HAZMAT. V. The Ultraviolet and X-Ray Evolution of K Stars

Tyler Richey-Yowell, Evgenya Shkolnik, Adam C. Schneider, Ella Osby, Travis Barman, Victoria S. Meadows

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Knowing the high-energy radiation environment of a star over a planet's formation and evolutionary period is critical in determining if that planet is potentially habitable and if any biosignatures could be detected, as UV radiation can severely change or destroy a planet's atmosphere. Current efforts for finding a potentially habitable planet are focused on M stars, yet K stars may offer more habitable conditions due to decreased stellar activity and more distant and wider habitable zones (HZs). While M star activity evolution has been observed photometrically and spectroscopically, there has been no dedicated investigation of K star UV evolution. We present the first comprehensive study of the near-UV, far-UV, and X-ray evolution of K stars. We used members of young moving groups and clusters ranging in age from 10 to 625 Myr combined with field stars and their archived GALEX UV and ROSAT X-ray data to determine how the UV and X-ray radiation evolve. We find that the UV and X-ray flux incident on an HZ planet is 5-50 times lower than that of HZ planets around early-M stars and 50-1000 times lower than those around late-M stars, due to both an intrinsic decrease in K dwarf stellar activity occurring earlier than for M dwarfs and the more distant location of the K dwarf HZ.

Original languageEnglish (US)
Article numberA17
JournalAstrophysical Journal
Volume872
Issue number1
DOIs
StatePublished - Feb 10 2019

Fingerprint

K stars
planets
M stars
planet
stellar activity
x rays
radiation
late stars
early stars
star distribution
atmospheres
stars
atmosphere
energy

Keywords

  • stars: evolution
  • stars: low-mass

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Richey-Yowell, T., Shkolnik, E., Schneider, A. C., Osby, E., Barman, T., & Meadows, V. S. (2019). HAZMAT. V. The Ultraviolet and X-Ray Evolution of K Stars. Astrophysical Journal, 872(1), [A17]. https://doi.org/10.3847/1538-4357/aafa74

HAZMAT. V. The Ultraviolet and X-Ray Evolution of K Stars. / Richey-Yowell, Tyler; Shkolnik, Evgenya; Schneider, Adam C.; Osby, Ella; Barman, Travis; Meadows, Victoria S.

In: Astrophysical Journal, Vol. 872, No. 1, A17, 10.02.2019.

Research output: Contribution to journalArticle

Richey-Yowell, T, Shkolnik, E, Schneider, AC, Osby, E, Barman, T & Meadows, VS 2019, 'HAZMAT. V. The Ultraviolet and X-Ray Evolution of K Stars', Astrophysical Journal, vol. 872, no. 1, A17. https://doi.org/10.3847/1538-4357/aafa74
Richey-Yowell T, Shkolnik E, Schneider AC, Osby E, Barman T, Meadows VS. HAZMAT. V. The Ultraviolet and X-Ray Evolution of K Stars. Astrophysical Journal. 2019 Feb 10;872(1). A17. https://doi.org/10.3847/1538-4357/aafa74
Richey-Yowell, Tyler ; Shkolnik, Evgenya ; Schneider, Adam C. ; Osby, Ella ; Barman, Travis ; Meadows, Victoria S. / HAZMAT. V. The Ultraviolet and X-Ray Evolution of K Stars. In: Astrophysical Journal. 2019 ; Vol. 872, No. 1.
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