Mike JW

In complete contrast to Hickson 68, here is Hickson 50. This tiny group is also in the SHK catalogue - SHK 5. It it not far from the Owl Nebula. So why is this group so tiny? Distance is the key factor for this group. Galaxies - e, b,,a and c are between 1.677 and 1.7 billion lyrs away. Galaxy d is further out at 1.721 billion lyrs.. C is the brightest at mag 18 and E is mag 20 ( not sure I believe that). It would be interesting for you folk with 8" set ups to see what you can pick up and Tony for the wide fov to show just how small this group is - good luck. Mike

Thanks Roel - shot adds the wider fov and the PGC. Mike

Hi Tony, how intriguing - you also have a couple of other fuzz spots close to the galaxy - fleet of alien spacecraft?? Aladin view does not show the two fuzz spots. Mike

Hi Pat, If you look at the start of this thread (as with all the threads that we have set up) you will find some useful resources. Yep, go for the 200mm SCT, use an f6.3 reducer....... Have fun, Mike

I too recently took a look at Arp 27. My suggestion of the features - see below. Open to the idea that the labels are incorrect. Image processed using the latest Jocular version - definitely helps to bring out features as well as the resolution power of my Dob. Mike

That is good to know. Just found a useful article which whilst way too technical complements your explanation so currently playing with the Jocular settings - all good fun but not as exciting as getting out there observing. Mike

Thanks Tony, That has given me a better feel for what is going on but to be honest I am not sure I understand - I had better do some homework on the internet. Most the time I just move the sliders until I get what I think looks nice with no idea what I am doing or why they work. Mike

A good result. My image shows no more detail than yours but then mine is not for 18 mins. Mike

Thanks Tony - distances duly adjusted.

I too have been playing with sharpening, NR and the TNR sliders. My feeling is to not sharpen more than about a third of the way along the slider, to keep something of the soft view that would be seen visually. For the TNR I have pushed it to about half way. NR - varies all the time as to how much to use - just depends on the amount of noise, faintness of the DSO/feature. On faint DSOs/features too much sharpening/TNR and features get lost. These sliders do seem to work well on bright DSOs. Good idea to have the default value of the sliders to off. Tony - I have no imaging background so if could you explain in simple, layman's terms as to what 'median noise reduction kernal 16 and unsharp mask radius of 9' mean. All a mystery to me. Mike

Hickson 68. Recently Pat posted a view of Hickson - https://stargazerslounge.com/topic/392699-hickson-68-in-canes-venatici/ This enthused me to go and take a look at it with my current set up - so glad I did. What a glorious sight, with so much happening. The two stars with the box marking are multiple stars. NGC 5350 is a barred spiral with a ring and a starburst galaxy. 120 million lyr distance. NGC 5354 is a lenticular (SO), edge on galaxy. 132 million lyr distance. NGC 5353 is a SO, edge on galaxy with an active galaxy nucleus. 120 million lyr distance. NGC 5355 is SO or E3? 121 million lyr distance NGC 5358 is SO. 124 million lyr distance A true group. Mike

Hi Tony, So much of interest that I have been back to your post three times now just to absorb the features - housework has been abandoned!!! Last night I decided to visit Arp 18. In addition to Tony's notes - it is a grand design spiral. Arp refers to a detached segment which I presume is the bit at the top. Classified as SAB(rs)bc H11 = intermediate spiral with fairly tight arms, no ring and buzzing with star formation. It belongs to the M109 group of galaxies. VV 1504 intrigued me because it is classified as a distant pair with a bridge, indicating there is an interaction going on. Could I pick up the bridge? Aladin image for comparison. Maybe I got a hint??? Need to do a longer exposure. Mike

Morning Pat, It is a long time since I have visited this group and looking at the past image, I could do better with my current set up. Your shot has fired me up to go hunt this one out again. If you look carefully at NGC 5350 you can begin to suspect that it is a ring galaxy, which in fact it is. You may not have spotted but there is a thread for Hicksons, so if I do take a look at H 68 I will post it there and refer across to this post. Look forward to your next post. Mike

Hi Tony, thanks for adding this into the thread. It adds the wide field view to Martin and my narrower fov Mike

