John Hothersall
30-05-2018, 07:29 PM
SPX350 F9.1, ASI290, Baader LRGB filters.
Some more planatary nebulas little imaged because they are small. Variable seeing, some good seeing with NGC 5315 compared to Hubble ST image and some with not so good seeing as in the Boomerang neb, sometimes called the Bowtie nebula, which is not listed as an NGC and is the coldest place known so far at 1K. NGC 3918 called the Blue planetary looks like a ball of wool. NGC 2867 looks like a snail shell, we really need to rename these in the CCD/CMOS era.
If the PN is less than 12th mag and 0.3 arc mins I can usually see something, and 10th mag at 2 arc mins is also just about visible in the SharpCap preview. The Helix nebula was not visible with low surface brightness.
Regards, John.
Some more planatary nebulas little imaged because they are small. Variable seeing, some good seeing with NGC 5315 compared to Hubble ST image and some with not so good seeing as in the Boomerang neb, sometimes called the Bowtie nebula, which is not listed as an NGC and is the coldest place known so far at 1K. NGC 3918 called the Blue planetary looks like a ball of wool. NGC 2867 looks like a snail shell, we really need to rename these in the CCD/CMOS era.
If the PN is less than 12th mag and 0.3 arc mins I can usually see something, and 10th mag at 2 arc mins is also just about visible in the SharpCap preview. The Helix nebula was not visible with low surface brightness.
Regards, John.