March 10, 2010
Exogazing 55 Cancri
To find 55 Cancri, start by locating Castor and Pollux. An imaginary line drawn from Castor to Pollux will point you to the middle part of Cancer. But extending that line from Pollux past Mars will lead you to M44, or the Beehive cluster of stars. Move up by little over 10 degrees up from that cluster and you'll see 55 Cancri.
At magnitude 5.95, binoculars would help a lot to spot 55 Cnc. What I recently learned is that Castor and Pollux is 4.5 degrees apart. I know this because they fit within my binocular's field of view (FOV) which is 4.5 degrees in diameter. Knowing this calibration has been a great help in star hopping with binoculars.
The illustrations show how it would look like if you use a binocular with 4.5 degrees FOV. If you don't use binoculars, just remember that your fist held at arm's length spans approximately 10 degrees in the sky.
There are many reasons that make 55 Cancri an interesting target for exogazing. It's an extrasolar system with the most planets to date--five known exoplanets orbiting around it. And its a binary star system 41 light-years away consisting of a yellow dwarf star and a smaller red dwarf star separated by over 1,000 AUs. Yes, it would seem unlikely that any planets would form around binary systems and yet here is 55 Cnc screaming with 5 exoplanets confirmed to be orbiting the primary star, 55 Cancri A (the yellow dwarf)!
When you finally spot the 55 Cancri system, revel in the fact that a pinpoint of light can denote entire worlds. Isn't it amazing? You see a starlight, and you can focus a thought to that point of light and the planets it foretells. That is the essence of Exogazing!
"Then felt I like some watcher of the skies
When a new planet swims into his ken"
~ John Keats
55 Cancri from Deep Fly