Mike JW

Martin's Arp 189 shot intrigued me at two levels; 1. actually getting hints of the extensive nature of this peculiar galaxy with just an 8" scope, 2. how does such a galaxy come about? This for me is the fun and pleasure of EEVA encompassed in  the 'observation'  of just one DSO.

When I first viewed Arp 189, I did not even think to try for the filament - before the days of Jocular. 

First up is my C11 and an ASI 174MM camera - too much noise and amp glow and just a hint of something but not really!

Next I swopped cameras and tried the Ultrastar with the C11 - whoops I forgot to orientate it the same. - better view, but nothing to write home about despite increasing the time. (annoying dust bunny as well)

The following night under similar conditions I wheeled out the 15 and slotted in the ultrastar. Hey presto I have the filament going off to the left, the extensive diffuse faint star halo going off to the right and detail of this rather attractive spiral. Also there is a mag 20 quasar and various other faint DSOs.

Thanks Martin for the challenge and inspiration for this fascinating galaxy.

Mike

I thought it was time I went chasing a few of these groups rather than the bright DSOs.  I was in Leo last night so here are three offerings.

PCG 114333+215356 - a tiny group of 5 galaxies easily lost amongst the field stars. A very lonely group but they form a 'smile'  pattern in the view.

PCG 115120+273803 is another group of five. The fov is delightful. The two obvious galaxies nearby are PGC 37109/10 and I decided to leave the bright satellite trail just to remind us all how us humans are now further wrecking the night sky.

PCG 115517+232335  resides in Abell Cluster 1413. In the wide fov, if it looks like it could be a galaxy, then it most likely is one - they are everywhere.

I think the group of five are the ones that form a V-shape in the centre of the close up. I am fairly certain that all the fuzz spots in the close up below, are galaxies.

Mike

Good that you got the pair. 

Mike

Excellent work Bill. Funny how a bright star suddenly appearing gives us such a buzz. I have a few SN on my list as well.

Mike

Superb.

Mike

Geoff

It might be worth exploring the sub time used. Greatest noise reduction occurs up to about 7 seconds so I try to use 7 seconds as my minimum time (it does depend on the scope being used and the object I am observing). Also I try to use a minimum of 20 but 30 is better in the stack to improve the picture quality. Beyond 30 there is still improvement to be had but less so.

Have fun,

Mike

Exciting that you have got underway. Amazing what you can capture with just 80mm of glass and makes much sense to play with the small scope first before firing up the 12 or 20 for EEVA.

Mike

As to which mount, I have always used a GOTO mount - you get to see so much more especially if time limited. I have had an iOptron MiniTower Pro for years and observed hundreds of doubles, much lunar sketching using this mount, as well as bright DSOs.

Mike

My scope is a GOTO; Encoders/motors. An EQ platform should work and ideally with encoders on the dob (i.e. push to ) to make life easy.

Cheers,

Mike

Don't forget double stars - much pleasure to be had from observing them. If possible I would go for a 4" refractor.

It is 1.30 am, the scope is glistening white, I am cold and I think to myself how much longer can I keep doing this (age catching up). Mag 5.7 skies, steady and transparent, M13 just visible naked eye.

Up pops NGC 4165 on the screen and there is the answer.

The reason for going to NGC 4165 in Virgo is because there is Type 11 super nova, mag 17.8 - 2021 gno is its official name, indicated in the shot below. Not more to say about this but now the interest kicks off. NGC 4165, looks spiral, dust lanes, hint of a spiral arm coming off the bottom and maybe off the top as well. Is that a ring as well? and what about the fuzz on the left hand side of 4165 - yep it is a distant galaxy. 4165 is about mag 14, lies about 105 million lyrs away and classified as SAB (r)a, H11, LINER. I should really post this in the Ring Galaxy Thread. The zoomed in shot; and sure enough I am just picking up some H11 regions

but wait, there is till so much more happening.

The big elliptical on the left is NGC 4168, a lovely E2, about 125 million lyrs away and a Seyfert 1.9. To the right is a small E3 at 822 million lyrs away - no wonder it looks small. Adding the Jocular labels reveals these three galaxies are WBL 386 - so I had better post this in the WBL thread. 

and still the interest continues.....see the shot below. Jocular has highlighted all the PGC galaxies at the mag 16/17 range. Actually some are mag 18.

Mike
 

Bill - enjoyed the read , so much to learn and find out. Thanks for posting.

