#1  
Old 30-01-2010, 09:20 PM
Paddy's Avatar
Paddy (Patrick)
Canis Minor

Paddy is offline
 
Join Date: Jun 2007
Location: Strangways, Vic
Posts: 2,214
Strangways observation notes 14/1/2010

Dear all,

Here are some notes from my session on 14th Jan., inspired to follow up on some of the observations reported by Sab and Malcolm.

Seeing was moderately good and transparency excellent. Thanks for reading.


Telescope 400mm f4.9 tri-dob reflector
Eyepieces 28mm UWAN, 17,13,9 mm Naglers, Paracorr
Guiding: Night Sky Observer’s Guide (NSOG),

Messier 79 GC in Lepus 175x. A very interesting GC. There is quite a distinct core which appears slightly elongated N-S. Some faint resolvable stars in front of the haze of the central core. Around this central core is a gap in resolvable stars. Further out from the core is a ring of 8-10 resolvable stars. Apart from an area of haze and stars projecting from the GC to the S, the GC is about 7’ wide, the ring of resolvable stars is about 3’ in dia. The core seems to be about 2’x1’. Another ring of stars is apparent around the GC itself – 9-10 of these are very easily resolved, but there is a spattering of fainter stars in this outer ring. The strand of stars and haze branches off from the western side of the GC and heads south seems nearly as wide as the GC itself, perhaps 5-7’ long. I wonder if this is part of the GC pulled out during a turn through the plane of the galaxy, or if it is a foreground phenomenon.

IC 418 Pne in Lepus. 175x. A beautiful object, with quite bright bluish central star illuminating the purplish disc of the nebula. Dia <30”. Much brighter with averted vision. I have an impression of some darker patches in the dsic when viewed directly. These disappear with averted vision as the nebula brightens. 250X enhances brightness and sense of colour. I also have an impression of a narrow dark channel between the star and the disc of the PNe. OIII filter shows fainter ring of haze around the outside of the nebula. UHC filter also shows the nebula to have softer edges than apparent without a filter.

NGC 1888/9 GX in Lepus. 175x A nice pair of faint galaxies. 1888 is the larger of the 2 and is listed as visual mag 11, 1889 is listed at 13, but as it is smaller, it seems to have greater surface brightness. 1888 is an edge-on spiral oriented roughly N-S and 1889 is a small smudge appearing to be heading into the spiral from the east. Although they are very close, a dark space between them is visible. I have the impression of a distinct nucleus in 1889, but not in 1888 although it is brighter in the centre. 250x improves the view. I estimate that 1888 is about 5’x’1, 1889 <1’ dia.

NGC 1535 Pne in Eridanus 250x Bright blue disc with soft edge with quite bright central star. I have the impression of an inner and outer shell. The outer shell is about 1’ across, the inner shell is about half the radius and a bit brighter. UHC filter shows the firm edged inner shell and somewhat softer outer shell. I also have the impression of a flattened inverted s-shaped brightness running through the centre of the nebula, but I’m not really sure of this. OIII filter enhances the appearance of the two shells and the inner sphere looks somewhat lumpy, with quite small lobes.

NGC 3132 PNe in Vela 250x The Eight Burst Nebula. I really like this one. A bright central star, the nebula is elongated roughly SE-NW. A distinct bluish hue. A dark annulus surrounds the central star with a brighter ring around the annulus. The darker annulus is more prominent to the N of the central star. UHC filter shows the annulus as a little wider than without. OIII filter makes the darker inner ring even more distinct. The SE edge of the bright outer ring is more distinct than the NW and it gives the impression of a jellyfish heading to the SE.

NGC 2792 PNe in Vela 250x. Much smaller Pne. Smooth round haze, no central star or impression of structure. OIII filter – the nebula seems to have a grainy brightness on the southern side.

At this point, I am closely circled by a small bat. I love the way they do that – perhaps after any mosquitoes that I may attract.

NGC 2438
At this PNe in Puppis. 250x A lovely bit of sky with crowding of stars of the OC M46 around the PNe. It appears to have a bright central star, but NSOG informs me that this star is part of M46 and that the PNe’s star is too faint at mag 17. There is quite a wide dark annulus around the visible star and a bright ring around that. UHC filter confirms the sense of the dark annulus unless. OIII filter gives the impression of notchiness at the junction of the dark annulus with the outer ring.

