"me" wrote in
. uk:

Hi

Sirius B, a white dwarf, has a surface temperature of around 25,000
degrees C. Sirius A, a blue/white main sequence star has a surface
temperature of around 12,000 degrees C. Usually the bluer a star is,
the hotter it is. Just wondered why it's not the case here.




The term white dwarf is just a name to distinguish from red dwarf. The
spectra of Sirius B versus A is just as expected by the surface
temperature difference. Note that white dwarf's are slowly cooling down
as they have no internal source of energy production.

K.