Old 13-09-2008, 11:49 PM
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Crusader is offline
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Location: South Africa
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NGC 4755 (Jewel Box) description for log

Hi guys

I'm starting out on creating a detailed observing log with the aim of perhaps submitting it to the Astronomical Society of SA in order to get Observation Merit Certificates (for each 20 objects you observe you apparently get a certificate).

I have'nt done a detailed observation log before (aside from just listing the objects observed), so I'm not sure what details to include or whether I'm doing it right.

Can you guys perhaps take a look at my observation of NGC 4755 and provide me with tips on how to make it more complete/correct/useful?

The Jewel Box (NGC 4755) is very easy to locate to the SE of Becrux. The cluster as a whole is bright and easy to locate in the finder scope (5 FOV).

It is a small open cluster with irregular shape containing stars of varying brightness (mag 5.7 for brightest to mag 10 for fainter stars. Stars are well resolved.

Using the 10mm EP, 9 bright stars can be easily seen. With the 3 brightest forming a triangular shape pointing to the west. A very prominent orange coloured star is visible close to the centre of the triangular shape at the end of a row containing 2 other stars. These 3 stars form a row facing NE to SE. Lots of fainter stars are visible in the surrounding area.

Approximately 40 stars can be easily counted. Size of the cluster appears to be around 10 arcminutes.
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Old 14-09-2008, 12:15 PM
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Sounds great to me Crusader, the only suggestion of info to add would be telescope type, arpeture and focal length, seeing and transparency conditions, and I presume somewhere you have recorded the date and time. If your really keen you can include a sketch, I like sketching as it helps you to pull more detail out of an object you would not have seen otherwise. Well done on a nicely detailed report. Hope to see some more from you.
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Old 15-09-2008, 01:02 AM
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Thanks. I did record the telescope, time and viewing conditions etc. I just didn't think of including it here.

For those interested:
10" Orion XT10 f/4.7 Dobsonian
10mm Sirius Plossl (120x mag) 26' FOV
Trasparency and Seeing: Both 6/10

I even managed to do a sketch, although I'm not much good at that part yet.
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Old 15-09-2008, 10:01 AM
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Becrux ??

Hi Crusader,

Looks very good to me except in one respect (and this is an old chestnut for me) -- Be(e)crux ... Grrrrrr.

This star has a (sadly neglected) proper name -- it is Mimosa. Every time I hear it called Be(e)crux (and sadly I hear it a lot) ... it's lke fingernails down a blackboard.

Apart from that


Les D
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Old 16-09-2008, 08:17 PM
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Mimosa it is then! The chart I used as reference listed it as Becrux (shortened form of Beta Cruxis I assume).

I've changed my actual log to Mimosa... thanks for pointing it out!
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