2013 11 01 – Cr 26 (Mel 15)
Within the center of IC 1805, the Heart Nebula (Sharpless 2-190), lies its open star cluster Melotte 15 (also known as Collinder 26). It’s a cluster measuring 22 arcminutes across and consists of 40+ stars with a Trumpler Classification of III 3 p.
Eyepiece sketch created with an observing template on white printer paper, a super-fine black felt-tipped artist pen, #2 pencil, 0.5mm mechanical pencil and a blending stump. The sketch was scanned in Photoshop, inverted and contrast adjusted to match eyepiece view.
Negative version
Have a look at this fabulous image of the entire Sharpless 2-190 complex by Barry Schellenberg. Collinder 26 is seen in the center of the heart while open cluster Markarian 6 is nestled in its SW edge. The bright nebulosity at the bottom of the heart is emission nebula IC 1795 (NGC 896) with NGC 886 (Stock 6) consisting of a small grouping of 11th – 12th magnitude stars.
The nebula complex is just 5 degrees NE of the Double Cluster in Perseus, making it a fairly easy target to find. For a really nice tour, start at the Double Cluster and then hit Basel 10 to make out the small handful of stars in the small 2-arcminute open cluster. If you have a smaller telescope, skip Bas 10 and head NNW to Stock 2, a large open cluster measuring 60 arcminutes across. From there, you’ll see a small strand of 8-9th magnitude stars that form Mrk 6 before locating Cr26. You’ll have better luck viewing nebulosity within the emission complex with an OIII or UHC filter. I was able to see faint nebulosity with my OIII in Cr26 as well as the brighter sections of Sh 2-190 when panning the area.
PCW Memorial Observatory - Erika Rix 