known as Segin . Located about 440 light years away , this blue-white giant shines from its post with an apparent magnitude of 3.38 . The queen ’ s notable stellar offerings continue beyond the five that define her most recognizable feature . Best viewed with a telescope , Eta Cassiopeiae is a beautiful binary star system with a yellow dwarf primary component that is much like our own star and an orange dwarf companion . Cassiopeia is also home to two stars in the very rare yellow hypergiant class - Rho Cassiopeiae and V509 Cassiopeiae . Although they are each located thousands of light years from Earth , their extreme luminosity keeps them visible to the naked eye . A quick tour of Cassiopeia ’ s deep sky offerings has to begin with the open cluster Messier 52 . Although it can be enjoyed with binoculars , a moderate-sized telescope will reveal it as a fan of faint stars that includes a couple of bright yellow giants – one of which pops out from the cluster ’ s southwestern edge . A far more remote open cluster is Messier 103 , which is best viewed through binoculars due to its loose structure . Located near Ruchbah , the cluster , which includes a red giant that truly shines in photographs , will manifest as a hazy V-shaped patch . Another treat is the “ The White Rose Cluster ,” which is also known as “ Caroline ’ s Rose Cluster ” because it was discovered by famed astronomer Caroline Herschel . The cluster ’ s pattern of bright stars and dark paths is similar to the curves and valleys of a blooming rose . The constellation also offers the Bubble Nebula , which is a diffuse nebula southwest of M52 ; the open star cluster NGC 457 , which has
COURTESY OF John O ’ Neill
The Bubble Nebula is a diffuse nebula located southwest of Messier 52 . Astrophotographer John O ’ Neill captured this image using an Explore Scientific ED127-FCD100 and an SBIG ST-10 XME camera through narrow band filters of Ha , Oiii and Sii . Exposure times were three 800 second subs through each filter .
COURTESY OF Mike Wiles
Astrophotographer Mike Wiles used an Explore Scientific ED152 f / 8 refractor telescope and a SBIG ST-8300M camera to capture this image of Messier 103 .
around 100 stars and is sometimes called the Owl Cluster or ET Cluster due to an eye-like pairing of two bright stars ; the irregular galaxy IC 10 , which is the only starburst galaxy in our local group ; and the Pacman Nebula , an emission nebula with an open cluster of brilliant blue supergiants at its core and several Bok globules .
Sky ’ s Up 9