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Thanks Jeremy.
Miguel Montarges is the lead scientist of the Leona-Betelgeuse pro-am campaign and he has just e-mailed the group to mention that they’ve received over 100 observations, and 75 of the light curves are almost not – or not at all – affected by clouds. Recordings were obtained using various filters, so they should be able to measure Betelgeuse’s diameter at a range of wavelengths.
As a very provisional example, Dave Herald measured a light curve obtained in Ha by Alfonso Noschese, and after applying a large limb darkening coefficient it gave a diameter of 60 mas.
https://ukoccultations.groups.io/g/main/message/3036
The campaign team also hopes that the dataset will detect the huge convection cells in Betelgeuse’s photosphere.
Cheers,
Alex.
It is very sad to hear of Roger’s passing. He was a true gent.
One story I can relate – after the VSS Workshop in Edinburgh in October 2008 I suggested various eateries along the Royal Mile, but Roger gave me a gentle ribbing because every place we checked was full. Eventually, we tried the restaurant at Deacon Brodie’s and they accommodated us with several tables for our group. With a grin, Roger said I had redeemed myself. 🙂
Melvyn Taylor left a large archive of unrecorded VS observations (thousands submitted by VSS observers and thousands of his own). Roger was a great help in graciously receiving my almost interminable scans of the report forms per star and he coordinated with the small group of data input volunteers to upload them into the VSS database.
He will be missed by many. My condolences to his family and friends.
Alex.
I and a number of my contemporaries joined the BAA in our teenage years or our 20s, then as impoverished students our memberships lapsed until when in our 30s or later we had more spare time for our hobby and could afford the annual subscription. None of us are eligible for Honorary Membership and I guess that 50 continuous years will become a rarity.
Proposals to support younger members – and retain them – are welcomed.
Alex.
Hi Ian,
Here’s a link to using the drift-scan technique for occultation events
https://www.asteroidoccultation.com/observations/DriftScan/Index.htm
I’ve no experience of using it, and the Betelgeuse event was gradual.
All observers who attempted to observe the Betelgeuse occultation are requested to submit a report form and their raw data to the pro-am campaign team in Paris. This is discussed in Josselin Desmars’ presentation
(PDF in this link)
https://share.obspm.fr/s/aYzPBYByoEL2xZY(video at this link – talk begins at 1hr 51m)
https://astrotube.obspm.fr/w/isuxhMSJZ5FNNPKeT3AZbbCreate an account on the Occultation Portal
https://occultation.tug.tubitak.gov.tr/then upload your report file and data (see other methods if files are very large). The Paris team will analyse your data.
Alex (back in ‘sunny’ Leeds)
Even if you cannot avoid image saturation, your data could be valuable. Most setups for this event are configured to monitor the descending and ascending branches of the light curve. A camera that is saturated before the occultation could contribute data on the deepest part of the brightness dip, particularly if it’s >2 or 3 magnitudes.
Alex (in Alicante)
Hi Ian,
Drift is a good option. Driftscan software can process your capture. Please record for about 1 minute before and after the mid-time given by the Interactive Map of the Paris ‘Lucky Star’ prediction
https://lesia.obspm.fr/lucky-star/occ.php?p=131608
Avoid saturation at all costs. If you can’t apply a ‘many-holes mask’ as suggested in the last-minute advice (above), try your R or SII filter with a brief exposure time. A H-alpha would attenuate the light, if available. A small amount of defocus is fine.
Take darks and flats.
Good luck,
Alex (in Alicante)
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On https://www.virtualtelescope.eu/webtv/Gianluca Masi, Italian astronomer and developer of “THE VIRTUAL TELESCOPE PROJECT”,
has posted the following announcement :Next event: “Betelgeuse occultation by Leona: live view” –
12 Dec. 2023, starting at 01:00 UTCA while after 01:00 UT on December 12 Betelgeuse will be occulted by asteroid (319) Leona. It’s very rare for such a bright star to be occulted and this ‘once in a lifetime’ event will be used to model the photosphere of Betelgeuse.
Recent occultations of other stars by Leona have determined its dimensions, showing that it subtends (perhaps) a slightly smaller apparent diameter than Betelgeuse, giving a partial / annular occultation of 11s duration. The 142 km-wide shadow track passes over China, Turkiye, Greece, Italy, Spain, Portugal and southern Florida (USA), and more than 80 observers are participating in this pro-am campaign. They will record the occultation using various filters and some teams plan to obtain high resolution spectra.
https://call4obs.iota-es.de/2023-dec-12-0110-ut-319-leona-occults-betelgeuse-alpha-orionis-0-5-mag
Alex.
Blue dot marked by a white circle.
Attachments:
See the attached cropped image from the PDF version of the latest Journal.
Alex.
Attachments:
During the webinar, the speaker repeated that “…T CrB will soon be the brightest nova in living memory…at mag 2…” Someone commented in the Chat box that Nova Cyg 1975 (=V1500 Cyg) reached mag ~1.7. (BAA VSS database ~1.5).
Perhaps he meant the brightest known recurrent nova.
Many observers enjoyed seeing the ‘new star’ in Cygnus in August/September 1975, including myself, and I look forward to observing T CrB in outburst.
Alex.
First chords observed across asteroid (7102) Neilbone
The European SODIS database (Stellar Occultation Data Input System) now lists two observations of chord timings across asteroid (7102) Neilbone. They were obtained from Switzerland on August 19 and France on September 7. This main-belt asteroid has a diameter of ~22 km, so it’s a challenge to obtain multi-chord observations of the same event.
These chords will help to confirm its diameter and will provide high-quality astrometry to refine its orbit.
Neil (1959 – 2009) was well-known in UK astronomy as a keen and knowledgeable observer and a publiciser of many branches of astronomy, and in particular aurorae, NLC and meteors – he served as BAA Meteor Section Director (1992 – 2009).
Alex.
Attachments:
Special Webinar: Recurrent Nova T CrB Coming Soon to a Sky Near You – Dr. Brad Schaefer, Professor Emeritus of Physics and Astronomy at LSU
https://us02web.zoom.us/webinar/register/8116929086840/WN_Pn59ESvzQOiSQzLHULi4Ig#/registration
The comet’s elongation from the Sun is <35 degrees, giving amateur searchers an advantage over the big surveys. Objects ‘coming out of the Sun’ are a challenge.
Alex.