Mars 175x North polar cap is quite distinct. There is a small dark wedge immediately to the south of the polar cap. A larger, fainter area of patchy darkness extends from just to the south of the cap about a third of the way across the disc. I note a paler orange area on the western limb of the disc just below the dark line to the south of the polar ice cap. This is the most detail that I’ve ever seen on Mars – it actually looks like it does in the pictures!
Reply With Quote
  #2  
Old 30-01-2010, 09:44 PM
pgc hunter's Avatar
pgc hunter
Registered User

pgc hunter is offline
 
Join Date: Feb 2009
Location: Renmark, SA
Posts: 2,980
Good stuff mate! You weren't imagining the features you saw in NGC 1535, as I can confirm that the interior of the inner section does feature distinctly uneven brightness. This is one to catch in excellent seeing and go insane on the magnification!

You saw IC 418 as purplish....sounds like you are getting the colours which gave it the moniker "Raspberry Nebula". Interesting observation here, it seems it presents a different colour to whomever observes it, I see it as white, and I think it was Malcolm who reported a bluish hue. Could be that our eyes are more/less sensitive to certain wavelengths, or maybe sky darkness or equipment plays a role?
Reply With Quote
  #3  
Old 31-01-2010, 11:07 AM
barx1963's Avatar
barx1963 (Malcolm)
Bright the hawk's flight

barx1963 is offline
 
Join Date: Nov 2008
Location: Mt Duneed Vic
Posts: 3,978
IC 418 seems to be a strange one. Sue French reports it as turquoise in a 4" scope and states that reddish colours are more apparent in larger scopes.
Anyways, enjoyed reading your report Paddy.
Reply With Quote
  #4  
Old 31-01-2010, 12:19 PM
orestis's Avatar
orestis
Registered User

orestis is offline
 
Join Date: Jun 2009
Location: southern highlands, Australia
Posts: 679
Very nice report Patrick, Enjoyed reading it.


I'm glad you got a good view of mars,reminds me of the other day when i had perfect seeing conditions and it looked like the pictures, Amazing.

M79 seems like an interesting glob might observe it when these clouds clear up.

keep up the good work
Orestis
Reply With Quote
  #5  
Old 31-01-2010, 01:38 PM
Paddy's Avatar
Paddy (Patrick)
Canis Minor

Paddy is offline
 
Join Date: Jun 2007
Location: Strangways, Vic
Posts: 2,214
Thanks all for the responses. Quite interesting the colour thing. I would have thought that we should not be able to see any colour in something so faint. And I have no idea why it would seem different to various observers.
Reply With Quote
  #6  
Old 02-02-2010, 04:05 PM
Rob_K
Registered User

Rob_K is offline
 
Join Date: Oct 2006
Location: Bright, Vic, Australia
Posts: 2,158
Great report Patrick, some interesting objects there! Yeah, funny about colour perception, so many variations...

Bats buzz me quite often during observing in the back yard. Sometimes they seem perilously close, and I hope that none of them have wonky radar, LOL!

Cheers -
Reply With Quote
  #7  
Old 02-02-2010, 04:32 PM
pgc hunter's Avatar
pgc hunter
Registered User

pgc hunter is offline
 
Join Date: Feb 2009
Location: Renmark, SA
Posts: 2,980
Quote:
Originally Posted by Rob_K View Post
Great report Patrick, some interesting objects there! Yeah, funny about colour perception, so many variations...

Bats buzz me quite often during observing in the back yard. Sometimes they seem perilously close, and I hope that none of them have wonky radar, LOL!

Cheers -
One night I spotted a huge rat creature running along my fence, I aimed the red light at it to see what it was and it looked back at me....with its two red beady eyes.....yep almost crapped my daks right there.....

Turns out it was a possum that frequents the area coming to feed on the food scraps that my mum chucks over the fence!
Reply With Quote
  #8  
Old 02-02-2010, 08:38 PM
Paddy's Avatar
Paddy (Patrick)
Canis Minor

Paddy is offline
 
Join Date: Jun 2007
Location: Strangways, Vic
Posts: 2,214
Quote:
Originally Posted by Rob_K View Post
Great report Patrick, some interesting objects there! Yeah, funny about colour perception, so many variations...

Bats buzz me quite often during observing in the back yard. Sometimes they seem perilously close, and I hope that none of them have wonky radar, LOL!

Cheers -
Thanks, Rob. Regarding the bats, it amazes me too how close they get .
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 09:45 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Advertisement
Testar
Advertisement
Bintel
Advertisement