Arp 233, also known as UGC 5720. It also has the designation of VV 1370 (N?). Arp thought it was a galaxy with the appearance of fission. The VV classification suggests that there could be a tight group of galaxies. In colour images it is very blue, indicating starburst activity.; is this because it is actually a group but if it is just one galaxy then it must have interreacted with some other galaxy, but what is the candidate for this interaction? NED classifies it as Im Pec = dwarf galaxy that is messed up. Mike

NGC 3359 Here we again , two weeks later. Better conditions, and using 2x2 binning. Adjusted settings to remove the noise and hence the very black background to leave what I hope are true fuzz patches. Sure enough there are the two grey patches which correspond to The Cub, as per Aladin view. Mike

Arp 285 - much better conditions last night. The shot below: reduced the noise right down to leave the tidal jet/tail clearly visible but faint. If I adjust the settings differently I could not get any hint of the tidal stream between the two galaxies so I reckon it is beyond my set up and unless I started doing long exposures but I shall not go there. Mike

Hi Pat, we all have to start somewhere. You should see some of my early attempts - straight to the bin. Mike

Great to see you got the three bright spots in NGC 2856. Mike

I should know better than to try for a faint object in moonlight but 'The Cub' has intrigued me. Below is a close up of the region and yes there is some noise in the right place. I would call it 'organised noise' - it is not the normal pattern. No way I am claiming I have spotted the cub - a bit like visual observing when you have to use AV to get a hint of something (this is in category 'AV maybe or maybe not' - wishful thinking). For comparison I have included a zoomed in shot from Alaldin with the Cub marked. I need to return on moonless night. Mike

I am reasonably hopeful of being able to pick up the tidal stream between the two and the 'jet' given a decent night. Mike

Hi Tony, a superb addition to the current Arp 1 post. I have spent 10 minutes just absorbing your wide field view - such interest and beauty. I have checked back on my Arp 285 - no sign of the jet that you mention. I was geared up for tonight to look at Arp1 and Arp 285 but too windy and very unsteady skies. It works so well when we have various contributions from different size scopes/set ups with the associated comments/observations. Below is a close up of Arp 285 (from 2 years ago) and no jet from NGC 2856 but note the three bright patches in a line. The two outer ones are at the end of the bar and where the spiral arms leave the bar. Interesting article: https://faculty.etsu.edu/smithbj/research/sg/arp285/arp285.html Yet another one to revisit........ Mike

Current position of Sirius B is PA 65 degrees (not due East) and a sep of 11.27". Hope that helps. Mike

My Dob is a 15" Obsession, to which I fitted encoders and the servocat motors. It can track Ok for up to about 15 seconds and I can fine tune the tracking but unless a Dob is built to 'cabinet maker' standards, i.e it is totally orthogonal then alignment/tracking are likely to always be an issue. The Obsession is well built but it is not truly square hence tracking limitations. It seems to track better at certain altitudes. If I could have in set up permanently under a run off shed then to have it permanently placed on a high quality equatorial platform might be a better option . I have done EEVA using 5", 7", 9.25", 11" 15" (and just once on a 24") scopes. There is no ideal size aperture. It seems to me that best aperture for EEVA is somewhere in the 10 -12" range. In this range you get quicker captures and better resolution due to the aperture. However one has to accept the decreasing fov. AKB's (Tony) set up is an excellent compromise - fast, wide fov, sufficient resolution. However this sort of set up with the hyperstar is best used in an observatory. With my interest in galaxies and the small SHK/PCG groups then my size scope/set up is excellent but I immediately lose out for Abell Clusters. Also Dobs have the problems of reaching focus, hence I stick with the Ultrastar which is eyepiece size. As we know SCT scopes are so versatile, although for visual use they give such soft views due to their lack of contrast. As to your set up - probably close to being ideal. Their is no single scope that will do it all. Look forward to your next post. Mike

Hi, Great idea to post the Palomar for comparison. A good point to make re not expecting to see such a standard spiral in the Arp catalogue. A good result using your set up, especially getting a hint of the bridge. My shot below is 24 x 10sec subs, using my 15 @ f4.5, back in 2020. This was before I went over to using Jocular to process the SLL images. It would be interesting to re-visit this Arp again and process in Jocular. Mike