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Hi Peter,
Here’s an inverted plot of the lunar limb generated by Occult from LRO/LOLA data. It’s for the location of Cirencester at 09:50 UT on 2022 October 25 to compare with James Weightman’s ‘Lunar Mountains Silhouette’ image.
https://britastro.org/observations/observation.php?id=20221025_124443_d85bceb02058323a
Note that the Occult plot has a linear baseline, whereas the lunar limb is curved.
I might not have used the correct limb angle in Occult, and as you view the limb in fine detail any discrepancy in the site location and altitude, or error in selecting the cusp angle, can cause a significant difference in the resulting limb profile.
Alex.
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Hi Peter,
The comprehensive occultations software suite Occult
https://occultations.org/observing/software/occult/
can generate a lunar limb profile for Baily’s Beads analysis (see attached)
I’ll have a look tomorrow to see if I can extract a limb profile matching our observers’ images.
Alex.
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Hi Denis.
It’s only on for two nights and thankfully they’re not blazing lasers into the sky like they did in 2020. My meteor cameras shouldn’t be plagued this time, hopefully.
Here’s their plans for other cities:
Cheers,
Alex.
Hi Nick,
Yes, it’s likely that a body with higher density or cohesive strength would be far less affected. The NASA news release says:
“The recoil from this blast of debris substantially enhanced DART’s push against Dimorphos – a little like a jet of air streaming out of a balloon sends the balloon in the opposite direction. To successfully understand the effect of the recoil from the ejecta, more information on of the asteroid’s physical properties, such as the characteristics of its surface, and how strong or weak it is, is needed. These issues are still being investigated.”
We still need to wear our tin hats…
Alex.
We almost take for granted the amazing guidance and control systems required to hit a celestial bullseye at those high velocities – and that the camera will be set to the correct ‘shutter speed and f-stop’.
https://www.nasa.gov/feature/dart-s-final-images-prior-to-impact
Looking forward to seeing the images from the CubeSat which was also monitoring the impact!
Alex.
NASA TV will be presenting live coverage from 6pm Eastern U.S time, which (I think) equates to 11pm BST.
Amateur and professional astronomers in the southern hemisphere have been asked to obtain photometry of the Didymos+Dimorphos system
https://groups.io/g/IOTAoccultations/message/72575
Alex.
Hi Alan,
Drat, double drat and triple drat!
I just wish we could have retained the old website, and that Microsoft had kept my favourite Windows XP, and…
Clear skies,
Alex.
Thanks Jeremy.
Hmm…Our very own Gordon Taylor worked at the RGO, not MIT (p. 176).
David Dunham gave an excellent presentation on the contributions of occultation observers in measuring the diameters and refining the orbits of NEOs (3200) Phaethon and (99942) Apophis
PowerPoint
YouTube video
https://www.youtube.com/watch?v=RoK3oUJXaxE
See also the Across Project
https://lagrange.oca.eu/en/home-across
Cheers,
Alex.
Hi Peter,
Have a look at a couple of pages of the Observers’ Gallery and you’ll see that some list their full ‘name, rank and number’. They can edit this in their profile.
Cheers,
Alex.
Hi Alan,
Have a look at
https://britastro.org/forums/topic/new-website-members-full-names
Cheers,
Alex.
Hi Daryl,
The light trends feature suggests that conditions have improved a little at some of my light-polluted locations and worsened at my rural sites. Hmmm. I leave it to others to investigate and comment on this.
Alex.
Hi,
To check the level of light pollution at a specific location in the British Isles (or overseas) I use
https://www.lightpollutionmap.info/
I find that its SQM readings and Bortle Scale estimates are in good agreement with my own obtained on my travels.
Additionally, use
https://lighttrends.lightpollutionmap.info/
to click on a location and generate a plot of the trend in light level.
Clear skies,
Alex.
After logging out/in a couple of times I was able to get a clean login to Edit my Web profile. I’ve now reset my displayed name to its previous shorter version.
Alex.
I received a copy of Starlight Nights when I was a youngster. It was wonderful and inspiring to read about Leslie Peltier’s journey of astronomical discovery. The attached image shows my first copy (1967) and the modern indexed version (1999).
A gem of a book!
Alex.
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I can’t see an option to allow me to edit my previous message. I should have written “If one of my videos is larger than the 2MB limit I upload it to my YouTube channel using one of its supported formats…”.
Alex.
