[sac-forum] Call for Observations
- From: "AJ Crayon" <acrayon@xxxxxxx>
- To: "SAC Forum" <sac-forum@xxxxxxxxxxxxx>
- Date: Mon, 16 Jul 2012 19:41:54 -0700
This is the August CFO that includes Ophiuchus. Also included are the lists
for next two months - Cygnus and Cepheus. They have been inserted this way
because of the news letter schedule. Yet the attempt here is to stay up to
date and on schedule with CFO.
So with that in mind I'm looking for observations from Ophiuchus. Yes I know
the weather hasn't cooperated but please go back to prior years and scour your
list for the included objects. The other two constellations have been included
for you observation planning.
This will mark out fourth time through Ophiuchus. There are many dark nebula
located here, but also a nice selection of deep sky objects that also may
include a surprise. Keeping mostly south of the celestial equator start with
the open cluster Do 27. Do you consider this cluster bright, faint, large or
small? How many stars do you see and is there any detectable nebulosity? Next
try the double star omicron Ophiuchi. Are any colors detectable? Now on to
one of the more interesting objects, M 9. Please give us a nice description
of this globular cluster. Now just to the west is a prominent dark area
labeled B 64 for Barnard’s Dark Nebula. Note size, shape and any stars that
are involved. This is followed by another dark nebula B 259 and is located 50’
southeast of M9. Which of these 2 dark nebula is darker? Note in the SAC
database dark nebula have a magnitude of 79.9. This is because they have no
magnitude. Getting back to globular clusters try giving the Herschel 400 entry
NGC6356 a try. It should be bright and large, but what else do you detect?
Getting closer to the celestial equator, is another globular cluster also a
Herschel 400 entry, NGC 6517. It isn’t as big or bright as the last but give
your description a good shot. The next globular is M 14, which should be nicer
than the last 2 but how does it stack up against M9? Don’t forget to describe
what you observe. Our final object, the only one north of the celestial
equator, is the surprise. It is NGC6384, a fairly bright barred spiral galaxy.
After describing the galaxy take note of the stars in the field of view. In
my old 8” there were 50 stars from 7th to 13th mag limit of the telescope.
I’ll have to count them in my Dobsonian.
For the September column we will take on Cygnus – again. There are a lot of
different objects here and we will look at almost every kind, save galaxies.
This will take us around most of the constellation so enjoy. For starters take
a look at the lovely triple star 17 Cygni. These stars are bright, widely
separated and have some color contrast. What colors do you see? Next are two
dark nebula, Barnard 145 and 146. Describe these two and including their shape
and opaqueness. Which of them is the darker? Moving a little to the north is
NGC6866, an open cluster. It is pretty rich but how else would you describe
this nice gem? A little more to the northeast is the next open cluster
NGC6811. This one doesn’t have quite as many stars but is larger. Now for an
interesting piece of NGC history for the next object, a planetary nebula. It
has two designations NGC6766 and NGC6884. The difference in the number is due
to an error in RA, for 6766, when originally catalogued. Note it is a small
faint planetary so a finder chart may be helpful. This next open cluster,
NGC6895, appears to be a nice clump of stars in the Milky Way. How clumpy does
it look to you? Now to another dark nebula - Le Gentil 3. It is located at RA
21 00.0 Dec +51° 00 and has no magnitude but that’s normal for dark nebula. It
is huge, possibly visible to the naked eye and sometimes called the Funnel
Cloud. Going back to open clusters is NGC7031 that is said to look like a
cluster of multiple stars. Does it look like this to you in your telescope
and, by the way what type of Trumpler code would you supply? NGC7039 is the
next object, another open cluster and is much larger than the prior open
cluster. Finally we get to the last object NGC6997 located in the eastern part
of the North American Nebula. How much nebulosity do you see here along with
the cluster?
For October the scheduled constellation will be Cepheus the king. For some of
these objects you may need a finder chart or star atlas, nothing elaborate.
Something like Uranometria should do for a star chart. As expected most of
these objects will be open clusters, so for each include your interpretation of
the Trumpler type. Starting out look for the cluster NGC7055. Actually it is
more like a poor asterism because it is small and faint. Next is our northern
most object, Berk 93 another open cluster. It can be found at RA 21 55.5 Dec
+63 56. I would consider this cluster small, faint and rich. What would you
call it? Then it is on to a planetary nebula with NGC7354. It is faint and
small. Can you see the ring structure? We now go back to open clusters for
the remainder of our list and we start with Berk 95 located at RA 22 28.3 Dec
+59 08. Its few faint stars should stand out. Now on to NGC7281 a fairly
large cluster with some rather faint stars. Berk 94 is next, the southern
most of this list. It may be found at RA 22 22.9 Dec +55 53 and should be easy
to find. The second to last is NGC7352 a rather large compressed grouping of
stars. Then last is from a list of interesting open clusters as most are
small, faint and rich. It is Biur 3 located at RA 23 15.2 Dec +60 27. Does
this cluster match the description?
AJ Crayon
Phoenix, AZ
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