Astrophotography by Anthony Ayiomamitis

Deep Sky Object Image Gallery

Open star clusters are widely distributed in our galaxy and represent a loose collection of stars which number from a few dozen to a few hundred stars and are weakly-held gravitationally. Perhaps the three most famous such open clusters are the Pleiades (M45) in Taurus, the Beehive (M44) in Cancer and the double cluster in Perseus. They are all characterized with a handful of hot and white prominent stars and nebular material surrounding these stars.

Note: The open cluster Melotte 15 at the center of the expansive emission nebula IC 1805 (Heart Nebula) in Cassiopeia was discovered by British astronomer Philibert Jacques Melotte (1880-1961) and which was published in 1915 along with his catalog of 245 deep-sky objects comprised of open and globular clusters identified while studying the Franklin-Adams plates. Melotte 15 is comprised of OB-association hot young stars spanning approximately 30 light-years across and which illuminate and sculp the excited ionized hydrogen in the immediate area. The cluster lies 7,500 years away and has been estimated to be quite young at a mere 1.5 million years old. A small sample of the stars which comprise Melotte 15 are characterized with a mass fifty times that of the Sun.

Please click on the image below to display in higher resolution (1200 x 900)

Image Details
Melotte 15 - Open Cluster in Cassiopeia
Imaging Details
Melotte Number:
15

Common Name(s):
N/A

Other Designations:
IC 1805, Col 26

Object Type:
Open Cluster

Object Classif:
II 3 m

Constellation:
Cassiopeia

RA / Dec:
02h 32m 42s /
61 27' 48"


Distance:
7500 light-yrs

Object Size:
20'

Magnitude:
6.5


Date:
Oct 18-19, 2012
23:10 - 03:30 UT+3


Location:
Athens, Greece

Equipment:
AP 305/f3.8 Riccardi-Honders
AP 1200GTO GEM
SBIG ST-10XME
SBIG CFW10
SBIG LRGB filters
Baader H-a 7nm


Integrations:
H-a :  120 min (08 x 15 min)
Lum :  000 min (00 x 01 min)
Red :  000 min (00 x 03 min)
Green :  000 min (00 x 03 min)
Blue :  000 min (00 x 03 min)
Binning :  1x1 (Lum, H-a),
 1x1 (RGB)

Image Scale:
1.21" per pixel

Temperatures:
Ambient : + 20.0 C
CCD Chip : - 15.0 C

Software:
CCDSoft V5.00.201
CCDStack V1.6.0.5
eXcalibrator V3.1
Aladin V6
Photoshop CS5