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Thats an interesting read and pretty much correlates with what I heard from an academic earlier this year.
Looks like current darks are important and for aesthetic purposes a median smooth may help some of the noise that doesn’t respond to sigma clipping – on account of not being from a Normal distribution.
It does make the QHY600 a very attractive prospect.
Nice to see CMOS has finally (nearly) caught up with CCDs. I first remember hearing of them from a friend in the mid 90s – the noise characteristics then were hideous.
Of course a 123MB image is a little worrying. I might need a 2TB drive a bit sharpish, if I bought one of those.
Thanks for the reply.
Yes, I did look at the SX Mini wheel but it doesn’t accept 2″ filters and weighs pretty much the same as the Midi anyway – 800gms or thereabouts.
The Trius 694 clocks in at 450gm. I doubt if the Lodestar guider makes much difference.
So the whole thing is a decent weight – which seems a lot at the end of a thin Newtonian tube. 🙂
I will try tightening the central screw by tiny amounts every evening and see how it gets on.
BTW the Midi wheel can take 2″ filters – it has two wheel options.
Our local sports field expressed a desire to be dark sky / wildlife friendly when they replaced their halogen tennis court lights. Unfortunately, the difference in quote for less blue lights made them unaffordable for a small sports club/charity. At least they tried.
However, it looks like the fitters are not aware of the idea of light spill and the field next door is illuminated directly over 400m away… Bizarre.
I am imaging JUICE at the moment and after stacking 5x 60s frames (aligned on the star field) I could see a hint of the track. As its a hazy night, that sounds like the bright end of 18th mag. Will do some proper sums tomorrow and post the picture.
Tonight it is 1.4 million miles away.
Time to break out Tycho tracker I think. Will be interested to see how far we can push things.
Just processed my results from last night. JUICE was at mag 17.3 using an unfiltered Trius 694 and Gaia g comparisons.
JUICE was SNR=15 in 30s exposures this evening – must get the OAG going again.
Have never really checked. Managed 20.4 with the 10″. Got a Z=5 QSO but the unfiltered mag of that was uncertain as a lot of the light was shifted into the red – am guessing mag 20.8. Suspect that on a good clear night with a high target and no Moon I am looking at 21. Would need to be an interesting target. 🙂
just did a quick unfiltered imaging estimate of the magnitude of JUICE around midnight 17/18th April and get 16.3 with a fairly steady value and a position that agrees with JPL Horizon at the <1 arc sec level.
Will try again tonight…
I can’t imagine what you mean. 🙂
I never quite established what it was the Avast had done, but it lost contact the moment it started its update. Took me 2 evenings to coax it back to life – worked fine via keyboard, but refused to talk over Wifi. Fine now…
I think its fortunate that I attended a failing North London comprehensive in the 1970s. It equipped me with the robust language skills I needed to properly describe exactly what I thought about the staff at Avast, the authors of Windows 10 and life, the universe and everything.
Lets just say …. I was somewhat vexed.
Were it not for an Avast antivirus software update knackering – in a very subtle manner – the ability of the observatory PC to talk to the house, I would have been imaging at the same time as you – before the mist started rolling in about 12:30. Looking at my post meridian flip image sequence, the stars are gradually fading as the transparency went to pot.
Will measure some brightness values later…
Currently looking at the location suggested by JPL Horizons and am really surprised by how bright this thing is for something man made half a million miles away.
And thats under murky conditions. Image at https://britastro.org/observations/observation.php?id=20230418_002705_da18d9fe717fc9b0
Nice one!
here it was cloudy one night, then I had an equipment failure the next… Might have another clear night in time for the first flyby. 🙂
Separation of the Juice spacecraft from its launch vehicle was confirmed a few minutes ago. Its on the way!
Something to look forward to imaging – if it clears tonight.
Yes, I could make the code look for the TheSkyX COM process running and try to interrogate it for what the current pointing is, catching an error if need be. I have never bothered as I usually take many dozens of images of the same target and use a platesolving script that feeds the RA/Dec coordinates of the previous frame solved into an astrometry.NET instance. Upshot is that solving the first frame is slow, but the later frames solve in a second or two (depending on how many cores I use).
Worth thinking about – after I make the code rattle through the filters….
I just had a quick look at the ASTAP manual.
If I am reading it right, then ASTAP needs two FITS keywords* populated with the approximate field centre coordinates in RA/Dec and also guidance from the user (field diameter/search size) to run. So, its not doing blind solving, but the much simpler user assisted solving. Which probably explains the speed.
I’m not sure though how most of us would get the RA/Dec values into the header. Is there a command line tool or something available? I imagine you could supply a target name and the software then use Simbad or JPL Horizons online to supply the current position from your lat/long.
Does anyone know of such a tool? That would be extremely useful – and not too hard to write in Python.
Certainly, I control my telescope via TheSkyX, but I don’t like its imaging interface and so use my own CCD control software (or sometimes AstroArt) – which just takes images and does not talk to the mount. I imagine others may also be in the position of generating FITS from their camera without RA/Dec coordinates in.
*Or possibly 4, as I have seen two different definitions of keywords for RA/Dec.
Thats interesting. Glad to hear its still being developed.
Not sure a large circular aperture is always what you want for a comet, but its certainly a start.
