gorann

Thanks a lot Simmo!

Thanks a lot an Yes Olly, I was fighting with the red that appeared to be leaking through all over by its own. The data did this more or less by its own and I decided to leave it like this. I noticed that in LBN 531 what is usually seen as dark patches are now quite red (except in its head for some reason). Obviously there is a red signal there but maybe it needs to be suppressed and I am too weak to tell it off😅. Cheers, Göran

Thanks a lot Peter, much appreciated as allways!

Third image(s) of the season While aiming at this area in Vulpecula I had my dual-RASA8 rig acquiring RGB (no filter) on one scope and HaOiii (NBZ filter) on the other and then processing it with and without stars (using Star XTerminator). The differences were striking. Image A shows what it looks like in RGB, with an overwhelming golden star field and with the HA emitting nebulae quite obscured. Image B shows the starless version of the HaOiii image taken with the IDAS NBZ filter, revealing that behind the stars is a thick mesh of dark nebulosity apparently covering what could be a wide reaching area of Ha emitting nebulae. In Image C, I combined 75% of the HaOiii data with 25% of the RGB data and added the RGB stars at a suppressed level to still show what was lurking behind. The patch of blue nebulosity at the very left edge with a striking blue star in the centre (if you zoom in) is the planetary nebula LAN 21 I find it quite striking how different celestial objects look when aquired and processed in different ways. So, two RASA8 with ASI2600MC without or with an IDAS NBZ filter, on a Mesu 200 mount. 61 x 5 min with the NBZ filter and 95 x 3 min without filter, so totally about 10 hours. Processed in PI and PS. Very happy for comments of course Cheers, Göran Here pure RGB - overwhelmed by stars.... Here a starless HaOiii image - a lot of dark nebulosity and dust covering the Ha emitting nebulosity And my final version of it. HaOiiiRGB. Not an easy task to process and many choices to make. And an annotated image so you know what you are looking at

Thanks a lot Bryan, Onikkinen and Carole for you kind words! In this image I decided to hold down the dust a bit to allowe the main features stand out. There is certainly a lot of dust in this area and a lot of dust in the data.

Thanks a lot Steve! To me the head of the top one looks a bit like a seagull but not sure what to make about the rest of its body😅. The bottom one looks like it has been decapitated and is on its way down.... I had missed that there is a new SGL challenge that may be relevant to me, and maybe I can come up with something else from Ceph or Cass.

Resizing is simple in PS. I do it kind of manually by measuring the distance between the same two points (could be stars or anything that you see in both images) in the two images (using the ruler tool in PS). Dividing one length with the other gives you the factor you can use to resize one of the images so they will be on the same pixel scale and can be aligned.

Thanks a lot Dave! Much appreciated 🙂

Second light of the season with the dual-RASA rig I aimed at these odd creatures in Cepheus that were among those recently parading in the magnificent RASA mosaic presented by @ollypenrice. I got 94 x 3 min, and to LBN 531 to the left I could add another 5 hours of data from two years ago. LBN 531 is quite often imaged and spectacular enough to be given at least three annotations: LBN 531, VdB 152 and Cederblad 201. The image also contains the planetary nebula PK111+11.1 and a streak of Ha nebulosity belonging to a super-nova remnant. The RASA8-ASI2600MC combo is amazingly good at picking up Ha even without a filter. So, RASA8 with ASI2600MC without filter on a Mesu 200. 203 x 3 minutes, so totally a bit over 10 hours. Processed in PI and PS using starless processing (Star XTerminator) on the nebulosity. Cheers, Göran

Yes, skip the L-extreme, and you will find that is is actually a very bright nebula and will look good in RGB even after only 4 hours. Will be a perfect catch for your Esprit 150. CS, Göran

That is a great image and a excellent choise of sky for a mosaic Olly! So far I have only been picking pieces of it with my RASAs. Indeed I aimed at the two creatures at the bottom two nights ago. So it is great to see it all together, although it makes me wonder what is it outside the frame to right of them that make them all rush away😱. Yes, this scope - camera combo is surprisingly good at picking up Ha without any filter.

To me it looks like a military version of a Mesu 200, and the image with them all lined up looks quite threatening😆

The one with mask looks rather good so I suggest you just make the best out of the RASA you have until you get an replacement. Here are the raw fit files. Cheers, Göran 2022-08-29-2022_1-CapObj_0001.FIT 2022-08-29-2023_9-CapObj_0001.FIT 2022-08-29-2024_9-CapObj_0001.FIT

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.