The Mekon
07-10-2015, 07:42 PM
For the past few weeks I have been regularly checking three stars that form a small triangle in Capricorn. These stars, Omicron, Pi, and Rho can be seen together in an eyepiece yielding a field of view of around 1 degree.
Omicron is an easy even double, resolvable at around 50x in virtually any telescope and is very attractive.
Pi is much tougher, a 5th mag primary with an 8th mag companion at around 3" separation. I can just detect this at around 120x in my 106AT APO refractor.
Then there is Rho. In itself a very wide double but the main star is awful tough. I have found that I can detect the presence of the 9th mag companion with around 150x, but to make sure of the observation I need around 300X which is maxing out my 695mm FL refractor. The separation can be no more than 1" - I reckon splitting this star is much tougher than Antares, but last night I can confirm that I successfully split this one for the second time in a week in the small refractor - the heat has brought some good seeing in our area.
In between first looking at these stars with my 106AT, I masked off the 18" to 7" and confirmed all the above observations.
Omicron is an easy even double, resolvable at around 50x in virtually any telescope and is very attractive.
Pi is much tougher, a 5th mag primary with an 8th mag companion at around 3" separation. I can just detect this at around 120x in my 106AT APO refractor.
Then there is Rho. In itself a very wide double but the main star is awful tough. I have found that I can detect the presence of the 9th mag companion with around 150x, but to make sure of the observation I need around 300X which is maxing out my 695mm FL refractor. The separation can be no more than 1" - I reckon splitting this star is much tougher than Antares, but last night I can confirm that I successfully split this one for the second time in a week in the small refractor - the heat has brought some good seeing in our area.
In between first looking at these stars with my 106AT, I masked off the 18" to 7" and confirmed all the above observations.