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Yes, I saw that on the recording.
The volcano appears not to be getting any worse, nor better, but is undoubtedly changing. The latest sign is the appearance of elemental sulphur on the surface around the top of the cone. If you read Spanish, or know how to use a web translation service, this link contains a good picture and an explanation: https://www.eldiario.es/canariasahora/lapalmaahora/aparicion-depositos-azufre-elemental-apuntan-cambio-claro-dinamica-volcan_1_8464747.html
There are (at least) two ways round the text file attachment issue. The obvious is to put your text into a doc/docx/pptx file. The recipient can then convert it back to text with a simple cut and paste.
The other is to rename the file because the uploader works on the extension not the contents. See here for an example.
I had not heard that a 4″ Unistellar can make useful observations of exoplanets but knew that a 6″ reflector most certainly can. It is good that I am now better informed.
As noted, much smaller apertures, a Mark-1 eyeball and some way of taking records is all that is essential.
Eric: I strongly agree with you emphasis on scientific value. The BAA has had a strong ethos of scientific research for its entire existence.
In my view we should be investing more heavily in spectroscopy. We’ve been doing photometry very productively for well over a century now. Precision astrometry is a more recent phenomenon but now well established. Spectroscopy remains a field sadly neglected by most amateurs, though some impressive work is being performed by BAA members. I say this as someone who is not (yet) a spectroscopist.
I recognize that La Palma isn’t an ideal site right now but the eruption will be over long before any kind of decision is made.
Kevin Hills runs a robotic observatory with a 0.5m Newtonian astrograph on my land. He has used it to do some very good science.
Between his dome and mine is a concrete pad with power and ethernet supplied to it. A few years ago a European university ran a robotic observatory from there.
Here is a view from above:
https://www.google.es/maps/@28.6418055,-17.8679749,125m/data=!3m1!1e3
or search for “Tacande Observatory”.
Just saying …
No significant problems reported so far by the evacuees living there (SWMBO and I returned to the UK on 2021-09-22) other than perhaps 5cm of ashfall, the vast majority of which will not have settled on the dome. Everything inside is wrapped up well each time we leave because even 3 months of regular calima dust is tiresome to clean off the optics. The quakes have been far too small to damage anything.
The original vent is 3.1km due south. A subsequent one is about 500m closer to us. Both are the far side of a substantial ridge which protects us. Of course, if another vent opens up on the north side …
Our plan is to return in February. Kevin and I will doubtless have a much better idea then.
(added in edit) See https://britastro.org/observations/observation.php?id=20211017_203048_828e0db6c3bb0b61 for a recent image of the volcano and observatory. Inside the latest The Astronomer magazine is one taken a very few minutes after the start of the eruption.
See http://www.astropalma.com/equipment.html
Shows it much better than I can describe it.
My 120mm refractor / autoguider is mounted on top of the 400mm Dilworth, all inside a dome. As long as I am observing reasonably close to the meridian the scopes are aligned along the slit, not across it. Observing extremely close to the zenith results in the 120mm being hidden behind the slit shutter.
Thanks for posting this. A fascinating paper.
Likely useful not just for planetary observers. Obvious DS applications are to clean up globular clusters and galaxy clusters.
The aim is to create an artificial star of known size and shape. A very narrow laser beam tuned to exactly the same wavelength of sodium light stimulates fluorescence at the same wavelength from sodium in the upper atmosphere. (Incidentally, that sodium comes primarily from sea salt.)
A telescope looking at that fluorescent spot should see an immobile spot with a shape and diameter set by the resolution of the optics. In practice it sees a large shimmering moving blob because of the atmosphere. Clever software quickly works out what distortions should be made to the telescope to return that blob to its undistorted shape and very fast mechanical actuators then make the corresponding movements to an optical element. Voila, diffraction-limited images through adaptive optics.
If you watch the video feed for long enough you will find that at some times that happens about once a minute. Sometimes the vents do little but leak gently; sometimes they explode and send material hundreds of metres into the air.
Note that the side of the cone has collapsed. I watched much of that happening in real time.
All rather interesting as long as you are at a safe distance.
I have found it majestic and hypnotic but not, perhaps strangely, scary. That’s the case whether watching live or over the net.
Last night (i,e. 24 hours after the above posts) it became markedly more explosive with enormous lumps of lava being thrown a hundred metres or more into the air. It was hard to judge scale but some of those pieces must have been well over a metre in diameter and so weighing several tonnes each. I was also watching what started out as a very minor effusive vent become much bigger and explosive.
Excellent live coverage at https://rtvc.es/en-directo/
It helps if you understand Spanish …
Their live feed from the Cumbre Vieja shows that large amounts of liquid are still coming out but the explosive gouts appear to be somewhat reduced from when we left several days ago.
Not now.
By chance we took out fire / flood / vandalism / etc insurance on our place a week or so before the eruption started. The insurance company didn’t want to touch our observatories so we were going to check for specialist companies when back in the UK.
It is possible to insure almost anything against almost anything if you are prepared to pay the premium.
This is a before and after image of an amateur observatory on La Palma. Note the apertures of the telescopes — 80cm and 50cm. Serious kit.
I never met Rico but exchanged email.
