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Old 30-09-2009, 02:36 PM
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ngcles
The Observologist

ngcles is offline
 
Join Date: Dec 2006
Location: Billimari, NSW Central West
Posts: 1,664
No OIII !!

Hi Paul,

Quote:
Originally Posted by Lismore Bloke View Post
Les, I did a search on that nebula complex. This site discusses the area:

http://lists.visualdeepsky.org/piper...ne/001805.html

I will definitely be having another look when the moon goes. Nor sure how much I will see from the suburbs though. An OIII filter may be needed.
I only just noticed this comment here -- particularly about the OIII filter. The small complex of bright nebulae here are all of the reflection variety so an OIII won't help -- in fact it will kill them completely. Try it if you've got one by all means -- but it won't help. The nebulae here are pretty small but one or two have strange shapes close in to the illuminating stars. Basically they are nacent moderate/low-mass stars emerging from the womb. Several of these stars are variable as they are still settling down to main-sequence life. These include R Cor A, S Cor A, T Cor A, TY Cor A among others.

There is a nice wide-field image here that shows the whole complex:

http://image14.webshots.com/15/1/1/8...4qvthbw_fs.jpg

There is also an area within Bernes 157 that at has an (about) 20 arc-minute diameter true field is essentially devoid of stars down to mag 14 -- it's a virtual hole in the sky centred at about RA 19 04 13 and Dec -37 16 31 and inky black.

I got a funny story about that field actually but will save that for another time ...


Best,

Les D
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