Mike JW

Here is my image from last night (1/3/20). PGC 23057 above it. mag 15.7 spiral (hint of being a spiral in my shot but more obvious in yours). Mike

Morning Martin, I took up your challenge last night. Transparency was excellent but the moon was bright. I too failed to pick up the mag 20 quasar but fun trying. Mag 20 I suspect is beyond the set up on a typical GB night but might be doable on the occasional excellent night. I might try the 15/camera. I wonder if the quasar is lost behind the fuzz of the galaxy plume. Mike

I remember this freaky galaxy from my visit last year. Pity I lost the image. Thanks for the info which I have summarised in my own Arp document for when I get to revisit this chaotic scene. I have started reading the articles - way beyond my knowledge but of interest. Ring galaxies are fascinating. Mike

Nice one. Always amazed by what can achieved with just 6 inch of aperture. Mike

Thanks Bill. A while back I downloaded Jocular but was at a total loss on how to install it (Windows). Martin did try to help but suggested I contact you as you use windows. I will message you at some point for help. Mike

Hi Bill, thanks for the encouragement. Taurus is complete but not posted. Next up is Gemini. Mike

I enjoy sharing and comparing our observations. Thanks Bill and Martin.

I looked at Aladdin images and shows the curving tail. On another high resolution image it clearly showed two (foreground?) stars. Your shot gets both the faint galaxies above. I only got the brighter (bigger) one. Mike

Hi Rob, It took a while to produce the document. Glad you like it. I have pondered at doing this for all the constellations - weeks of work!!!!!! I have all the list made up for each constellation but doing the EAA images is a monster project. Mike

Arp 165 - NGC 2418 is a larger peculiar elliptical galaxy which Arp classified under galaxies with diffuse elements (what ever that means). It lies about 240 million lyrs away. It has a hint of a "jet" but professional images show the presence of two stars at this point. The galaxy seems to have suffered some sort of disruption but there are not any nearby candidates. There is a galaxy just above it but that is likely to be distant.

Impressed Bill with your Comet image. I never get anything of that quality. Do I need to go down the Jocular route? Martin/Bill - I too visited Arp 165 recently so I will set another post going. Mike

Thanks Martin. I am fascinated by just how much we can see using the EAA technique. I agree that the VV galaxies give the Arps a good run for their money. Maybe one day i will explore the Abell groups. Mike

I have been working my way through the EAA galaxy targets in Orion. For my own records and reference I have created a document. Attached. Mike EAA targets in Orion.docx

Martin, wonderful contrast in galaxy types. It makes for an interesting session when different types are observed. In some of my recent sessions I have tried to do a mix as well. Dr Arp classified Arp 6 as a spiral with low surface brightness. Some folk have suggested that its shape is a result of a merger. The remnant being the obvious bright blob - top right. A merger would explain the bright knots of star formation. Great idea to do the colour to show these hot blue regions. Thanks too for the references. I do like ultra thin galaxies - visually and EAA. I was out there last night but way behind writing up/posting. Mike

Hi Martin, At the risk of opening up the debate about what is "live" EAA, the advantage of using the 15" Dob is the speed of the view. Often in under 10 seconds. The stacking is really just to try to reduce the noise. Interestingly so with such large aperture it is better to use the "median" stacking rather than the "sum" for brighter DSOs. The advantage of my second tour of the Arps is that I am spending more time teasing out detail/more reading up. Looking forward to your next post. I find the Pretty Deep Maps incredibly useful especially for the SHK groups. I also fancy a peak at the Berkeleys with the 15 operating at f2.25.....there is no end to the targets!! Mike

After my trip into Ursa Major (see previous post) I wandered over the border in to CVn. I have chosen three highlights from a very productive 2 hour session. Arp 269 – is an interacting galaxy pair that have had a cosmic collision, actually a near miss and are now moving apart. The result is a galactic carve up. The link between them is about 25,000 lyrs long and made up of hot gas and star forming regions (knots). NGC 4490 is known as the Cocoon Galaxy and a barred galaxy (SB pec). The smaller companion NGC 4485 is classified as IBm pec – an irregular barred galaxy – simply put, it is well and truly wrecked by the collision. I am pleased to have picked up the knots in 4490 and it appears that the left side as viewed has suffered the most disturbance, the side nearest the passing 4485. The bar can be seen in 4490. Arp 281 is an interacting galaxy pair. The small NGC 4627 (17,000 lyrs across) is being pulled into the big 4631 (known as the Whale Galaxy, 116,000 lyrs across). NGC 4631 is an edge on barred spiral, with 400 or so billion stars in it. NGC 4627 and 4656 are thought to be part of the group. SHK 71 I am a sucker for these very faint galaxy groups and this is where the 15" Dob and camera can really do the business in a short space of time. Obvious star drift on this shot but I was so excited to pick up this group that it does not bother me. A close look at the inset reveals a probable tally of 13, with some hot pixels and noise. In the same session I did two other SHK groups and various other Arps - still to write them up. Shots have been cleaned up a bit in Photoshop. Mike

