I was looking at the Wikipedia page for 319 Leona and I got excited to know that it will occult the bright star Betelgeuse on December 12, 2023 (It's predicted with the use of Solex application):

On 12 December 2023 at about 01:09–01:27 UT, Leona will occult Betelgeuse as seen from southern Europe, Turkey, Greece and Sicily. The 14th magnitude asteroid will occult Betelgeuse (block or reduce the light) for about 12 seconds. Betelgeuse is expected to dim by about 3 magnitudes. Light curve studies of the event may help understand the distribution of brightness over the disk of Betelgeuse.

Then I searched to find the map of this occultaion and I found this. Of course, the webpage is in Japanese. So I translated it.

Well, the world map was very hard to find if the occultation is visible in Iran or not. So I clicked on a link to a map of Turkey which Iran was in it as well.

From there I found that a little of Iran's soil near the border with Azerbaijan is in the outernmost part of the asteroid's shadow.

It is obvious that people in central Azerbaijan can see the occultation with no problem (unless there is a bad weather). But what about Iran? Can people from the Azerbaijan-Iran borderline see a good occultation as well?

Well, I am Iranian myself and I don't want to miss this rare opportunity :(

Also, if you can help me to determine the exact UTC time the shadow reaches Azerbaijan-Iran border it will be very appreciated.

With Iran's name labeled


1 Answer 1


The number 10 at the mark across the path means that the occultation is expected to occur there at 1:10 UTC (4:40 Iran time).

For this occultation, the star's apparent angular diameter is somewhat larger than the asteroid's. Between the dot-dashed lines along the middle of the path, the occultation should be annular. An observer there can expect a light curve resembling the example at upper right.

Farther off the centerline, the solid lines indicate where the edge of the penumbra is expected to pass. From there, an observer would see little if any dimming of Betelgeuse. Just outside those, the dashed lines represent a 1σ error estimate. An observer outside those lines will likely see no effect. The curve inside the penumbral band is just 40°N latitude.

The Japanese page also links to an interactive map. Here is another forecast in English.

Other asteroid occultations may be easier to observe from your region. To search for those, IOTA recommends the Windows applications Occult or OccultWatcher.

  • 1
    $\begingroup$ Sighs. Other asteroid occultations in my region are for stars which aren't visible to the naked eye. I saw a forecast of such occultations in the South West Asia. $\endgroup$ Jun 15, 2023 at 18:52
  • $\begingroup$ With an annular occultation I think the star will still shine and no changes are visible through the naked eyes. Am I right? $\endgroup$ Jun 16, 2023 at 0:40
  • $\begingroup$ @SnackExchange In this case ~37% of the star's disk would shine past the asteroid, so it would appear to dim by about 1 magnitude. $\endgroup$
    – Mike G
    Jun 16, 2023 at 2:00
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    $\begingroup$ The chart gives the diameters of the star (48 milli-arcseconds) and asteroid (38 mas). The magnitude drop is only 1.1 magnitude which may not be obvious to an inexperienced observer. Note that the path may be updated in the days before the event, so the path could move into Iran or farther away. $\endgroup$
    – JohnHoltz
    Jun 16, 2023 at 2:37
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    $\begingroup$ @MikeG The Wikipedia article for Leona also lists 5 different amounts for its diameter from 5 different sources. $\endgroup$ Jun 21, 2023 at 3:48

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