...409..251M . free .
  10. Web site: LTT 6848 -- High proper-motion Star . SIMBAD . . 2012-02-10 .
  11. Lu . Phillip K. . Taxonomy of barium stars . Astronomical Journal . 101 . 2229–2254 . June 1991 . 10.1086/115845 . 1991AJ....101.2229L . free .
  12. Web site: The Colour of Stars . December 21, 2004 . Australia Telescope, Outreach and Education . . 2012-02-10 .
  13. Book: Robert . Burnham . Burnham's celestial handbook: an observer's guide to the universe beyond the solar system . 3 . Dover books explaining science . 2nd . . 1978 . 0-486-23673-0 . 1675 .
  14. Web site: James B. . Kaler . Eta Scorpii . Stars . . 2012-02-10 .

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Eta Scorpii".

Except where otherwise indicated, Everything.Explained.Today is © Copyright 2009-2026, A B Cryer, All Rights Reserved. Cookie policy.