Tuesday 27 January 2015

#63 Cassiopeia Summary 1: NGC Open Clusters

     I will say something about each and every deep sky object observed in this most wondrous constellation.  I began observations in August 2013, and had just a few objects left to finish in August of 2014.  Many of the comments have been taken from previous Monthly Summary blog entries, but there is a significant amount of new detail.  There are 29 NGC open clusters, and I will discuss them in numerical order.

oc 0103:  5'.  Brightest * mag. 11.  30 stars on a stem with a branch.  Haze at low x, with 4 *s.
oc 0110:  19'. Brightest * mag. 9.7.  83x shows 60+ *s in this large, bright group.  A bright orange * is following, and a wide double south of it, yellow and mauve.  Medium rich even under a 1st quarter moon.  A low x beauty.
oc 0129:  12'. Brightest * mag. 11. Large group seen well at 60x and 83x. 35 stars near a triangle, with more further.  Rich group.
oc 0133:  3'. Mg. 9.4.  4 bright *s form an uneven north/south line, seen well at 60x.  2nd * from the north is a close double.  13 *s counted in a small area at 250x.  Adjacent to 146 and King 14.
oc 0136:  1'.5.  Brightest * mag. 13. 8 stars resolved at 250x.  Haze at low x.  Very tight and faint.
oc 0146:  5'. Brightest * 11.6.  An 11.6 mag * sits at the center at 60x, surrounded by a faint hazy cloud.  125x resolves most members, with 35 faint *s counted at 150x.  Adjacent to 133 and King 14.
oc 0189:  5'. Brightest * mag. 10.9.  Medium rich, dense.  Near a mini-Cepheus, and oc 225.
oc 0225:  15'. Brightest * mag. 9.3.  40 stars at 83x.  Good for 6" and up.  Large and bright.
oc 0358:  3'. Asterism of 4 stars.  Faint group south, involved with a 2nd asterism.
oc 0366:  4'. Brightest * mag. 10. 4 bright and 4 dim stars at 200x.
oc 0381:  7'. Brightest * mag. 10. 30+ stars at 150x, resolved well.  Dense group.
oc 0443:  4'. Brightest * mag. 9.  At 125x I observed a mag. 9.5 orange * closely surrounded by a cloud of tiny, faint *s.  200x shows 12 *s immediately surrounding the bright one, but there are many more in a wider area, using125x.
oc 0436:  5'. Brightest * mag. 10.  Little brother to oc 457, it is very close and an easy star hop away.  Both objects seen together at low x.  30 *s at 150x. 

oc 0457:  Stunning object in virtually any instrument, this one does require a low to moderate power.  For my scope 83x was the ideal range.  I also saw it well in Deb's 6" at 84x.  Highlighted by 3 bright stars, it is a moderately rich group.  Worth coming back to often.  Makes a nice showpiece for star parties or beginning observers.  
oc 0559:  7'. Brightest * mag. 9.  100x resolves a rich, dense group.  Up to 250x shows about 50 *s.

oc 0581--M 103:  6'. Brightest * mag. 9.  Not an object to hurry over, especially with a 12".  Not as instantly likeable as M 52, nor as many stars, but it is still beautiful and quite rich.  The cluster remains bright, even at higher powers.  A yellow star on one end, an orange one near the middle and a triple on the opposite side of the yellow one make a nice beginning.  The cluster is quite dense but don't be put off.  Even a 6" shows the group well.
oc 0609:  3'. Brightest * mag. 14.  Located at 60x with averted vision, it is confirmed at 100x, but still haze.  125x begins to resolve this tiny cluster.  A challenging object to observe.
oc 0637:  3'. Brightest * mag. 8.  7 brighter *s seen at 100x, some in a curving line.  Fainter members resolve here with averted vision.  Up to 300x shows a circular, torque-shaped group with a dense knot in the preceding section.  There are 20 to 25 *s.
oc 0654:  Already rich and dense at 60x, the stars swarm around a yellow 7.5 mag. star.  This reminds me of a Berkeley cluster on steroids!  High power shows 30 faint members.
oc 0657:  7'.  Brightest * 7.1.  A dozen bright *s seen preceding a lovely bright, wide double, yellow and blue.
oc 0659:  6'.  Brightest * mag. 10.  Near a bright triangle of *s.  Curving line noted, encircling faint haze.  Two circles of stars, attached in the middle, with about 25 *s in their middle sections, mostly faint.  Resolved at 200x.  
oc 0663:  15'.  Brightest * mag.9.  An outstanding cluster in my 12" mirror!  Large and bright, I viewed it at 60, 100 and 125x.  Though a major showpiece in my scope, it is bright enough to be appreciated in almost any aperture.  A rich cluster, highly recommended.  Two pair of double stars, one on either side of the group, add interest.  Easy sweeping to 654 and 659.
oc 0743:  7'. Brightest * mag. 10.  Wedge-shape at low x.  Compact and medium rich.  Dense inner section resolves at 100x.
oc 0886:  14'. Brightest * mag. 11.  Framed by 2 *s, mag. 8.5 and 9.  12 cluster *s relatively bright, with many faint ones also.  25 *s counted in 2 wide lines.
oc 1027:  15'. Brightest * mag. 9.  Lovely at 60x, with a white mag. 7 * in the center, along with a 9.7 mag. pair.  Many other fainter *s surround these 3.  Large and scattered.  About 60 *s at 100x, mostly white.  There is a double line of *s, crescent-shaped and faint, following the main *.  Fine object.
oc 7654/M52:  16'. A deep sky wonder!  60x shows well. 125x resolves all. Also see Cz 43.
oc 7788:  4'.  Cone-shaped.  Pair with larger 7790.  20 *s at high power.
oc 7789:  25'.  One of the finest ocs!  For 6" or higher.  Do not miss!  Uncountable stars in 12".
oc 7790:  5'.  A must with a 12".  Middle of 3 clusters, including 7788.  Medium rich at high x.

...to be continued 
Mapman Mike



 


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