Suppose you observe a previously unstudied star and find its apparent brightness. D. light curves all the times 13. D. white dwarfs 15. The method of spectroscopic parallax cannot be applied to stars beyond 100 pc. The most common kind of stars is low-luminosity stars.
Supergiants are about as common as the sun.
White dwarfs have such a low luminosity that even the nearest white dwarfs are not visible to the naked eye. To observe a visual binary, we must measure radial velocities. To observe a spectroscopic binary, we must be able to see both stars individually. The most massive main-sequence stars are the M stars. The neutrino process 35.