Question

what type of star is in spectral class K and has a luminosity of 10^6

Answer 1

A star in spectral class K typically exhibits a surface temperature ranging from about 3,900 to 5,200 Kelvin and is characterized by its orange hue. Stars in this class are generally cooler than those in classes O, B, A, and F, and they are often classified as giants or subgiants.

If a star in this spectral class has a luminosity of \(10^6\) times that of the Sun (\(L_\odot\)), it would fall into the category of a K-type giant star. The higher luminosity indicates a significant size, typically suggesting that the star is in a later stage of its stellar evolution—likely having exhausted the hydrogen in its core and expanded in size.

Such a star would be much larger than the Sun and would have characteristics typical of a red or orange giant. An example of a K-type giant could include stars like Arcturus (Alpha Bootis), although it's not as luminous as \(10^6 L_\odot\). A star at this luminosity is unusual and would have undergone substantial evolutionary changes to reach such a state.