gorann

PS. Do you need a dew heater? Those of us using RASA8 get enough heat from the camera inside the dew shield to keep dew or frost away (works for me even at -18°C)

That was a new one I had not heard of. Great that you could fix it!

Getting better and better Olly! Not sure why you think "back lit" is a problem. My feeling is that they were darker in the old days just because we did not have such sensitive scopes and cameras. Obviously there are stars behind them that will illuminate the dust. Let's leave the dark ages and liberate the nebulosity!

PS. That thing down at the bottom left is PK204+04.1: https://pbase.com/skybox/image/169014009

I guess I need to collect more data one day... Thanks and Yes, partly depending on the screen setting, it was a bit too red so here is a less saturated version

Good idea Adam, so here is the image with the red channel deleted (Oiii is collected by both green and blue pixels in the OSC). Not sure it finally settles the question about an Oiii bubble. Interestingly I get the impression that a big chunk of dark nebulosity is covering part of the possible bubble.

Thanks a lot! Yes, quite a mix of bright and very faint targets, so a fun challenge to process.

Over the last weeks I have aimed at different parts of the Monoceros complex with focus on some more or less unknown Oiii structures using IDAS NBZ filters (dualband Ha+Oiii) with my tripple-rig with two RASA8 and one Samyang 135. Here is a mix of those data, totally 23 hours at f/2. In addition to the well-knowns It contains the Strottner-Dreschsler 155 object (I posted the RASA image yesterday) och the rarely imaged SNR G206.9+2.3 down to the right. Now I think I also see a huge bluish bubble in the top left quadrant, maybe even covering the Cone Nebula. Is that just my imagination, and if not has anyone seen it before? Cheers, Göran

Thanks Olly! Is the RASA rig broke?

I could have been lucky but it is worth a try.

Thanks Wim! What I know is that my Samyang 135 f/2 would not have pulled this off, so at least "aperture rules" is not a myth😉

A few days ago @ollypenrice posted a very nice and dusty RASA image of the Cone nebula and Dreyer's nebula (IC447), and about the same time Marcel Drechsler and Xavier Strottner posted their latest discovery on Astrobin: Strottner-Drechsler 155 (https://www.astrobin.com/vy1kma/). I realized that all three objects would fit into the field of view of my RASAs so when the sky cleared and the moon was rather low last night I thought I would check if my dual-RASA8 rig could detect it S-D 155 and include the Cone and Dreyer's. My SQM is usually above 21 but snow on the ground lightened up the sky so the meter showed 20.5. The object was also very low so I could only collect 2 x 2.25 hours before it fell below the horizon. S-D 155 is the blue object near the lower right corner. With only 4.5 hours and a focal length of 400 mm it is of course not as outstanding in detail as it is in the 80 hours 1200 mm image of Drechsler and Strottner, but there it is, and I think it is nice to see it in a wider context. Caught with RASA8 and ASI2600MC and IDAS NBZ filter. 54 x 5 min. Processed in PI and PS, including all the new XTerminators.

It happened to one of my RASA8 about a year ago. I realized I needed four hands to solve the problem so I got my wife to help me to tighten a rubber band from a rubber strap wrench (like this one https://www.maxclawtools.com/rubber-strap-wrench-sw-530.html) around the lens group ring and hold it fast so I could loosen the camera adapter ring and camera. I then tightened the ring on the lens group hard (so it would not happen again). A star test told me that nothing bad had happened so no collimation needed. I have since then added a tiny amount of grease to the camera adapter ring so it will not jam.

Yes, an outstanding image Martin and I am amazed what you now can do to old data! Thanks Russell! It almost feels like cheating but it is as @ollypenrice says just the relief of working on nebulosity without worrying about the stars. And everyone are doing it so it is just how processing will be done from here on.

That dust gives such a great 3D feeling to the image, and perhaps even more so in the second image. Some structures really look closer to us than others (and presumably they are). Indeed, some googling tells me that the Cone is at 2700 ly and IC443 is at 2000 ly, which fits with the perspective of the image.

Well, apparently at least some do as seen in the post by @Spaceship above. I can see it in one of the pictures.

Beautiful image of a beautiful area Olly! I really like the dust not seen in most images of this area. Did you use a layer of Equalize to bring a bit extra dust out? Any filters used?

Great image Alan with lovely detail! Have you used Blur XTerminator on it? If not, it may not only bring out even more detail but also fix the minor star issues that @ollypenrice noted.

I have three ASI2600MC and use no dark or bias calibration frames (I initially made a dark library but using a master dark made no noticeable difference and I have repeatedly heard the same from others). And I do not dither. Still I rarely see a hot pixel. I think it has to do with the Image integration routine I use in Pixinsight (see below). In the rare case of a some hot pixels they are easily removed by the Dust & Scratches filter in PS (using a low setting that does not affect stars).

Looks really great and very inspirational Dave! Reminds me that it is high time give my Iris data the same treatment.

Thanks Olly! It shows that there are still a few rarely imaged gems out there. I am sure it would be even more ethereal on a moonless night with a more steady sky. My RSM was around 1.5" that night, while it is usually between 0.5 and 1.0".

Thanks Olly! I did not know about it either until I though I saw something there i a recent wide field image someone posted on Astrobin. A bit of research revealed that a few people had actually imaged it. So it bacame a RASA target for me and this image is the joint effort of the RASAs and the piggybacking Samyang 135. I could actually see a faint trace of it also in the 4.25 hours I got with the Samyang. Here is the RASA image of the SNR:

Thanks Rodd! Read my post and you find a link to that object😉

The Monoceros SNR is the enormous circle of mainly Ha emission between the Rosette Nebula and the Cone Nebula. Above it is the much smaller (but still relatively large) and very faint blue Oiii-emitting SNR only named G206.9+2.3. This is what my Samyang 135 caught piggybacking on my dual-RASA rig over two recent nights. I have added about 50% RASA data to the Rosette and the blue SNR. For more info on the blue SNR see https://www.astrobin.com/8wuzok/ Materials and methods: 51 x 5 min with Samyang 135 and an Omegon veTEC571C with IDAS NBZ filter, and 102 x 5 min with RASA8 with ASI2600MC and NBZ or Baader high-speed Oiii filter. So totally about 16.5 hours. Processed in PI and PS including all the XTerminators. Cheers, Göran

EGB 6 is a very faint planetary nebula in Leo. It was catalogued by Glenn Ellis, Earl Grayson and Howard Bond in 1984 after looking through prints from the Palomar Sky Survey. It is big (8 light years wide) and relatively close (2100 ly), so it is old (probably 50 000 years) and therefore so very dim. Even @Petergoodhew, who of course have imaged it, calls it extremely faint. I imaged it under 50 - 70% moon, so not ideal, but the RASA is a photon bucket. Dual-RASA8 rig with ASI2600MC. IDAS NBZ filter on one and Baader high-speed Oiii on the other. 102 x 5 min, so totally 8.5 hours. Processed in PI and PS including the XTerminators. Cheers, Göran