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Alex – Well done for trying. At least you didn’t miss a positive from your observing site!
I have had two similar experiences; one when a few minutes before the predicted time, a cloud appeared from nowhere in a clear sky and prevented any timing. And another occasion when I had to travel 12 miles to get to my observatory so by the time I got there the sky had started to cloud over badly. I set up and managed to have enough sightings of stars to set up pointing the telescope in the right direction and, low and behold, some minutes before the due time a sucker hole appeared allowing me to achieve a timing.
Richard
Thanks Nick for monitoring this event. The weather forecast was borderline and with such a low altitude it was likely to have been affected by clouds towards the local horizon. That’s what happened with Alex Pratt just 3 minutes before the predicted time but I must say I did not expect Alex to have a clear sky full stop. I see that Phil Denyer also recorded a negative observation from somewhere in London. His result may shift the position of the shadow track further west than yours does. The shift has a bearing on the exact prediction for the forthcoming May 21 stellar occultation involving 29P, that will be visible from across Spain but at a similarly low altitude in the sky. See:
https://astro.kretlow.de/cora/occultations/da2f2c54-7d6c-4f12-a56e-8aeeaf7efd0b/
This involves quite a bright star (~9.8R) so fast video should be possible provided the sky is clear.Interesting – I see there is a fairly bright star mixed up with the inner coma.
I can do absolute photometry on the coma using a capsule aperture.
I have first subtracted stars manually from within the coma using SalsaJ on the non-offset FITS image.
Using AstPhot32 I can go up to an aperture 200 pixels across and many hundreds of pixels in length.
This way I would not use the offset stack, which I am suspicious of because the stars are not completely eliminated.Can you suggest what size aperture encompasses all of the coma – similar to what the eye would record?
I can make sure I go beyond that with the multi-aperture photometry.Richard
Mark – Thanks for signalling that ASTAP might be suitable for comet photometry. Please pursue this and see where it leads.
Paul, yes – circular apertures are just a special case of elliptical ones, which can also be adjusted for any tilt angle. Interestingly, there is also another form of photometric aperture used by pros called the ‘capsule aperture’, which is like a rectangular aperture but it has a hemispherical form at each end of the narrower sides of the rectangle. It is used for the photometry of trailed images.
Roger,
Can you expand a bit about your phrase, “to process exoplanet phase curves”?
The software aims to identify periodicities in data, so it needs lots of data spanning many cycles. It might be helpful if you take everyone’s data going back several years and search for the periodicity that way.
Richard
Alex – Yes exactly that. Urban areas that are badly light polluted (i.e. counting 10 or less stars is the criterion) seem to have improved somewhat.
I suspect that the darkest skies may have deteriorated slightly.
I have some peripheral involvement with the CPRE Star Count and we know that the weather badly affected reporting in 2022 cf. 2021.
I know that National CPRE used paid ads on Facebook to help spread the word in 2021 and several local groups also promoted it.
I intend to get actively involved in promoting the 2023 effort.Good to have this update on that particular aspect of remote telescope time.
Another possibility that Grant is well aware of (he has used this for variable nebulae studies) is the Europlanet Telescope Network.
Early last month I had an online meeting with several interested parties closely involved in the ETN, and I am planning on progressing the BAA’s further involvement after several weeks delay on my part – That will be an offline discussion once I’ve submitted a report to Council on the subject.Richard Miles
Well done guys !
The Handbook has some historical value.
Interesting how the Asteroids part has evolved over the years as new objects and new classes of object are discovered. Similarly the opportunities for observing asteroid occultations has grown dramatically and continue to improve as Gaia completes its work over the next few years.
Michael – Great!
There are various lists of asteroids named after people but the key is to use the citation to verify such a name refers to an actual BAA member and not just a person having teh same name as a member.
On the subject of discoverers who are members, it used to be a pain finding out who had discovered one or more asteroids, but not anymore since last September the following page has appeared on Wikipedia:
https://en.wikipedia.org/wiki/List_of_minor_planet_discoverers
Richard
Hi Michael.
About 14 years ago I started to compile such a list in the form of a spreadsheet but gave up as it was, at that time, difficult to find all the necessary info. Since then the Web has gone from strength to strength and it is definitely much easier to glean that information. If you like we could work together to update my original spreadsheet? Are you keen to give it a go? We would just work together under data protection rules to achieve this.
I had an ulterior reason for compiling the list – that is to run a project under ARPS to observe these objects and to discover their rotation rates. Fortunately we now know these values for some thousands of asteroids and so maybe a lot less work would be involved than originally envisaged.
Thanks for posting that Michael.
At some 1km across it is very large and being only about 2 million km from us it turns out to be the brightest NEO in the last 4-5 years reaching magnitude 10 and so very observable. You have caught it the evening after closest approach when it was still bright at 11th magnitude.
Thanks Alex for letting folk know about this new survey that looks to have started on December 13.
It’s quite a straightforward, easy survey to complete. My two-penneth has been added as an individual amateur. I see that it is possible for an amateur organisation to respond via a group response. Maybe the BAA has a ‘corporate’ view on some of the items in the survey?
I encourage all interested amateurs having a view on Pro-Am matters to complete the survey, which is a worldwide one.
You can tell we are well into the 21st Century when you see detailed images of asteroids measuring small fractions of an arcsecond in size. The paper includes density measurements of these bodies, which is rather amazing.
There again, the latest BAA Journal has some amateur images of Mars, Uranus and Neptune that were unthinkable say 50 years ago!
Len – Thanks for that – Alan Bowden, one of the named authors is an old friend of mine – I could follow it up with him.
Hello there Jeremy – I don’t have an answer but I see the photo is by a certain Mike Peel.
A chap of the same name used to be a BAA and VSS member. Is this the same MP, and has he rejoined if so I would be very pleased to know that. Mike used to live in Lancashire.
Might you try and contact the photographer to see if he has anymore info.
Richard
Thanks Paul for highlighting this discovery, which is remarkable and shows what is possible when a large 4m scope (DECam Survey) searches the twilight sky. As well as the shortest known period, 2021 PH27 also has the highest precession rate of 53.5 arcseconds per century (a consequence of general relativity in operation), i.e. gretaer than that of Mercury.
As to the Handbook for 2022 that goes to the printers tomorrow! But in any case, it wouldn’t get a mention under any of the various categories. Usually we try and put stuff in that means they can be observed by amateurs. It might be worthwhile to list Inner Earth Objects provided that they can reach say mag 20 at some point in the year plus some criterion as to teh lowest practical solar elongation. Of course the two are inter-related so we might have to use a sliding scale of acceptability which is a function of both magnitude and elongation. If you have a go at reaching it next March and succeed that would help to set the limits. At about mag 16 the limit is an elongation of about 19 degrees for our UK latitudes. Ther may be a problem about adding a new category to the Handbook and that is the number of pages limit. To add the Exoplanet data I had to shorten the brighter asteroid Asteroid Ephemerides.
Richard
