Tuesday, February 8, 2011

Happy Birthday, Garrett!

Today is Garrett's 43rd birthday. That means he gets a new birthday star! The new star is 58 Eridani, in the Constellation Eridanus. 58 Eridani is 43.4 light years from Earth, meaning that the light we see today left the star about the time Garrett was born. 58 Eridani is a BY Draconis variable star (BY Draconis-type variables, which are emission-line dwarfs of dKe-dMe spectral type showing quasiperiodic light changes with periods from a fraction of a day to 120 days and amplitudes from several hundredths to 0.5 mag in V. The light variability is caused by axial rotation of a star with a variable degree of nonuniformity of the surface brightness (spots) and chromospheric activity. Some of these stars also show flares similar to those of UV Cet stars, and in those cases they also belong to the latter type and are simultaneously considered eruptive variables.) Oddly, I have no doubt Garrett knows what that means. Procyon, the eighth brightest star in the sky and one point of the Winter Hexagon, is a BY Draconis variable.

All I know is that it is not one of the brightest or one of the dimmest stars in Eridanus, the sixth largest constellation in the sky (Hydra, Virgo, Ursa Major, Cetus and Hercules are larger). But you'd probably have to be in a pretty dark place to see it well without a telescope.

Anyway, happy birthday, Garrett! And many, many more!