This page is devoted to special, outstanding, exceptionally rare occultations of stars by minor planets which will occur in the near (or not so far) future. These are events never seen before - for example, occultations of first-magnitude stars on the dark sky in highly populated areas.
Date UT Asteroid Dia Durn Star Star Visibility
Year Mon dd hh:mm-mm No. Name km secs mag Name region
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2005 Oct 19 4:23-25 166 Rhodope 35 1.1 1.4 alp Leo Spain, Italy, Greece
2014 Mar 20 6:04-18 163 Erigone 72 14.1 1.4 alp Leo Eastern USA and Canada
2023 Dec 12 1:09-27 319 Leona 68 6.4 0.5 alp Ori Turkey,Gre,Sic,Tun,Alg,Mor,Cuba
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This event was first predicted by Italian Aldo Vitagliano using SOLEX software. I found it independently in April 2004 with WinOccult program by Dave Herald from Australia.
Search on the web for Leona and Betelgeuse (alpha Orionis, alf Ori or HIP 27989) gave no results, so probably this unique occultation was discovered by me in April 2004 (first announced during the talk at Russian AstroFest, published in internet on October 3, 2004).
This occultation deserves a more detailed description. It will be exceptional not only because of the star's brightness, but also of its angular size. According to interferometric measurements, red giant Betelgeuse has a diameter of about 50 milliarcseconds (several hundred solar diameters at 400-500 light years). But star is changing its brightness due to pulsations (alpha Orionis is semiregular variable star). More information about Betelgeuse can be found, for example, at this page.
By coincidence, angular diameter of Leona on December 12th, 2023 will be also about 50 mas (52 mas, if we take diameter estimate of 68 km). This means that the occultation of Betelgeuse will be something totally different from other asteroidal events, being rather like solar eclipse. The partial phase in the center of path will last about 12 seconds (6 sec from first contact to the maximum eclipse, and another 6 sec to the last contact). Path width will be twice larger than it would have been in case of point source. Observations in different parts of shadow (or penumbra) will allow to measure the distribution of brightness over the stellar disc.
If the asteroid's size will be larger than diameter of Betelgeuse, the total occultation will occur in a narrow zone on Earth with magnitude drop of 13.3m. The actual size and shape of Leona are not exactly known, but they can be determined in the mean time during other stellar occultations by this asteroid. To know the profile of Leona on 2023 Dec 12th is very important for analyzing the occultation data. No occultation by Leona has been observed as of October 2004. The next observable event occurs on November 6th, 2004 in south-eastern Canada and mid-USA. Star to be occulted is in Taurus near Orion border and has magnitude of 11.5. Here are preliminary path map and 5x5 degree finder chart.
