gorann

Thanks a lot Martin, much appreciated! Yes, I am back and working hard and late to collect data for a fourth image of the season😁. It would have been the fifth if not a nap unintendently on Sunday turned into a full night sleep🥴

Thanks a lot Ian! My lines are somewhat arbitrary, and usually I go for one object per night, so on long dark nights in the winter I may get up to 20 hours or more (since I have a dual rig). For this one the night only gave me 2 x 3 = 6 hours. For relatively bright objects like this one I found that 5-7 hours or so is enough and I would probably need more than the double to see a very small difference in S/R. For very faint stuff like IFN and SNRs I usually aim for at least 10 hours. It is all at f/2 of course so I soon get very deep and 10 hours of RASA data correspond to several days at f/7

Hi Alan I did what you asked for last night. I went for Arcturus, the brightest star in the northern hemisphere. Here are three single 1 second frames at gain 100 with an ASI2600MC. So, left edge, center and right edge of the field. As you see there is none of the flares you see, so it is most likely a problem with the current RASA batch. Cheers, Göran

Thanks Alan, so do you say I should go for 60 s subs or less? In the winter I can get 20 hours with my dual rig in a night so then I would spend days stacking 1200 subs (not to mention the harddrive space needed). Or should I run it at gain 0? I do not feel I have much problem with the stars and I do have to stretch the data a lot sometimes to get to the faintest stuff. But I never made any calculations like you have. CS, Göran

Thanks a lot Peter, much appreciated! Being a natural scientist (although not in astronomy) I am set to go for the relatively unknowns, so sometimes picking out the objects takes as much time as imaging them.

Really nice Wim with these two galaxy groups in one frame and I am not bothered by any tilt as I cannot see it at the image scale you present it (and I have a 44" monitor).

Thanks a lot Dan! I like chasing those less well known objects out there.

Finally a clear night last Wednesday that had enough astrodarkness to be worthwhile! I aimed my dual RASA8-rig at the rather seldom imaged LBN 534 in the constellation of Andromeda. It includes the blue reflection nebula vdB 158. There is also a small planetary nebula near i (PK110-12.1). I used starless processing to bring out as much nebulosity as the data allowed, and remarkably the Star XTerminator filter did recognize the planetary nebula and left it in while removing virtually all stars. Apparently, in her catalogue Beverly Turner Lynds missed the patch of brightish nebulosity to the left of LDN 534 (but then she did not have a RASA😁) so it may have no designation. I include the annotated image from Astrobin. Two RASA8 with ASI2600MC (no filter) on a Mesu 200 mount. 124 x 3 minutes, so 6.2 hours. Processed in PS and PI. Cheers, Göran

For the first time it happened to me. I just woke up and it is 4 am. At 8 pm I opened up the obsy roof to let the scopes temperature equilibrate and thought I needed a short power nap. I had not activated the snooze function on my smart phone and the wife, which normally would have got me up, is visiting her mother. The sky is clear and looks fantastic now in the early dawn, and I can hear a male roe deer barking........ Has this happened to anyone else here? Cheers, Göran

Mesu 200🤗, friction drive that can handle 100kg and no maintenance, no backlash, but Lucas only makes about 40 a year so put yourself in line asap.

A bit too late - I had a clear sky last night and was shooting away with my dual RASA-rig, but now clouds have moved in. I will try to remember your request next time it clears😉

Finally, after a long bright summer I am exposing again. Got the dual RASA8 rig up an running in Obsy 1 and aiming at the rather obscure nebula LBN534 in Andromeda. I spent much of the summer adding an extension with a pier to Obsy 2. Soon a dual Esprit 150 rig on the Mesu 200 I bought from @ollypenricewill move in there.

Physical print copies are nice to have and read but when it comes to images they (un)fortunately look much better on my computer screen

Thanks! I just wish they had not put the dark square with the text over the Iris. I was quite disappointed but I guess that was the doing of some layout person at the publisher. This is what my image of the month really looks like (sorry for hijacking the thread for posting my images🥴) Cheers, Göran

As always on the net you need to filter what you read and find out who to trust - takes some experience. I know that CN is not like SGL😉

I trust it will be a move to a dark site! Fortunately I have a farm with space for more than one obsy (I am just finishing my 4th) so my 14" Meade has its own obsy and most nights its stays closed unless there is really great seeing. On average-seeing nights I will use my shorter FL scopes (RASA8 or Esprit 150) in the other obsies. So, unless you find a site with really steady skies I think that only having a 2-3 m FL scope could be a bit frustrating. My dual RASA8-rig (400 mm FL) does not care about seeing at all. Only clouds can stop it. I am impressed by your Swedish - I hope it was not just google translator😄

I fully agree. Sky at Night is also only giving out four or five stars to everything they "test", so it is the net, including SGL and CN, that you need to turn to for objective evaluations.

This is what the same target looks like after 9 hours at f/2 with a RASA8 and ASI2600MC under my Bortle 2 sky. Not that different, so one may wonder....... https://www.astrobin.com/ick5pe/B/ One trick that really helps bringing out faint signals is to do most of the stretching on a starless version before bringing the stars back.

It is not impossible. As I said I got the August image of the month in AN and it is from my backyard in Sweden😉.

I used to subscribe to Sky at Night but now it is Astronomy Now that I find in my mailbox - a clear improvement! A bit more in depth. Some may have noticed that the gallery fills up more and more by images processed from one particular commercial data provider. But I should not complain since I have the image of the month in the last issue😄

I stumbled on this thread and may be a bit late. As @ollypenrice pointed out don't rule out a 12 or 14" SCT, especially if you get an Obsy v2 that could accommodate one. I would suggest the Meade ACFs with a proper focuser added to the back. Then you can have the primary permanently locked and no mirror movement to worry about. The Meade ACF (in contrast to EdgeHD) are very forgiving about sensor distance since they achieve the flat image with the corrector plate and mirror rather than a set of correcting lenses (Edge HD) that demand a rather short and precise back focus. And as also pointed out by Olly, it is a sealed tube so no worries about dust on the mirrors like in RCs. As you see in my signature I have both types of SCTs, and the EdgeHDs are also lovely scopes, and have the advantage of lower weights but in a permanent obsy that is not an issue. Both brands can at least fill a full frame (24x36) sensor with photons. Here is an example of what my old 14" Meade can achieve: https://www.astrobin.com/kqe06r/C/

It strikes me that when I have seen advertisement for domes, only the size (diameter) seems to be an option, not the width of the shutter. Apparently the odd ones like you and me who like dual or triple rigs are not taken into consideration.

When I visited Lucas Mesu in July I asked him about how he knows it can handle 100 kg and the answer was simple: he had tested it with 100 kg and it was fine. But he said it behaves slightly differently with a lot of weight - pure physics of the momentum of a big load.

Having only primitive DIY slide-off roof obsies where only the sky is the limit (or rather trees and obsy walls), I never had such luxury issues, but the very best of luck Steve😁

Very nice as it is and a the beginning of something outstanding! And I never realized that the Crescent was actually slightly larger than the moon😉