Very transparent skies last night. I wanted to find the comet and noting it was near to M97 and M108, I took a peak at these well known objects. Currently this comet is in the region of mag 14 and has been getting brighter. M97 - needs no comment except to note I picked up the nearby PGC galaxy, lurking near a star. M108 - enjoyed picking up the detail. It does not have the typical prominent central bulge of a barred spiral. It certainly is a very dusty galaxy. A tricky time doing these shots in windy conditions. Had to start again several times and drop the last stack often. I also kept the time to just 2 sec to help beat the gusts. If I heard a gust coming I would stop the stack and wait until it had gone through and then re-start the stack. Mike

IC 2312 lurks some 1.12 billion lyrs away. It is the brightest grey fuzz (see the inset for a closer look) at mag 15 and is thought to be 100,000 lyrs across. Below it is a star; not a galaxy. Above it is its companion (PGC 1561719) at mag 16 or fainter. I could not find data for it. Possibly it has nothing to do with IC 2312. - line of sight and no interaction? Arp 167 (NGC 2672/73) is pair of interacting galaxies with diffuse counter tails according to Arp's classification. Professional images show a very tight counter plume from the companion. They are both elliptical galaxies and lie about 167 million lyrs away. Arp 89 (NGC 2648) is a spiral with a large high surface brightness companion. They are about 107 million lyrs away and inhabit an empty region - no other galaxies nearby. The main galaxy does not appear to be distorted by the interaction, presumably because it is so much larger than the companion. Arp 243 (NGC 2623) is the result of the merger of two or maybe three galaxies. The merger is thought to be almost complete. Arp classified the pair as having the appearance of fission. A very enjoyable outing, finding these guys in difficult, windy conditions. Mike

Hi Rob, Good idea to recover the images from SGL. I enjoy doubles and will sometimes do doubles at the start of a session then switch to EAA and then finish on doubles/clusters. I can supply lists of Cambridge 2nd Edition Doubles for all the northern constellations. These are true doubles/multiples. In excel spreadsheet form. Just ask if you would like some or all of the lists. Anyone reading this - just ask - happy to share. Mike

In the early hours I manged this shot, despite the annoying wind (had to wait for a lull and then go for it. Desperate to do something in this terrible wet and windy spell. The Arp pairing are the obvious spiral (Hickson 73a) -NGC 5829 and its line of sight companion IC4526 (Hickson 73b). NGC 5829 is 265 million lyrs away and its companion is 620 million lyrs away. Well worth looking at professional images of the pair. I just started to get a hint of the star forming regions in NGC 5829.

Hi Martin, I have just managed to grab an hour before cloud arrived, so I pointed the C11 at NGC 2017. A lovely sight. It has been awhile since I looked at it visually. Hint of colour seen. I then put the camera in and took a shot of NGC 2017 - not posting it - it lacks the sparkle your image does. Next I took a look at Arp 123. I had to use 3 sec subs because of the wind. Also looking through thin cloud at times. No sign of the thin line. Mike

Hi Martin, Arp images well and truly lost. A long story and yes they may well lurk somewhere but way out of my knowledge to see if they still exist. However as you say a great excuse to do it all over again, this time with much more camera experience. I shall of course pick them up again as I peruse the VV galaxies. Mike

Hi Mike, EAA is about getting an image reasonably quickly, (the idea of being "live") - there is much debate as to what might be reasonably quick. To get an image as quick as possible: Increase the aperture, lower the focal length and use very sensitive camera (effectively pixel size). Colour cameras are not as sensitive as mono cameras. Smaller pixels are less sensitive compared to bigger pixels. The altair camera you are considering has small pixels and is colour and combined with the size scope you plan to use will limit what you will see. I have limited understanding of software and my experiences of using the associated Altair software was nightmare to use. I tried the other suggested software - Sharpcap. I got on slightly better with Sharpcap. Both lack the ease of use compared to Starlight Live software. However the Starlight Software can only be used with Starlight Express cameras. I use the Starlight Express Ultrastar (mono), other folk use the Lodestar (mono). Folk who have far more understanding/knowledge than myself use a variety of other cameras and software. For a while I used a 5" refractor and a lodestar (mono) and got some very pleasing results. Vlaiv is quite right to suggest a 1-2 degree fov for general viewing. I use considerably less fov as I am interested in distant galaxies but my narrow fov is useless for extended objects or large galaxies. Mike

Hi Martin, You did well to get the thin line for Arp 123. I wish I had your knowledge to do the colour thing - a whole new dimension. I cannot compare to mine because I have had a computer disaster - all 330 of my Arp images on the laptop and the two back up copies held elsewhere have all been corrupted and lost!!!!!!!!!!! Gutted to say the least. What is a log stretch? and x/(x+c) stretch. Mike

Nice one - made me smile. Must be a name for this approach? What about converting our sketches to playing card size and then using them for some sort of game?