Go Back   IceInSpace > General Astronomy > Observational and Visual Astronomy > Observation Reports

Reply
 
Thread Tools Rate Thread
  #1  
Old 04-05-2011, 08:54 PM
pgc hunter's Avatar
pgc hunter
Registered User

pgc hunter is offline
 
Join Date: Feb 2009
Location: Renmark, SA
Posts: 2,939
Observing Report 26/4/11 - Galaxies, inc. Polarissima Australis

Well after months and months of nothing but clear nights on all non-weekend and non-holiday nights, I was finally paid my due. Even though there was a fair bit of murky haze earlier in the day, it seemed to gradually decrease during the evening. Seeing was a disaster though, even worse than the deplorable Metro trains service I have to suffer through every day, at times stars at even 167x wouldn't focus to anything I'd regard as crisp. Even so, the observations I made here have taught me a key thing about observing galaxies.

I found my 5mm LVW (267x) to be superior to the 8mm (167x) for increasing the visibility of faint galaxies, infact I'd say that the 5mm is becoming my weapon of choice for such objects even if the seeing is not cooperating. I tried using a 13mm with the barlow (205x), but that didn't quite cut the mustard, so moved onto the 5mm and the results were brilliant despite trash seeing. It will be my choice for faint stuff from now on Heck, I'm considering getting a 3.5mm Nagler just for this purpose

When quoting magnitudes, 'V' = visual, 'B' = blue/photographic

Scope: 12" F/4.4 dob
Time: 7.30pm - 1am
Seeing: 2/10
Transparency: 3/5
Dew: heavy.

NGC 4866
Virgo, GX, RA 12 59 27 , Dec +14 10 17 , Size= 6.3x1.3' , Mag V = 11.2

102x - Features a tight, nearly stellar core with a condensed haze in the immediate surrounds with a fainter, stubby and strongly elongated haze stretching away to the E-W, with the E side slightly more obvious. A mag 13.4 star lies at the NW edge of the core.

UGC 7841
Virgo, GX, RA 12 41 12, Dec +01 24 37, Size= 1.1x0.5' , Mag B = 14.7

Tiny and faint at 167x, perhaps with a slight increase in brightness toward the core. Slightly elongated approx N-S. Features a tiny stellar core.

NGC 4599
Virgo, GX, RA 12 40 27, Dec +01 11 47, Size= 1.7x0.8' , Mag V = 12.6

Small at 205x, with a bright elongated core orientated NW-SE with a thickness- width ratio of approx 2:3.

NGC 4666

Virgo, GX, RA 12 45 08, Dec -00 27 44, Size= 4.6x1.3' , Mag V = 10.7

A lovely spindle orientated NE-SW at 205x with a small, bright and elongated core region with fainter almost needle like extensions.

UGC 8067
Virgo, GX, RA 12 57 12, Dec -01 42 25, Size= 1.6x0.6' , Mag B = 14.1

Very faint at 205x, featureless and elongated NW-SE. Easily found along the southern border of a triangle bound by three 13-14th mag stars.

MCG-1-32-39
Virgo, GX, RA 12 42 19, Dec -05 46 31 , Size= 1x0.5' , Mag B = 14.9

MCG-1-32-38
Virgo, GX, RA 12 42 16, Dec -05 47 27 , Size= 1.1x0.7' , Mag B = 14.7

A very faint pair at 267x, seperated by by just under 2'. -38 is the brighter of the two and popped into view at 167x only after some scrutiny of the area. -39 is fainter and located 2' NE of -38, but was only spotted intermittently with much difficulty at 267x. A 13th mag and a 15th mag star located 2' E and NE of the pair served as handy reference points. This pair is located just over 300 million LY away and a tiny, 3rd object can be seen between them on DSS images, and appears to be seemingly disturbed, and with similar redshifts suggest that this group is gravitationally related.

--------

UGC 7057
GX, Virgo, RA 12 04 20, Dec +01 34 03, Size= 1.4x0.4' , Mag B = 14.8

Easily found 8' N of a mag 8 star. Faint, elongated at 267x with no features.

