#1  
Old 24-08-2014, 06:50 PM
pgc hunter's Avatar
pgc hunter
Registered User

pgc hunter is offline
 
Join Date: Feb 2009
Location: Renmark, SA
Posts: 2,938
Observing Report August 22-23, 2014

Finally had some clear skies at long last so did some observing after work. Getting home from work at 10:30pm meant that the 8" was the weapon of choice, as it is lightweight and sets up in 2 minutes. Basically did a half-night both nights after work. Thursday morning had some decent seeing, while Friday was still alright but not quite as good. Transparency was a little bad to start off with on Thursday, but improved rapidy. Friday was better in this regard. Being in the middle of galaxy season, it was time to spend some time in the galaxy strongholds of Sculptor, Fornax, Grus and Eridanus.

Thursday, August 22, 2014

Scope: 8" F/6 dob
Time: 12:30am-4:30am
Seeing: Ant. II
Transparency 3-4/5

* NGC objects magnitude obtained from NGC IC project.
* SB = surface brightness, obtained from Messier45.com
* On the Antoniadi seeing scale, I = best, V = poorest


NGC 253
GX, Scultpor, Mag V= 7.2, SB= 12.3

Always a favourite. Could already see some mottling in its central regions at 54x. Two foreground stars were visible near the centre and about halfway to the SW end. Using 92x enhanced the mottling and could hint at some dark lanes near the core region. At this magnification the galaxy stretched perhaps a little over 3/4 of the FOV (using Vixen LVW). A faint star was seen at the SW extremity.

NGC 288
GC, Sculptor, Mag V= 8.1

While in the area I decided to check out this globular. Rather faint at 54x and somewhat loosely packed. Lacks the tight spectacular core of clusters such as 47Tuc and NGC 2808. Approx a dozen stars were resolved, mostly at the W and S edges, with some across the granular core. Increasing magnification to 150x increased the number of resolved stars to about 3-4 dozen. The core appeared strongly granular. The bulk of the resolved stars form an "L" along the S and W edges, seemingly "cradling" the core. Increasing power to 240x yielded only minimal improvement, with only a few extra resolved stars.

NGC 247
GX, Sculptor, Mag V= 9.2, SB= 13.7

This one I has eluded me in the past owing to its low surface brightness. I believe I was not able to see it with my old 10" GSO dob. Faint at 54x, ofcourse only the central regions were visible, elongated roughly N-S at a ratio of 3:2. A mag 9.6 star lies at the southern end. Using 92x provided more contrast, but still faint and a mag 12.2 star was seen at the western edge of the core region.

NGC 1365
GX, Fornax, Mag V= 9.6, SB= 13.6

This galaxy should be THE poster child for the argument against light pollution. One of the biggest, brightest and most beautiful barred spirals in photos, from a suburban sky, it is anything but! Small, elongated 2:1 compact core at 92x, slightly elongated NNE-SSW. A stellaring was seen in the core. No hint of spiral structure whatsoever, just a faint, amorphous haze surrounding the core.

NGC 1232
GX, Eridanus, Mag V= 9.9, SB= 13.9

Faint roundish glow at 92x, slightly condensed centre. A grand object in astrophotos, but not much to see under suburban skies.

NGC 1300
GX, Eridanus, Mag V= 10.4, SB= 13.8

Exhibited a tight, diffuse circular core at 92x with faint narrow streaks extending ESE-WNW from the core. This is in fact the central bar of the galaxy, but no hints of the spiral arms were seen. At 150x I suspected a stellaring in the core.


Uranus
Spent some time on Uranus and Neptune to take advantage of the seeing. Some people say they can see albedo shading and bands on the planet, but I am a little suspect. At 342x, I did see limb darkening, but nothing on the planet itself that I would call concrete evidence of actual planetary features. I seemed to get the illusion of varying albedo, but I can only put this down to the variable seeing and the visual "background noise". In my opinion the angular size of the planet is just too small and too affected by even mild turbulence to confirm detection of any features, at least in this aperture range.

I did however pick out Titania and Oberon, visible intermittently as the seeing came and went.

Neptune
Very tiny, and much to my excitement spotted Triton at 342x. I would rank Triton to be actually easier than the Uranian moons.

