gorann

Depends on your scope and camera. My gut feeling is that for an object like this with a RASA 8 at f/2 and the very sensitive ASI2600MC then 4 min will be quite enough to capture everything there is for it to capture. With an f/5 scope with a CCD then maybe 30 min would be needed.

Thanks Peter! I am on to it if I get enough clear skies. Great targets for the RASA since the Milky Way is now largely below the horizon.

Thanks Ian! No deep thoughts about the level of exposure really. In this case I thought 4 min was appropriate since there were no very bright objects in the field that would have been blown out. I do not think it matters too much with this camera since it has virtually no read noise. Longer exposures means less to store and stack but shorter exposures means you lose less if you have occational clouds around. So, 4 min seemed as a good middleground. I expect anything between 2 and 10 min would have given the same end result.

Thanks a lot Dave!

Thanks Wim! Catching a lot of galaxies is another advantage of the RASA wide field!

Thanks Gerry!

Thanks Wim, I am glad I did not disappoint😉

Thanks a lot Kinch!

This faint nebula is made up of Integrated Flux Nebula (IFN), which according to Steve Mandel-Wilson is dust lit up by by the energy from the integrated flux of all the stars in the Milky Way. For being IFN, I get the impression that this nebula is relatively bright, but it certainly took quite a bit of stretching to bring out. Numerous galaxies can be seen hiding behind the dust. Captured 4th and 5th of March with the RASA 8 and ASI2600MC (gain 100) without filter. 85 x 4 min, so 5.7 hours. Thank's @wimvb for suggesting this cool target! EDIT: Added the annotated image provided by Wim.

I should really not aim this close to the horizon under a nearly full moon but the NBX Oiii Ha filter made a rather good job, but I could only use 2 - 3 hours of the subs each night before the bright horizon started to fade out the signal. Cederblad 51 is stated to be a reflection nebula but I wonder if it also emits Oiii since the NBX filter should not pick up much blue reflection nebulosity. Collected 27-28 Feb with the RASA 8 and ASI2600MC and NBX filter (Ha+Oiii). 34 x 500s, so totally 4.7 hours. Stacked in PI and processed in PS and PI. EDIT: added a annotated image from Astrobin showing the Barnards in there

Thanks Poogle! The spider is the one in the center shooting out a red harpoon down against the "fly" at the bottom left, supposedly..... I assume you can see the two small tadpoles (grodyngel) in IC410 if you zoom in. You can see quite a few RASA images on my Astrobin page, link below.

Here I have combined RASA 8 data from the other night on the tadpoles (IC410), spider (IC417) and fly nebula (NGC1931) with RASA 8 data on the tadpoles from November 2020. All under a moon lit sky so I used the NBX filter. Clearly there is a lot of Ha nebulosity in this region. The recent data (64 x 5 min) was collected 26-27 Feb and mixed with 27 Nov data (83 x 2 min). All with the RASA8 and ASI2600MC and IDAS NBX (Oiii Ha) filter. So totally 8.1 hours stacked in PI and processed in PS and PI. By the way I never understood how NGC1931 could be seen as a fly; maybe it has to do with my love for insects. The annotation is from Astrobin.

I would stop searching and go for the excellent Esprit 100 with the dedicated flattener, except it looks like neither FLO nor TS have them in stock right now.......

Thanks a lot John!

Thanks Paul! My average SQM is similar to yours. The best I have had is 21.6 but when this image was taken it was probably around 20.5 due to the reflective snow cover brightening the sky. Snow is gone now but the moon is back 🥴

The field of view of my image is about 7 x 5 ° if I got it right.

Thanks a lot! I think dark nebulae may be a challenge visually, but the very best of luck! There are some bright spots there including IC2087.

Thanks a lot! Yes, there is an interesting shine there behind the dark dust.

Thanks a lot! If you just can get the distance to the senor and tilt right it is a great set up. I often do have to work quite a bit in processing on star shapes in the cornes, but then using and APS-C sensor is outside the promised range from Celestron. It seems from my experience and others that the factory collination works right out of the box and holds, so in that respect it is just like a refractor.

Thanks a lot guys, you are all too kind!

This is a two panel mosaic where I used one of the panels from my recent mosaic, containing Barnard 14 (with IC2087), and added a new panel (the bottom half of the image) dominated by Barnard 18. These nebulae belong to the Taurus Molecular Cloud. 12 hours of total integration time with the RASA 8 at f/2 brings out quite a lot of light and colour even in dark nebulosity. Imaged 10 - 14 Feb with the RASA 8 and ASI2600MC (gain 100) without filter. 180 x 4 min. Stacked in PI and processed in PS and PI. I also post an annotatded low-resolution version grabbed from Astrobin. From Wikipedia: The Taurus Molecular Cloud is a molecular cloud in the constellations Taurus and Auriga. This cloud hosts a stellar nursery containing hundreds of newly formed stars. The Taurus Molecular Cloud is only 140 pc (430 ly) away from earth, making it the nearest large star formation region. It also reveals characteristics that make it ideal for detailed physical studies. It has been important in star formation studies at all wavelengths.

Actually, I just ordered a second JTD saddle for my upcoming double RASA 8 rig. Still, I wonder why this seems to be the only adjustable double-rig saddle made.

I have my Esprit 100 on a JTD saddle next to my Esprit 150 - no problem.

Thanks a lot Paul! Yes this f/2 scope really brings out the faint stuff. Dark nebulae are no longer dark and actually are quite colourfull.

Thanks a lot Dave!😆