DaveS

So has Stargazine died then? I appreciate the difficulties and cost in finding speakers, but it would be nice if it could continue, even once a month

Seconds out, round one *ding ding*

Looking at Gain=100, everything drops disastrously, DR drops below 9 stops (Looks about 8.5) and Full Well too I think keeping Gain near 56-60 is the best bet.

That is seriously wow! How are you finding the Kepler 4040? I've heard it said that it's actually made up of four sub-sensors stuck together, and with variable characteristics between each.

Uploaded to the BAT exam.

Yep, I had been fixated on maximising DR. Maybe pushing the gain to 100 would be a good idea.

Dynamic Range for the QHY268M And Readout Noise At a Gain of 60 things look *very* interesting. Damn, I'm talking myself into doing something *Very Silly* #MontyPython

Assuming it's M106 you're after, this is what Astronomy Tools says for my QHY268M on the ODK12 Totally bonkers but might be worth a laugh or two. However, at 52MB per sub it's going to add up quickly.

My ODK rig runs at a native 0.61"/px though how much of that resolution is actually useable is a moot point.

Very nice indeed. NGC 3184 is a new one on me, but looks well worth imaging

Ha, urk yes, QHY 268, my rubbish typing.

This looks to be a job for CMOS rather than CCD. Not sure I have anything that fits the bill, though the TS apo with my QHY266M might do, but at barely 0.85"/px. Possibly my old Trius 694 on the ODK would be interesting, giving sampling at near the Rayleigh limit, but a stupidly small FoV. A QHY 368 would be a similar resolution but at £nearly £4k a bit too much.

That really is rather special.

This is from 13 subs each R,G,B using a G2v calibration from the ODK rig in my sig. 600 sec each for R&G, 1050 sec for B due to lower sensitivity. The subs were captured in Bin 1, but then binned in software before the processing. Linear Histogram stretch, DDP, then a crop and Gradient Removal. A light Unsharp Mask was applied before Colour Balance and a second Histogram Stretch with curves and a moderate Saturation Boost. This is a PNG for full detail and colour. C&C welcome as always.

Although Tunguska was the biggest attested event during the historical period, This article in Space.com suggests something a lot bigger happened in the early neolithic without killing us all.

A quick search found This article in Physics Today about the Chelyabinsk meteor. Wiki has This list of recent (Since 1900) airburst events. This Paper gives more of the physics, but it's a serious read. That's probably enough for the moment I may do another search later. Edit: This Wiki page gives a recent overview of the Tunguska event including mention of Lake Cheko, and the outlier natural gas explosion theory. But William of Occam gave a good paradigm where explanations are concerned.

Oxygen / hydrogen rich atmosphere? Er, no I don't think so. Much of the "Tunguska" sized objects kicking around the solar system are probably either barely consolidated rubble piles, perhaps with assorted ices holding them together, or else relatively fragile stony / chondritic objects. Such an object entering Earth's atmosphere would get just so far then disintegrate in an air burst leaving a shotgun pattern of small objects which would bury themselves in the permafrost. On the scale of impact events Tunguska ranks very low. Enough to have destroyed a city if it had impacted one, but still a local event. Even a well consolidated stony meteorite will break up if it isn't big enough, witness Chelyabinsk, which resulted in an air burst of around 500 kt, Tunguska was rated about 20 mt. Something like the Barringer crater needs an iron meteorite impact.

As it's a Bayer matrix binning will be somewhat more complicated. than for mono. Myself I'd leave it as is unless your processing PC is running out of storage or power. There's no need to scale to 1920 x 108-0 for display, as a lot of monitors / TVs are 3840 x 2160 nowadays.

Possibly. Don't take what I did as gospel, as there are lots of things I would do differently with hindsight. A lot can be filed under "how *NOT* to build an obsy.

Have a look at my obsy build thread from Here on, but remembering that I was making it up as I went along. I ended up putting timber beams on the inside to provide some water proofing and to give an anchor for hold-down toggles.

I used This V-Track, and These Wheels. I also added an End Stop just in case, to stop the roof coming off the end of the track. HTH

The first one has a really uneven background, with a weird sort-of rectangular negative vignetting. Plus the brighter stars are showing big halos. I frequently see very faint detail barely above the noise when processing my own images, but I would never try to bring it out in a finished image, as it's just too noisy.

My ODK 12 runs 0.61"/px with the G3 16200 camera, so may hardware bin 2x2 as I doubt I will lose much, if any, actual resolution. Just means running off another set of calibration frames. Of course, that depends on how well it bins in hardware something to test the next clear night. Next year perhaps.

I don't know, but I expect @vlaiv could give you chapter and verse .

Argh! Misread my notations, dur... This is only 13 subs stacked. Captured 15, but DSS only stacked the best 90% .