Collinder 350 -- Open Cluster in Ophiuchus
A Remarkable-Unremarkable Cluster
The heavens are full of never-ending interesting objects. I do not care how long you have
scoured the heavens, there is always something new for you to enjoy. To me Collinder
350 (Cr 350), in Ophiuchus, is one such object. This Open Cluster was first brought to
my attention in an article by Sue French in her 2005 book “Celestial Sampler”. A quick
check of my records showed that I had never recorded notes, or possibly had never
seen, Cr 350. With a reported magnitude of 6.1 and only 1.4 degrees south of
Gamma Ophiuchi (third brightest star in the constellation), I was a bit surprised that the
two of us had never crossed paths.
I was impressed with how obvious the cluster was, when I viewed it at 27x with a
2.4-degree field-of-view in my 6.1-inch refractor. It was a nice collection of subtle
points-of light surrounded by a semi-circle of brighter reddish-tinged stars including a
sweet double (HD-162652 & HD-162651) -- of which one of the stars was orange and
other one white. It was also, immediately apparent why this delightful cluster had
escaped my attention in the past. Most of my life I have owed telescopes that provided
only limited fields-of-view. The stars of Cr 350 are not bright and cover an area larger
than the full moon. It is an object that would be easily missed in most telescopes even if
viewed at low power. Large binoculars or rich-field telescopes are the clue to good
views of this remarkable-unremarkable cluster.
scoured the heavens, there is always something new for you to enjoy. To me Collinder
350 (Cr 350), in Ophiuchus, is one such object. This Open Cluster was first brought to
my attention in an article by Sue French in her 2005 book “Celestial Sampler”. A quick
check of my records showed that I had never recorded notes, or possibly had never
seen, Cr 350. With a reported magnitude of 6.1 and only 1.4 degrees south of
Gamma Ophiuchi (third brightest star in the constellation), I was a bit surprised that the
two of us had never crossed paths.
I was impressed with how obvious the cluster was, when I viewed it at 27x with a
2.4-degree field-of-view in my 6.1-inch refractor. It was a nice collection of subtle
points-of light surrounded by a semi-circle of brighter reddish-tinged stars including a
sweet double (HD-162652 & HD-162651) -- of which one of the stars was orange and
other one white. It was also, immediately apparent why this delightful cluster had
escaped my attention in the past. Most of my life I have owed telescopes that provided
only limited fields-of-view. The stars of Cr 350 are not bright and cover an area larger
than the full moon. It is an object that would be easily missed in most telescopes even if
viewed at low power. Large binoculars or rich-field telescopes are the clue to good
views of this remarkable-unremarkable cluster.