Gemini. A story of the love and loyalty of two brothers parted only by death. Includes a star that's actually a system of six stars, and a giant star that can help us measure distances in space. Contains an object that completely baffled astronomers for twenty years.

Gemini – the Celestial Twins

The Geminga pulsar is a very strange object. It's a spinning neutron star. Usually, pulsars are detected because they give out a beam of radio waves which pulse like the light of a lighthouse as it turns. But this one doesn't give out radio waves. It was first noted as a source of gamma rays (very high energy light waves), but it took twenty years to match this to any astronomical object. "Geminga" is short for "Gemini gamma ray source.” But showing that astronomers have a sense of humor, it also is very similar to a phrase in an Italian dialect which means "It's not here."

Castor isn't a single star. If you look through an amateur telescope you can see that there are two stars. Here's a nice picture by English astrophotographer Damian Peach: Castor. Each of these two stars has a companion that even big telescopes can't see. They use special equipment to detect them. But there are two more, because Castor is a sextuple - yes, SIX! - star system. The last two are a pair of red dwarfs which aren't visible in Damian's photo.

There is a building in Bucharest which is decorated with the signs of the zodiac on the outside. Here is Andrei Dorian Gheorghe's photograph of Gemini with his "astropoem": Gemini