Ottawa Centre Monthly Observing Challenges
Beginning in 2007, Ottawa Centre has introduced a new item to its monthly meetings: an observing challenge object. Each month the centre will post a description of an interesting object. Members are invited to observe, sketch, photograph, or otherwise learn about this object. At the subsequent monthly meeting, an agenda item will provide an opportunity to share your thoughts, photos, sketches, or comments.
March 2007:
Lunar:
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Deep Sky:
IC 2177 and Vicinity (by Rick Wagner)
Commonly referred to as the Seagull Nebula, IC 2177 will be a challenging target for a 6-8” scope under fairly dark skies. It extends about 2.3 degrees from the open cluster NGC 2335 in the north to the emission nebula Cederblad 90 in the south. There are several very nice cascades or strings of stars involved or nearby. |
 The head of the seagull is the fairly bright emission nebula vdB93 which shows a very nice dark lane on deep images, though I didn't see it visually in my 8” Dobsonian. Give it a try. The real challenge here is the presence of the bright star in the centre. Cederblad 90 is the other bright area at the southern tip of IC 2177. It's a few arcminutes in diameter and seems to be fairly featureless, centred on an 8th magnitude star. Immediately to the west of it is a dark nebula that shows up on photographs – I can't find any evidence that it has been catalogued. Is it detectable visually? Probably only with a large scope. NGC 2327 is another smaller emission nebula on the western edge of IC 2177. |
NGC 2335 is a fine open cluster, with about 30 to 50 stars visible, depending on your scope size. They range in brightness from an easy 10-12th magnitude, down to 16th magnitude – a challenge even in the FLO 16”. The cluster is rather loose but stands out quite well from its surroundings. It's about 8' in diameter.
There are also three other open clusters embedded in the Seagull, but they are very difficult. I perceived Collinder 465 as a very slight increase in the background star density, but Collinder 466 and Berkeley 76 were both invisible. While you're in the area, be sure to hunt down the two very nice open clusters NGC 2353, two degrees east, and M50, about three degrees to the NNW. |
Previous Challenge Objects
| January 2007 | IC 2169, Melotte 20 |
| February 2007 | IW 78, IW 69, Sigma Orionis, Lambda Orionis, NGC 2362 |
Header Image Credit
The icon leading to this page and image in the header are images of globular cluster M3 produced by Ottawa Centre member Albert Saikaley. This was chosen as the icon of the "Challenge Objects" section because the globulars are within the range of beginners with modest telescopes, yet advanced amateurs are still challenged by teasing out the spectacular colours and details such as those in Albert's image.
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Modified: April 10, 2007 |