By Dave Fuller on
7/23/2014 7:34 PM
There are various ways to find objects in the sky. Some are easy, such as, "Point your telescope right at Saturn / Albireo / the Moon." Others take a bit more effort. Ophiuchus is a large constellation, just above the better-known Sagittarius and Scorpius. While large, it only has 3 stars of magnitude 2, but a total of 9 at 3rd magnitude or brighter. So city observers may have some challenges, but suburban viewers can likely navigate their way around this large "doctor in the sky" with little difficulty.
There are a number of Messier objects in Ophiuchus, along with some great double stars and other clusters. But two that are right near each other are Messier 10 and Messier 12, globular clusters both. While relatively bright as globulars go, they aren't exactly right next to any 2nd or 3rd magnitude stars, so there are a few techniques required to find them.
One is by drawing a few imaginary lines in the sky that intersect where the clusters are located. This graphic below shows how t that can be...