[murphyslab]

It appears that astronomers are already preparing for the upcoming occultation of 319 Leona with Betelgeuse.

Researchers in this July 2023 presentation note:

> Leona’s Long Rotation Period (430h) complicates determination of its size and shape.

> So it is VERY IMPORTANT that some OTHER occultations by Leona be observed from multiple stations BEFORE December 12, to take best advantage of this unique opportunity.

[0] https://occultations.org/publications/rasc/2023/2023Dec12Leo...

And there is already at least one other set of observations reported on arXiv from a September 2023 occultation:

> The stellar occultation by (319) Leona on 13 September 2023 in preparation for the occultation of Betelgeuse

> This represents an extraordinary and unique opportunity to analyze the diameter and brightness distribution of Betelgeuse's photosphere with extreme angular resolution by studying the light curve as the asteroid occults the star from different points on Earth and at different wavelengths. Here we present observations of another occultation by Leona on 13 September 2023 to determine its projected shape and size in preparation for the December 12th event.

[1] https://arxiv.org/abs/2309.12272

(Amazing that it was posted ~8 days after the observations were made!)

[russdill]

Why must the observations of other occultations be done before and not immediately after?

[murphyslab]

The recording of the meeting discussing the presentation [0] notes three issues with occlusions by Leona:

1. There is uncertainty with regard to the path, i.e. exactly where will it be projected on the surface of the Earth.

2. Size of Leona is uncertain, hence the expected magnitude of the decrease in brightness of Betelgeuse as a result of occultation was uncertain. A bigger decrease means that it's easier to get the public involved in observing.

3. The group looking at this is doing citizen science. They need to know the above in order to decide how much to involve public because this is something where if the above is known, then the public can participate with DSLR cameras and record light curves suitable for astronometric analysis.

[0] https://www.youtube.com/watch?v=ok7hJ_2DPhM&ab_channel=IOTAA...