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Occultation of Betelgeuse by (319) Leona on 2023 Dec 12

The occultation of the red giant Betelgeuse (α Orionis) by the asteroid (319) Leona is an extraordinary opportunity to gain new knowledge not only about the asteroid but also about the star.

Due to the apparent angular size of Betelgeuse of about 50 mas and the asteroid of about 46 mas, it is possible that an annular occultation of the star will be observable. The profile of the asteroid will not completely cover the star disk and Betelgeuse will not disappear completely when observed with a telescope.

The shadow path of this stellar occultation runs in Europe from the east across Turkey, Greece, southern Italy and southern Spain and Portugal. The shadow then crosses the Atlantic and will pass southern Florida in the US.

The accuracy of the path prediction was improved with data of the very successful observations of occultations by (319) Leona on September 13 in Spain [1] and on September 16 in the US. JPL has updated the ephemerides for the asteroid. This new data and the astrometry for α Orionis from the USNO Bright Star Catolog (UBSC) was used for the following predictions.


Path prediction for the occultation of Betelgeuse by (319) Leona on Dec 12. Path calculated on 2023 Sep 30 with Occult V4.2023.9.26.
HIP 27989 (Path prediction on December 12:Betelgeuse, α Ori) by 319 Leona on 2023 Dec 12, at MSLa.kmz

Join the Observation Campaigns

Preparations are already underway in Italy and Spain to jointly observe this stellar occultation.

In Italy, the campaign is led by AstroCampania ETS- l'astronomia amatoriale in Campania:
Website of the Italian campaign  (website bilingual: Italian/English)

Spain prepares the observing campaign on the Discord platform under the name OCULTAAS. Registration is necessary. (Spanish, communication in English possible)
Discord Platform

In France, interested observers are informed on the website of GEMINI - Coopération Astronomes PRO-AM:  French website (in French)

An introduction to the occultation by (319) Leona on Dec 12 by P. Slansky and B. Gährken has been published on the website of the Vereinigung der Sternfreunde (VdS): German Website

IOTA informs about the current predictions in the US: IOTA website

At the IOTA Meeting 2023 in July D. Dunham reported about this occultation and the observing possibilities in the US. A video recording of his presentation is available: Presentation by D. Dunham