Astrophysics (Index)About

K-type star

(K, K-class star)
(spectral class of star a bit cooler than the Sun)

A K-type star is a star within the K-class, a spectral class indicating stars with neutral metal and very weak hydrogen absorption lines, with an orange color, and a surface temperature in the 3700-5200 K range. The spectral energy distribution (SED) peaks in the near-infrared/visible range. Main sequence stars of this class (sometimes termed orange dwarfs or K dwarfs) are on the order of 3/4 solar masses, 3/4 solar radius, and 1/5 solar luminosity. Such main sequence stars burn their hydrogen in tens of billions of years. Characteristics of K-type main sequence stars:

0.7-0.96radius(solar)
0.45-0.8mass(solar)
6-8absolute magnitude(visual)
0.08-0.6bolometric luminosity(solar)
18-70 billion yearsmain-sequence lifetime
12.1%abundance

K-type main sequence stars are a good bet for habitable extra-solar planets, but offer few planets for study because the stars are much rarer than M-type stars and much dimmer than the hotter classes. Giant stars can also be of a K-type, including supergiants and hypergiants. Example K-type stars include Arcturus (a red giant), Epsilon Eridani, Epsilon Indi, J1407 (a subgiant), and TW Hydrae (a pre-main-sequence star).


(star type,spectral class)
Further reading:
https://en.wikipedia.org/wiki/Stellar_classification#Class_K
https://en.wikipedia.org/wiki/K-type_main-sequence_star
http://www.solstation.com/stars3/100-ks.htm
https://lweb.cfa.harvard.edu/~pberlind/atlas/htmls/kstars.html
WaveLFreqPhoton
Energy
  
527nm569THz2.4eVbeginK-type star
725nm414THz1.8eVendK-type star

Referenced by pages:
55 Cancri e (55 Cnc e)
AB Pictoris (AB Pic)
barium star (Ba star)
calcium (Ca)
CHARA
FGK star
G band (G)
G-dwarf problem
HD 189733 b
hypergiant
Kepler Telescope
Kepler-16b
M dwarf
Morgan classification
post-starburst galaxy (PSB galaxy)
red dwarf
red giant
red-giant branch (RGB)
S-type star (S)
spectral class
Spectroscopic Properties of Cool Stars (SPOCS)
T4 Automated Photometric Telescope (T4 APT)
Transiting Exoplanet Survey Satellite (TESS)
Tucana Horologium association (THA)
TW Hydrae (TW Hya)
TW Hydrae association (TWA)
WASP-43b
WASP-67b
Wilson-Bappu effect

Index