Polarissima Australis (NGC 2573)
Octans, GX, RA 01 41 43, Dec -89 20 04, Size= 2x0.8' , Mag V = 13.6

I've been wanting to hook this one for a while now! Finally got it. Spotted at 167x after a few minutes of scrutinising the area, but superior at 267x. Faint, and takes perserverance to spot, but quite straightforward once you pinpointed the location and give it a bit of magnification. Slightly elongated E-W and brightens slightly toward the core. A stellaring in the core was seen popping in and out of vision. NED gives a distance of 111.6 million light years.

NGC 2573A
Octans, GX, RA 23 11 39 , Dec -89 07 33, Size = 1.5x0.5' , Mag B = 14.8

Extremely faint tiny gossamer at 267x, paired up with PGC 70533, which is listed at about 0.4 mags fainter and are likely interacting as both objects appear disturbed on DSS images. Due to the listed magnitudes, it was 2573A I sighted, as its companion lies below my detection threshold as per the listed magnitudes in NED and Cartes Du Ciel (with the PGC2009 addon). This system lies approx 117 million light years away.

NGC 5426
Virgo, GX, RA 14 03 25, Dec -06 04 08, Size= 3x1.6' , Mag V = 12.1

NGC 5247
Virgo, GX, RA 14 03 26, Dec -06 01 51, Size= 2.8x2.4' , Mag V = 11.4

This is a nice pair of gravitationally locked spiral galaxies, with 5426 lying about 45 degrees to our line of sight and 5427 being face on. These objects are actually nearly 120 million light year away like the NGC 2573a system, but are far brighter and larger. 5246 lies just over 2' directly S of 5247 and at 167x it presented a diffuse elongated halo orientated N-S with slightly brightens in towards the core. NGC 5247 seemed to show a slight E-W elongation of the brighter core region with a diffuse outer halo. At 267x a stellaring seemed to blink in and out with the seeing. A mag 14 star lies just off NGC 5246's northern end.

-------

NGC 5248
Bootes, GX, RA 13 37 32, Dec +08 53 08, Size= 6.2x4.5' , Mag V = 10.3

Features an elongated core, NW-SE with a fainter outer halo. Looking at DSS shows a stubby central bar, which tells me that this is the feature I was seeing. A mag 13.7 star lies at the southern edge of the halo.


UGC 9794
Serpens, GX, RA 15 16 11, Dec +10 30 34, Size= 2.6x0.8' , Mag B = 13.5 B

Had an extremely tough time with this galaxy. I would call it the most difficult target I attempted during this session. It was easy enough to pinpoint the position, star hopping from a mag 8 star just 40' to the E, and then locating a par of ~12th mag stars between which the galaxy lies midway and just to the south of. At 267x I merely caught rare glimpses of it, I had stay on it for maybe 15-20 minutes to confirm it. DSS image shows a bizarre, disturbed object that doesn't conform to any common galaxy profile we are familiar with.


-------

So all in all a good session, I capped it off with a bottle of bubbly and a steak, loving it

another report from 25/4/11 coming soon....
Reply With Quote
  #2  
Old 04-05-2011, 09:06 PM
Paddy's Avatar
Paddy (Patrick)
Canis Minor

Paddy is offline
 
Join Date: Jun 2007
Location: Strangways, Vic
Posts: 2,208
Great to have some obs from you again Sab - it seems quite a while as you say. Very sharp observing as usual under less than ideal conditions. Some nice obs of interacting galaxies as well. Looking forward to part 2.
Reply With Quote
  #3  
Old 05-05-2011, 09:14 AM
Lismore Bloke's Avatar
Lismore Bloke (Paul)
Ad astra per aspera

Lismore Bloke is offline
 
Join Date: May 2008
Location: Lismore
Posts: 634
Hi Sab,

It seems a long time between reports. The crappy weather definitely hasn't been on our side for months. Clear nights are a bit precious.

