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Thanks Alex for the reminder. Im looking forward to monitoring this long event. I am in the shadow and it could be one of the longest durations. We will see. My PB is a 29 second event. There is also the slim possibility of detecting a moon. The more observers there are, the better we can probe the space around Medea.
Good luck.I see on Denis’s images that JWST is about 3′ arc North of the HORIZONS position at my location in Oxfordshire. This is what my college maths gives me: (300/350,000) x 57.3 x 60 = 2.9′ ( Denis is 300 miles north of me). I don’t expect any prizes, but its good to exercise the brain cells from time to time.
The HB front cover of Constellations & How To Find Them (W. Peck) indicates the direction of JWST. Follow church spire up a bit and there it is. The only imaging i’ve done in 10 days !
Edit: Congratulations to Denis for some fine images on successive days, and good news (on 30th) that fuel reserves are greater than expected due to the excellent Ariane launch profile.
When i enter the info asked for i get a load of stuff about JWST in red, but no list. Is there a glitch with the system?
My thanks to the nine observers who indicated they would be attempting this, but were clouded out ! I had set up a second telescope (8″ F/4) in the garden to make a duplicate observation by video. This could be compared with the CMOS camera.
What i found were a few technical problems with the video setup, which I was able to correct. So this was helpful at least.
Tim
Richard/All, Good luck to everyone tonight. The weather forcaste over Oxfordshire has been variable, A day ago it was 100%cloud. Now only 15%. So i live in hope that I get a chance, and Moon light does not interfere.
Tim
These are good observations from our European friends. British observers were on chords near position (3) on the DAMIT shape model (see Link from Alex) where the duration was about 25 seconds. This area of the profile was sparsely covered as a result of obscuration by cloud.
I was clouded out and this is the same story for many. However there are a few lucky observers in Europe who got a clear view of the occultation. Thanks to all who peeped outside. There are few opportunities to see (2) Pallas occult a star of sufficient brightness. This was one of them.
There are many asteroids and many stars, and the best place to look for predictions for favourable event is Steve Preston’s pages: https://www.asteroidoccultation.com/
The Asteroids and Remote Planets Section will be pleased to receive your observations.
Tim
Great video – thanks for the link Alex,
For those who may inquire, why telescopes shine lights into the sky? Well from what i understand this is part of the adaptive optics feed-back system. It doesn’t effect the images. A wiki would be the best place to seek further info on this.
TimGrant: Yes, time dependent events like this are particularly prone to weather conditions. There are 25 observers across Europe, 7 in the UK that i know off. Best of luck to them all. A number of chords across the asteroid will help refine its shape. We have no direct imaging, and based on light curves its not spherical.
To update you Alex, i connected my QHY174m-GPS camera to a 50mm F/3.6 finder. This was from Orion Optics originally but suspect it is a standard design. The instrument was in the polar home position. I adjusted the three finder alignment screws to bring the pole star a bit nearer the center using an eyepiece, then plugged in the camera. The scope had been parked from the previous nights observing. I focused the camera and the pole star was at the edge of the CMOS field. Its not necessary to have the pole star detected though.
I went through the routine with ShapCap Pro which is well explained with on-screen popups. The offset was measured from the automatic plate solving as 7′ arc. This was from a drift alignment originally but i knew it was a bit off. Polar alignment plate solve is build into the routine. Then i moved the scope 90 degress in RA as requested by Sharpcap.
After making corrections to the alt/az screws the routine reported 1′ arc. I could have got a bit closer but reckoned I was at the limit of the adjustment screws on the mount. So i settled with this. Now the guiding is very good indeed and gotos are spot on.
Cheers..
Hi Alex,
Thank you for your reply. My solution was to set up a similar arrangement with the dew band around the C11 OTA, and a Celestron dew shield over the top. The Celestron dew shield is quite heavy, so your foam mat is a better idea. Im now using my Newtonian in a Pulsar 2.7m so dew is much less of a problem.Cheers –
I wasn’t aware there was an earthlier design. The 2.2m Pulsar dome is advertised to have the dome drive – apologies for the miss information.
I agree with Jeremy. I had considered exactly the same proposed setup as yourself, but concluded i wouldn’t fit in the dome with the scope 😉 However i suggest that a motorised dome rotation would overcome the narrow slit difficultly. It works very well on my 2.7m Pulsar. I align the aperture on the OTA, and select sidereal rate on the control box. The azimuth drive system can be retro fitted.
I also find the variable bright at r 12.88 +/-0.05 (Unfiltered CCD, GaiaDR2/Astrometrica). Poor conditions of drifting high cloud in Moonlight Measurement were from start, mid and end of a frame sequence at 5s intervals for 20min.
A web-cam on the finder is a useful arrangement. Since i already have a 9×50 finder and a suitable camera, i bought one of these from FLO: https://www.firstlightoptics.com/adapters/astro-essentials-sky-watcher-9×50-finder-to-t-adapter.html.
Agreed, Its helpfull to have some form of dark frame subtraction to remove hot-pixels if the web-cam is used with longer exposure settings. False stars can be confused with real ones !Thanks Dominic, I will contact Novatech who made the laptop which is W7 i3, 4GB and SSD. I have now overcome the initial memory problem.
When I installed the 64bit version of Anaconda3 (2020-11) and HOPS 3.0.1, and use by own FITS files from a QHY174 – which are 4506 K each – HOPS progresses all the way to a preliminary light curve. The program analysed 1300 FITS files in about 30min, with 65% memory usage and 20% processor power.
The computer falls over when trying to process 32000 K FITS files often used in a Tutorial. So although the the HOPS 3 Manual says 4GB RAM or more – the relevant word is “More”. I would say my camera was typical mid-sized 12/16 bit CMOS, and these smaller files are handled OK with the old computer, and ageing operator !
Alan
With the WAT910HX / RC you have the makings of sensitive asteroid occultation timing setup. The addition of a GPS video time inserter, a larger aperture lens and a controllable mount is all that is required in terms of hardware to make useful observations. A clear sky would be nice too, but we can hope.Tim
