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Alternatively, how about setting up a scope at a hosted site and giving each section nights in turn so the VSS can go through dozens of VS a night, the comet section can do all comets visible from site and greater than mag 18, the Asteroid section could chase low phase angles and some compromise reached to allow good amounts of planetary observing at the most favourable point of the nights. You could cover a lot with a Paramount and co-mounted C11 and 11″ RASAs.
A simple criteria: data collected must lead to papers or it doesn’t get collected.
I use a 114mm Newtonian riding piggyback on the back of an 11″ RASA V1 mounted on a Paramount MEII. So, way within the mount weight limit. Seems to work very well (the 114mm is used as a autoguiding scope), but I could envisage trouble if it wasn’t being used in a roll off roof shed – as the slit of most domes would be too narrow.
While between OTAs, I have been using my 114mm guidescope and an unfiltered Lodestar to occasionally take some measurements of LL And. Because they were mainly taken on moonlit or partially cloudy nights (and I am a deep sky observer) I just let the camera run a series of 30s frames in the hope it might drive down the errors that would be present with such a small light grasp instrument. Its not the best way to do this sort of thing, but it was simple to do and fun.
To analyse the data, I wrote Python code to plate solve all the frames, locate all the stars, compare the catalogue stars to those on my frames, established the Zp for each frame and thus derive the mag of LL And. I then took the median result (mag1).
To make things more interesting, I also looked at 4 comparison stars from the AAVSO chart and derived mags (mag2) for those using the sums of the fluxes measured from all the frames. I may extend the number of comparison stars.
The results are these:
Date Mag1 Mag2 Magerr Frames
210917 13.15 13.32 0.15 122
210918 13.39 13.60 0.4 212
210921 13.71 13.90 0.25 307
210922 13.77 13.98 0.25 277
210929 14.58 14.71 0.35 156
211010 17.41 17.26 0.8 179
Usable results could have been obtained with far fewer frames, but I had hoped to see some evidence of superhump activity (yeah I know) so I just let it run.
What I am noticing from this – apart from how interesting LL And is – is that the Mag1 value seems consistently brighter than the Mag2 value. I won’t be submitting any observations formally until I figure out what causes that. Has anyone any thoughts on what I might be doing wrong?
EDIT: Andy worked out the problem and I am ashamed that I didn’t myself. One approach used the Gaia g catalogue mag values and the other used the AAVSO sequence mags ie V.
Thats really worth knowing. I shall try a copy the next time I see one….
The di Cicco reviews were always a high point for me. They could be trusted.
We did have an incredible run of clear skies though. I recall not using the 4th clear night in a row because I was so tired.
“I think imposing restrictions is indefensible”
Are you sure you mean this? I have never viewed defending those weaker than ourselves as indefensible. But this forum probably isn’t the place to discuss this.
Perhaps they want to know who is planning on turning up to avoid overcrowding?
I certainly wouldn’t relish sitting shoulder to shoulder with lots of people at present. I’m not planning on attending – other than via Zoom (if available) but would hope they would be advocating the wearing of masks…
Just a note to say that I finished an updated version.
It now works with all current Starlight USB cameras.
The big difference is that if more than one Starlight camera is attached, you get to choose which one will be used. That has the benefit that multiple instances of SXcon can be run to control up to 4 different cameras simultaneously.
Additionally, the configuration file changes mean you can have up to 4 alternate observing sites/gear setups. These are used to document the images better via the FITS header keywords (pixel size, long/lat, focal length etc).
Also, I improved the code internally to make it more robust to dodgy USB cables.
As before, anyone who wants to try the freeware code is welcome. Just email me.
Silly question, are there many TNOs etc below 20th mag that are uncertain in their orbits or are we thinking 20-21 mainly here?
Its also worth remembering – for astrometry certainly – that though a piece of software may say that a time given is the start, end or middle of an exposure it may not be as accurate as you would expect.
I recall some of the guys from Basingstoke society devising ingenious ways to determine how accurate the recorded time of a DSLR exposure was and finding not just the shutter/camera OS delay time, but also delays of more than a second in some commercial camera control software – which would play merry hell with NEO measurements.
The told the developers of one of the software packages, but they didn’t seem to care.
I was under the impression that the Apollo samples suggested that a significant portion of the lunar surface was formed from materials that were originally part of the Earth’s mantle. The lunar interior is rather harder to sample, though it does have a fascinating gravity field.
The magnetic fields are also very different.
As its water soluble I am hoping the rain over the next couple of days will flush some residue away away and beyond that I am hosing the joint to free up some of the debris left – even if it will wet every thing for a day or two. May have a bash with a cloth soaked with meths or white spirit. Its going to be a week or so until things are dry enough to try bonding again….
Just to clarify, it wasn’t the No Nonsense that failed drastically but a different brand. The No Nonsense sticks to about 75% of the gel coated dome but not all especially – where a thin coating. I really wonder if roughening with some emery paper or something similar might have provided a better key.
Thanks for the steer to Gorilla and DOW 785. Have been pondering one of the Soudals too.
I wonder if my mistake was in not sealing it with paint before the first rain.
I really had not expected the stuff to absorb the water under any circumstance – not the behaviour you would anticipate from a “sealant”. That sounds more like filler…
I had a couple of mirrors done by VCSM last winter/spring during the covid surge. I couldn’t call them speedy, but one of the mirrors had unusual coatings which took a while to remove.
New coatings look fine. Images seem clean.
They are on: http://www.scientificmirrors.co.uk/
