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Further to my earlier observation of JWST I did a follow up observation last night (14/01/2022). Interestingly the brightness followed exactly the same curve as on 05/01/2022. In the graph I have plotted the two curves together to do this I time shifted the data for 14/01/2022 by 9d 1.173 hours which gave the best alignment. The 2 additional spikes in the data for the 14th were also seen by a friend who observed on the 12th. So it seems the pattern repeats on a daily basis. What this means for the movements of the spacecraft or the angle of illumination is an interesting question!
As you say maybe the sun / telescope / observer angle doesn’t have to change much for a big variation in brightness given how shiny it is.
It will be an interesting project to see if glints are predictable. I previously did some work predicting glints from classified satellites with some success. The calculation is basically a whole load of co-ordinate transforms.
I imaged JWST on 05/1/2022 for just over an hour and in that time its brightness seemed to vary quite a bit as seen in this stack:
This graph shows the brightness of JWST over the period compared to 3 other field stars of similar brightness
I was wondering what caused this variation because I assumed the spacecraft is not rotating and that the change in viewing angle over this time period would not be that great.
A nice clear evening came along just at the right time much to my surprise. Some fascinating links and images on this page. Thanks to all9 December 2020 at 9:39 am in reply to: Novae Cas and Per 2020 H alpha at medium resolution #583498
Thanks for you reply. Nice to know my observation and processing hadn’t created a spurious result! I’ve attached my result.
Phil8 December 2020 at 10:57 pm in reply to: Novae Cas and Per 2020 H alpha at medium resolution #583493
I tried taking a spectrum of the nova and got an apparent emission feature between H beta and H gamma. Very similar to David Strange’s result now in the recent images page. Is this feature real?
I’ve just posted a picture of the comet I took the other day. The problem I have is in the processing stage when I use Deep Sky Stacker to try and track on the comet and stars to produce an image in which both look sharp. I can get either an image tracked on the stars or the comet but it crashes when I try to do both.
Does anyone know a way round this? Or are there any recommended alternatives to DSS for this.
Any help would be great!14 May 2020 at 2:55 pm in reply to: Photometry on Supernovae with bright host galaxies? #582456
Have you tried Astrometrica? It’s free for 100 days then 25 euros. It models the star’s PSF I think. I have used it for the SN in M61 and NGC 4568. The latter is very much within the galaxy so background subtraction is important . Attached is a screen shot of the NGC4568 results.
In June of 2018 I saw Venus with the naked eye at about 16:00 UTC when the Sun was at an altitude of 30 degrees. To do this I used my GOTO telescope as a guide as to where to look. The sky was particularly clear and a deep blue which suggests not much of the usual milky haze we get in the UK. Even so spotting it wasn’t easy if I looked only a degree or so off target then finding it again was tricky.
I’ve never seen Jupiter with the Sun in the sky.
By the way I grew up in Rugby and have many happy memories of observing there. Attached picture is Venus (barely visible!) from Rugby in 1983.