Unfortunately, the version of Cartes Du Ciel I had did not show either Uranus or Neptune's moons so I had no way of confirming what I was seeing was infact the moons. A new version of CdC was available and downloaded that, and to my delight it now shows not only Triton and the Uranus' "big 4", but a whole host of other smaller moons now aswell! Kudos to the CdC team. This was the only thing missing from this otherwise excellent program.

------------------------------------------------------------------------

Friday, August 23, 2014

Scope: 8" F/6 dob
Time: 12:30am - 4am
Seeing: Ant. III
Transparency: 5/5

I was trolled by clouds at various stages during this session, they seemed to just appear out of nowhere, but luckily also disappeared quick. At one point the entire western horizon was socked in and nearly packed it up, but interestingly enough, all the cloud disappeared into thin air after perhaps only 30 minutes.

NGC 7606
GX, Aquarius, Mag V= 10.8, SB= 13.5

Fairly faint, elongated 2:1 smudge at 54x orientated NW-SE. A star was seen at the SE end. A mag 12.1 star lies approx 2.5' SSE of the centre and a fainter 12.8 mag star lies a similar distance to the NNW. Slightly condensed at 92x and increasing the magnification to 176x revealed a diffuse core surrounded by an elongated 3:1 halo.

NGC 7090
GX, Indus, Mag V= 10.7, SB= 13.3

A fairly faint streak of light at 92x with a mag 12.3 star located just north of the northern end. A magnification revealed a stellaring in the core.

NGC 7424
GX, Grus, Mag V= 10.5, SB= 14.9

This is a large face on spiral and as such, a painfully low surface brightness object. A small, faint, diffuse and weakly condensed core was seen at 92x. No hints of any surrounding haze. A mag 12 and mag 13.5 star pair resides approx 3.5' north of the core.

IC 5332
GX, Sculptor, Mag V= 10.6, SB= 14.2

A similar face on spiral to NGC 7424. Messier45 gives IC 5332 a higher surface brightness, but to my eyes, IC 5332 is the fainter object. A very faint amorphous haze at 92x, located roughly midway between a mag 10.1 star 4.5' to the SW and a mag 12.6 star to the NE. A mag 7.2 star 12' to the SW proved to be distracting in observing this galaxy.

IC 5267
GX, Grus, Mag V= 10.5, SB= 13.5

Fairly bright at 92x with a tightly condensed central region surrounding a stellar core. A fainter, slightly elongated halo in direction NNW-SSE was seen at 92x.

NGC 7462
GX, Grus, Mag V= 11.7, SB= 13.4

A small, relatively bright narrow streak at 92x, seemingly "attached" to a mag 10.8 star at its western end. The centre appeared slightly brighter at 150x, with the brightness tapering off towards the ends. A mag 6.8 star lies 11' to the east and a nice mag ~11 double lies approx 4' west.


NGC 1097
GX, Eridanus, Mag V= 9.5, SB= 13.5

This is a lovely barred spiral. At 54x, it featured at bright, compact high surface brightness core with faint extensions orientated NW/SE, giving it a spindle-like appearance. Increasing magnification to 92x confirmed the extentions, which form the bar of the galaxy. A diffuse oval haze surrounds the core. I could intermittently detect a very faint "knot" or star at the NW end of the bar, I assumed it was a star at the very limit of vision. Increasing power to 150x, this feature was now appeared to be a diffuse knot, very faint and visible intermittently with averted vision. Following it up online the next day, it turns out that this little knot is actually the companion galaxy, NGC 1097A. Pretty happy to catch in the 8"! Curiously enough, this little galaxy does not appear in Cartes Du Ciel's PGC catalogue addon. Messier45 gives it a magnitude of 12.9 (doesn't specify whether its photo or V mag) while NED lists it at 13.78.


So that's it for now, good to get back out and stretch the legs of the 8", looks like I'll be doing it again next week if the forecast is to be believed
Reply With Quote
  #2  
Old 24-08-2014, 07:43 PM
DavidU's Avatar
DavidU (Dave)
Like to learn

DavidU is offline
 
Join Date: Jul 2007
Location: melbourne
Posts: 4,719
Excellent report Sab, great to see you at it again.
Reply With Quote
  #3  
Old 24-08-2014, 10:11 PM
barx1963's Avatar
barx1963 (Malcolm)
Bright the hawk's flight

barx1963 is offline
 
Join Date: Nov 2008
Location: Waurn Ponds Vic
Posts: 3,789
Nice report Sab. Very impressive work with the 8". NGC 1097A has always eluded me even with the 20", of course 50 yo eyes may have a lot to do with that! But you have motivated me to try again!!