Mike

Hi Bill, I too enjoyed that talk, very informative. What a great idea of yours to take another look based on the information from the talk. I last looked at ARP 220 about a year ago with the C11.

Below is the close up  to show the two galaxies of this pair and the surrounding mess of stars as they interact. Then it was thought it was just one galaxy with the gap being a dust lane. Latest radio observations show that it  is two galaxies and the two cores will merge in about 1 billion years. It is given LINER and Seyfert 1 designations.  Arp classified it as a galaxy with a loop, which shows better in my wider fov shot (not posted). It has an AGN and plenty of star formation as well. So not the most photogenic DSO as you say but so much going on.

Mike

NGC 3423 is a classic spiral - SA(s)cd. it lies about 65 million lyrs away. It has plenty of H11 regions and I enjoy its lumpy appearance due its many star forming regions. The right hand shot indicates (yellow squares) the various mag 16/17 galaxies in the fov. The one indicated by the red lines is a quasar.

This galaxy would be a fine target for a bigger scope.

Testing out the STF 7"/ASI 174 MM camera with this shot - plenty of targets for this size scope.

Mike

Last night (05/04/21) I was testing the ASI 174MM/Jocular using my STF 7" scope.

SN type 1 - 2021 fco is to be found in Leo - UGC 5801 and is faint at mag 17.8. Quite a challenge for a small scope. I find that the high noise/amp glow of this camera does not lend itself to a black background but the grey background as per the shot below works fine.

Mike

Hi, Fascinating write up and lovely to see this cluster which is so low down for us in GB. I always enjoy multiple stars, especially when tracking them down visually. I cannot find Tau CMa in the Washington Double Star catalogue.

Mike

Ok, it is another shot of Vesta. I did this with the STF 7" and at the same time trying out a ASI 174MM camera.  I think Bill's shot with the Diffraction spikes look better.

M3 in CVn made for a nice diversion from chasing galaxies on 30/3/21. Its age is thought to be about 11.8 billion years and is classified in group 6 (mild concentration of stars towards the centre), contains around 500,000 stars, and lies about 33,900 lyrs from us, it is 180 to 200 lyrs across.. Its central core is just 11 light years across. The brightest stars are about mag 12.7. As it orbits the Milky Way, it can be as far out as 66,000 lyrs from the galaxy centre and get as close as 22,000 lyrs at which point some of the outer stars maybe stripped away. 268 variable stars have been located in this cluster.

Hi Martin,

You did well picking up as much detail as you did. I was disappointed with my shot not to get a hint of the spiral structure. See Aladin screen shot below. I agree that it looks very much like a face on spiral.

I fancy another thread for overlapping galaxies!!! - some fine examples in your reference.

Mike

VV 267, UGC 6073, (Arp 198).  In my pursuit of the VV galaxies, I called up VV 267 in Leo and chuckled to myself as the image appeared - I immediately thought of a vegetable! - "The Cosmic Carrot"

This pair (PK, pair in contact) lie about 431 million lyrs away.

Mike

To illustrate Martin's comments. The images below are all a stack of 6 x 2sec subs, using an ultrastar and a C11 and obviously a much smaller fov. The final image is the best I could do using a linear stretch without over doing the trapezium.  I probably should have used 1 sec subs. In a zoomed in version of the image below I can just make out component E (not posted).

Mike

Hi, I fear I am missing something here - I cannot see the 4 stars of the Trapezium. I can detect where they should be.  Have they been lost in the posting of the image?

Cheers,

Mike

IC 1747 in Cas is a small PN and easily missed in a crowded star field. (centre of the wide shot). Some folk call it the Holepunch Nebula - beats me as to why this name!.  The shot is with my 7" scope  and would be of more interest in colour , bigger scope and probably a small pixel camera.

Close up indicates it may well be bi-polar.

Mike

Hi, Only the other day I was thinking that you had not posted anything and was wondering if your were OK. M79 is always tricky for us in GB due to it always being low down in the murk. Visually in a big Dob it lacked the sparkle of higher up globular clusters. I have never even bothered to point the scope/camera at it, so great to have your post with such an interesting read as well.

HR 1771 - I always like to see doubles and multiples ( a once favourite astro pursuit of mine with a high contrast scope).

Mike

Hi Martin,

I have had a long break from sketching - not enough time to pursue all my astro interests and others. I so enjoy my EEVA explorations. Tonight I did view a lovely moon and thought maybe I should get the sketching materials out again.

All the best

Mike