Luminosity

Henrietta Swan Leavitt discovered the relation between the luminosity and the period of Cepheid variable stars.

The planetarium show vividly illustrates how stars vary widely in mass, temperature, age, color, luminosity and size. But the underlying physics for each of the estimated 100 billion stars in our Milky Way galaxy — and in the 100 billion other galaxies — is the same.

They reported encountering a luminosity of great intensity and loving angelic beings.

We recognize the same pattern as in the left panel, with dM stars being much less frequent flarers than dMe stars of similar luminosity.

We derive rotation periods, photometric activity indices, flaring energies, mass loss rates, gyrochronological ages, X-ray luminosities and consider implications for the planetary magnetospheres and habitability.