Malcolm
Reply With Quote
  #4  
Old 25-08-2014, 09:57 PM
michaellxv's Avatar
michaellxv (Michael)
Registered User

michaellxv is offline
 
Join Date: Oct 2009
Location: Adelaide, Australia
Posts: 1,577
Nice to read one of your detailed reports again Sab. Hopefully a sign of things to come.
Reply With Quote
  #5  
Old 26-08-2014, 04:54 PM
pgc hunter's Avatar
pgc hunter
Registered User

pgc hunter is offline
 
Join Date: Feb 2009
Location: Renmark, SA
Posts: 2,938
Thankyou gentlemen. Malcolm, you should be able to pick up NGC 1097A in a 20", but it is very small and I thought it was simply an extremely faint star at lower powers. Digging deeper, I found that it measures only 48x30", very tiny. You may have seen it but mistaken it for a star. It's clear tonight, get out there!

Micheal, if this week's forecast comes off, I will be very sleep deprived by the weekend
Reply With Quote
  #6  
Old 27-08-2014, 08:25 PM
Paddy's Avatar
Paddy (Patrick)
Canis Minor

Paddy is offline
 
Join Date: Jun 2007
Location: Strangways, Vic
Posts: 2,208
Great report Sab. Re NGC 1365, I reckon that this galaxy has not looked great for a few years. I think there must be more sky glow with the solar maximum. I certainly remember seeing much more of it before 2011-12. Re people seeing banding on Uranus, "tell 'em they're dreamin'" I reckon.

1097 is a gem - well done getting 1097A with an 8", but then your eagle eyes...
Reply With Quote
  #7  
Old 31-08-2014, 07:32 PM
pgc hunter's Avatar
pgc hunter
Registered User

pgc hunter is offline
 
Join Date: Feb 2009
Location: Renmark, SA
Posts: 2,938
Quote:
Originally Posted by Paddy View Post
Great report Sab. Re NGC 1365, I reckon that this galaxy has not looked great for a few years. I think there must be more sky glow with the solar maximum. I certainly remember seeing much more of it before 2011-12. Re people seeing banding on Uranus, "tell 'em they're dreamin'" I reckon.

1097 is a gem - well done getting 1097A with an 8", but then your eagle eyes...
That's interesting, never thought that solar activity would affect skyglow. I always expected NGC 1365 to be brighter owing to its relative "fame" and impressive appearance in images.

As for Uranus.... I find it hard to believe that one could see detail on that, I mean it's so small and contrast would be so little that even very mild turbulence would wash out any features. Here is an interesting and heated thread on the subject: http://www.cloudynights.com/topic/38...bands-in-a-c8/
Reply With Quote
  #8  
Old 31-08-2014, 08:34 PM
Paddy's Avatar
Paddy (Patrick)
Canis Minor

Paddy is offline
 
Join Date: Jun 2007
Location: Strangways, Vic
Posts: 2,208
Quote:
Originally Posted by pgc hunter View Post
That's interesting, never thought that solar activity would affect skyglow. I always expected NGC 1365 to be brighter owing to its relative "fame" and impressive appearance in images.

As for Uranus.... I find it hard to believe that one could see detail on that, I mean it's so small and contrast would be so little that even very mild turbulence would wash out any features. Here is an interesting and heated thread on the subject: http://www.cloudynights.com/topic/38...bands-in-a-c8/
I'd never thought of it either until David Malin did a presentation on the colour of the sky and talked about the effect of solar activity - basically like a low level aurora - particles of solar wind exciting electrons in the hydrogen and oxygen atoms in the sky. He said it's like seeing everything in a bit of a soup. To me it coincided with La Nina and I thought it was humidity. Then he gave the talk and I have to say things have not got better since the sky dried out. Solar observing's great though!

Regarding the detail on Uranus, a case of averted imagination I reckon. 'Specially with an 8" scope as the bloke in that thread used.
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 05:36 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Advertisement
Celestron Australia
Advertisement
Meade Australia
Advertisement
OzScopes Authorised Dealer
Advertisement
NexDome Observatories
Advertisement
Bintel
Advertisement
Lunatico Astronomical
Advertisement
SkyWatcher Australia
Advertisement
Astronomy and Electronics Centre
Advertisement