Gamma Delphini and Struve 2725 -- Double Stars in Delphinus
The Lemon & Lime Star
The view of the twin double-stars Gamma Delphini and Struve 2725 together in the eyepiece
is a perfect example of why so many amateur astronomers seek out these pleasing objects.
There are only a few locations in the heavens where two-pairs of bright-stars can be viewed
together. There are also only a few double-stars that have such bright, colorful and contrasting
member stars that their color alone makes them a standout. Well the two doubles stars in this
drawing not only have these characteristics but also one of the stars is GREEN.
Why is a green star interesting? Well because, no star can truly shine with a green color. It
just is not physically possible. But the dimmer member of Gamma Delphini is famous because
it does have a greenish sheen to it! The reason for this contradiction is that the green-color of
the star is an optical illusion. It is the bright yellow-white of the star next to the dimmer bluish
companion that tricks the human brain in seeing the dimmer companion as green.
I always thought that Gamma Delphini should have a cool common name associated with it.
Last month, I was looking through Edition 6 of “Objects in the Heavens” by Peter Birren that I
just received in the mail. I noticed that under his comment section for Gamma Delphini he
simply states “Lemon + Lime”. Perfect! I will now forever call this double-star “The Lemon and