Observing-Challenges
From OttawaRasc
Ottawa Centre March 2010 Observing Challenge
Beginning in 2007, Ottawa Centre 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.
Note: Your webmaster has recently had trouble finding the time to publish the challenge objects quickly after the monthly meetings. This month we're trying a different format, reproducing the meeting slides more directly, with less editing and narrative, and hope that method may permit more timely publishing in the future.
Lunar: Crater BILLY & Rimae BILLY (Billy D)
by Murray Campbell
| Murray Campbell presented the Lunar challenge this month, Crater Billy, and the area surrounding it. |
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| "Highlands and craters near Grimaldi
May I introduce you to BILLY, item number 124 in Isabel Williams Lunar Observing Program. BILLY is not a bad chap, perhaps a bit of a Black Sheep as seen at the left edge in this “Astro Sketch of the Day” by Frank Mc Cabe. BILLY and its neighbours are Detectable with a good pair of Binoculars, Discernible in small telescopes, and the smaller impact craterlets and volcanic features are viewable in larger telescopes." |
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The crater BILLY and its nieghbour HANSTEEN are an Odd Couple of Craters. They are located in the Southwest within the Highland Fringes of OCEANUS PROCELLARUM and MARE HUMORUM to the south of BILLY. BILLY is of the Imbirum period and due to its 46 km size and albedo or the dark basaltic lava filled floor, it is immediately detectable in binoculars in contrast to the light-toned MONS APLPHA (HANSTEEN) and nearby similarly sized crater HANSTEEN. Coordinates 13.8°S 50.1°W Diameter 45 km Depth 1.2 km |
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Billy and the Kids - LPOD 02 March 2004 In this Lunar Photo of the Day, we can identify the craters HANSTEEN on the left; the light-tone “extrusive volcanic mound” of Mons Alpha , which is also known as “the Arrowhead”; and the dark lava filled crater BILLY. The bright mound HANSTEEN MONS ALPHA (The Arrowhead), has been determined to be younger than the both Billy and crater HANSTEEN Immediately beside BILLY, there are several other features including the small crater BILLY D from BILLY D courses a 70 km long rille, Rimae Billy, that extends south and then has a change of direction as it meanders along the lava plain. THE Challenge is to develop image scenes of the Area; The Odd Couple; and isolate Billy and the the rille Rimae Billy. |
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Deep Sky: NGC 2158
by Paul Comision
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Paul presented the Deep Sky challenge, NGC 2158. |
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NGC 2158 is a small and dense open cluster, often overlooked because of its proximity to the much more conspicuous M35. Technically an Open cluster, it resembles a Globular with its bright, dense core. (We distinguish Globular Clusters from Open Clusters by more precise methods than their appearance. Most importantly, Globular Clusters are very old, while Open Clusters are usually very young.) |
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