You're dead right about higher magnification helping to reveal faint galaxies. I've gone from using the 17mm for a wide field look and the 12mm for a closer examination to using the 12mm first and then the 7mm or 5mm if seeing permits. Even if the seeing is mush, clear moments come and go, so I've had to learn patience and just persist!! The difference higher magnification makes with faint galaxies is sometimes quite amazing. Observing from suburbia means we need all the help we can get.

Cheers, Paul.
Reply With Quote
  #4  
Old 05-05-2011, 12:24 PM
pgc hunter's Avatar
pgc hunter
Registered User

pgc hunter is offline
 
Join Date: Feb 2009
Location: Renmark, SA
Posts: 2,939
Quote:
Originally Posted by Paddy View Post
Great to have some obs from you again Sab - it seems quite a while as you say. Very sharp observing as usual under less than ideal conditions. Some nice obs of interacting galaxies as well. Looking forward to part 2.
Thanks Paddy. It's funny because there hasn't been a huge lack of clear nights, just bad timing. Hopefully this burnoff shambles will come to an end already.



Quote:
Originally Posted by Lismore Bloke View Post
Hi Sab,

It seems a long time between reports. The crappy weather definitely hasn't been on our side for months. Clear nights are a bit precious.

You're dead right about higher magnification helping to reveal faint galaxies. I've gone from using the 17mm for a wide field look and the 12mm for a closer examination to using the 12mm first and then the 7mm or 5mm if seeing permits. Even if the seeing is mush, clear moments come and go, so I've had to learn patience and just persist!! The difference higher magnification makes with faint galaxies is sometimes quite amazing. Observing from suburbia means we need all the help we can get.

Cheers, Paul.
Yep, with galaxies seeing is not that critical (but hate mushy stars) so I'll use the 5mm regardless. I'd love to have the 3.7mm Ethos for these tiny faint galaxies and for tight groups. The 250-400x range seems to work very well in my experience, but in excellent seeing I won't hesitate to hit 600-700x on really tiny/faint stuff and groups. However That requires a barlow and from my obs, attempting to use barlows on these edge of vision objects seems to be detrimental. During these sessions, I also used a 13mm+barlow combo for 205x, and I decided it is not suited to faint galaxy observation, the extra glass in the light path is not what you want.

Hoping to get a 2.5mm Nagler and 3.7mm Ethos eventually! Would make a killer combo along with the 5mm.

In my scope that would be 534x, 360x and 267x respectively, now that would cover all grounds without dealing with barlows and their extra glass elements.
Reply With Quote
  #5  
Old 05-05-2011, 03:53 PM
orestis's Avatar
orestis
Registered User

orestis is offline
 
Join Date: Jun 2009
Location: southern highlands, Australia
Posts: 679
Great stuff Sab,

Your observations are always a joy to read.

Looking forward to your next report.

Cheers orestis
Reply With Quote
  #6  
Old 05-05-2011, 06:05 PM
Rob_K
Registered User

Rob_K is offline
 
Join Date: Oct 2006
Location: Bright, Vic, Australia
Posts: 2,099
Great report Mr pgc, and some interesting objects.

Cheers -
Reply With Quote
  #7  
Old 05-05-2011, 07:04 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
Well done Sab. Very interesting report. As usual you are getting fuzzies I can't even hope to get, though I have just submitted a report on NGC 4666 and noted higher power improved view of the halo.
And NGC 5248 I nabbed in April last year and clearly saw the arms with averted vision with the arm on the SE side more prominent.

Well done again especialy on NGC 2573

Malcolm
Reply With Quote
  #8  
Old 06-05-2011, 01:24 PM
pgc hunter's Avatar
pgc hunter
Registered User

pgc hunter is offline
 
Join Date: Feb 2009
Location: Renmark, SA
Posts: 2,939
Cheers Fellas. Malcolm, I use a black hood over my head, which helps greatly in observing these objects. Also make use of magnification, the difference can be quite astounding as high power darkens the background sky and improves contrast. Wish I had your skies though, seeing some proper spiral structure in anything is something I've yet to achieve

cheers
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 04:51 PM.

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