[sac-forum] Call for Observations
- From: "AJ Crayon" <acrayon@xxxxxxx>
- To: "SAC Forum" <sac-forum@xxxxxxxxxxxxx>
- Date: Fri, 3 May 2013 10:13:32 -0700
Here's the observing lists. We need the observations from the first one, Ursa
Major east, by the 12th of this month. This gives us 2 weekends to get them
done and in to me for submission for the NL. I don't have observations of any
in the list for UMa so please take some time and get some observations done and
in to me in time for the NL.
Thanks for your observations and support.
The following month will be the second installment of Ursa Major and is called
Ursa Major east because it will cover galaxies in the eastern part of the
constellation. Actually the galaxy selections involve galaxies in and a round
M101. The first of these is NGC5422 located almost a degree to the northwest of
M101 and is an early type spiral considered to be bright, small and elongated.
The second galaxy gets closer to M101 in fact it is so close that parts of it
may be in the field at the same time. The galaxy is NGC5473 a roundish
elliptical on the Herschel 400 list. Can you see its brighter middle? The
next one is the brightest of the next three. It is NGC5485 considered bright
and roundish. It is paired with NGC5486 at just 6' to the north. It is faint,
small and a little elongated. I suggest going back to NGC5485 before going to
NGC5484 the next one. It is a mere 4' to the northwest. It's an elliptical
that is very faint, small and round. Now dip south about 0.5° to NGC5477 and
find M101 about 20' to the west of southwest. It is also faint and pretty
large. The last galaxy is on the Herschel 400 list and is the most southern on
this list. It is NGC5474 a late type spiral, bright and large. It's about 45'
southeast from M101. That's it the last of Ursa Major for now.
At the last minute I decided to make a change on this month's observing list.
What we will do is observe some of the brightest barred spiral galaxies in
Virgo to see what they look like in our telescopes. Yes we know what they look
like from the myriad of pictures taken by SAC imagers as well as those around
the country and planet, but what do they look like in our telescopes. Can you
see the brighter middle or the bar? What about the spiral arms? Most will be
described as bright and large and are in the Herschel 400 list, so this kind of
description can be left off. So here's the list in right ascension order.
That will start us with NGC4216, which is on the SAC Best of the NGC. It is
edge-on and has a brighter middle. Question is how much can you see? Second
galaxy is M 61 or NGC4303. It has had 3 super novae since 1926 and NGC4301 is
in the field. Now move on to NGC4527. This one has quite a bit of detail in
the middle. How much can you see? While speaking of how much can you see have
you been able to see the spiral arms as they wind around the bar? Don't forget
this on the remaining galaxies. The S-shaped spiral NGC4535 follows. Along
with quite a bit of detail in the middle, it is elongated in a position angle
of 0° or due north. Now one of the brighter galaxies is M 90. It is elongated
about 2:1 but what's the position angle? Do you notice anything different
about this one that makes it stand out from the others? Now another of the
brighter ones and last of the Messier entries is M 58. It is called a fine
compact spiral. How much do you agree or disagree? This next one, NGC4654,
seems to have something questionable about the middle. What do you see here
and it isn't the 3 stars nearby? The fairly round NGC4654 is next. How much
can your telescope resolve - the brighter middle, the bar, spiral arms? Take a
look at the roundish NGC4699 and see if you agree. The coarse spiral NGC5068
follows. It is listed as irregularly round but does this have to do with the
coarse part? Note that NGC5087 is in the field. Again, another reminder, that
we should be trying to determine how much of the spiral arms we can see and not
just these beautiful galaxies. Here's another fine s-shaped double arm spiral
- NGC5247. Checked my observing list for this one and it hasn't been seen so
I'm looking forward to this one not to mention all the others. Continue with
NGC5364. The description indicates it is round but the dimensions don't
support this. Which description best suites your observation? This galaxy is
also listed as peculiar with a reference to a small bright nucleus in a smooth
center with dark matter. Dark matter? Finally this last of the bright barred
gems is NGC5746. It is very elongated, almost edge-on, at almost 6:1. In
addition to seeing the spiral arms how much of the brighter middle did you see?
OK that's it but there are a few comments that need to be passed along. If you
observe these spirals in right ascension order, the order in which they were
described, your telescope will slew over 100°. That's a lot but not nearly as
much as if they were viewed in increasing magnitude order. Here the slew will
be over 240°. But, if you are crazy enough to try this here's the list in
increasing magnitude order - M90, NGC4699, M61, M58, NGC4216, NGC5247, NGC4535,
NGC5068, NGC5746, NGC4527, NGC4654 and NGC5364. Finally something reasonable -
the shortest order. Using this sequence you will slew your telescope less than
90°. So this list is shortest order NGC5247, NGC5068, NGC4699, NGC4527, M61,
NGC4535, NGC4216, M90, M58, NGC4654, NGC5364, NGC 5364 and NGC 5746. To
determine the distances took my computer 22 minutes and checked some
439,084,801 combinations. Don't know about you but I can't wait to check out
these magnificent barred spiral galaxies.
AJ Crayon
Phoenix, AZ
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