[sac-forum] Call for Observations
- From: "AJ Crayon" <acrayon@xxxxxxx>
- To: "SAC Forum" <sac-forum@xxxxxxxxxxxxx>
- Date: Thu, 24 Apr 2008 10:36:55 -0700
I have enough observations for the Bowl of Ursa Major, thanks to observers like
Charlie, Dick, Joe and Ken. The article already exceeds the 2 page limit and I
thank our editor-in-chief for permitting our excess.
Don't feel left out with Ursa Major because here's the next 3 months. Note the
last one, Draco, hasn't been published -yet. This early announcement will give
us more to add to observing lists.
We've got weekends coming up and look forward to clear skies and good observing.
Call for Observations
There are about 40 objects in Coma Berenices that are in the Messier, 110 Best
NGC, Herschel 400 or the Caldwell lists. To this add one large naked eye
asterism. That is enough for many appearances of this constellation and this
is the first one. To begin with there are some good selections here for any
size telescope from a dark site, their magnitudes range from 9.4 to 10.4 as all
are, at least, on the 110 Best NGC list and near the Coma Star Cluster to boot.
Most are barred spirals, save two, so look for as much detail as possible not
only within the middle but in the arms. Try to work on estimating the size and
magnitude of each and then compare your results with published values. Keep at
this long enough and you will get a feeling about these dimensions and get
better and better at estimating. First one to review is NGC4274 and its
Saturn-like structure. Up near the Canes Venatici border is NGC4414, a late
spiral but what kind of detail can you observe in its middle? Next is NGC4494,
the sole elliptical. Continuing to move westward is the very elongated
NGC4559. Next, just to the east of the cluster is one of my all time
favorites, the spiral NGC4565 and an even more elongated galaxy. Can you
detect the central dark lane? Lastly, and moving away from the cluster is
NGC4725. Can you detect other galaxies in the field? With that we will have
many more enjoyable sessions to come.
The middle section of the Serpent, Hydra mostly made up of galaxies. The first
entry is 1.5° to the southeast of 5th magnitude SAO155588 and is the elliptical
NGC3091. Second is the almost round, barred spiral NGC3313, and at magnitude
11.4 is the faintest of the selections. Next is the almost edge-on spiral
NGC3717, is about 60' north of 5th magnitude SAO202553. Continuing the
eastward march is NGC3904 at magnitude 10.9. Then a scant 35' northeast is
NGC3923, which is the brightest of the selections at 9.8. Both of these
galaxies are elliptical. The final selection is the interacting pair NGC4105
and NGC4106.
Keeping with an extra month ahead because of monsoon the next selection will be
Draco. There is quite a bit here to choose from, especially since it crosses
many lines of Right Ascension. Here we'll keep to the region around the head
of the dragon and find them all, save one, galaxies. The magnitude range for
the galaxies is 9.9 to 12th. The first selection is NGC6140 a nice elongated
barred spiral. Next jump is to NGC6340 a nearly face-on early type spiral.
There are other galaxies in the field. Can you count and identify them? The
Draco Dwarf, UGC10822 and a member of the Local Group of Galaxies, is next and
its magnitude is listed as 9.9. Beware this can be misleading because its size
is 33.5'X18. 9'and that gives it a low surface brightness. You might try to
ferret out some detail with averted vision while waiting for a moment of good
seeing. Continuing on our way finds NGC6412 a barred spiral with some detail.
Again, try to get as much out of this one as you can. Our last galaxy is
NGC6654, at 12th mag. Not clear, to me, if it has some faint stars involved or
bright HII regions. What do you think? Finally comes an asterism named after
Fr. Lucian Kemble called Kemble 2 and located at RA 18h35.0m Dec +72° 23'. It
is 7th mag, 30' and forms a ''Mini-Cassiopeia'' like asterism. Mag 3.5 chi
Draconis is in the field. Perhaps why it has a 7th mag rating?
AJ Crayon
Phoenix, AZ
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