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Occultation by (252) Clementina across Europe, 2023 Mar 17

Asteroid (252) Clementina (14.9 mag) will occult an 14.2 mag star around 02:52 UT on 2023 March 17. A good path coverage of this event if highly desired to confirm an unusually observation of a stellar occultation by this asteroid made in February 2022.

The Target Star

UCAC4 403-056470 RA: 13 05 13.42 DE: -09 35 30.53 (Astrometric position with proper motion and parallax to date of event) Vmag star 14.21 Constellation: Virgo

The Asteroid

(252) Clementina is a main-belt astetoid with a diameter of ~65 km. At the time of the event on March 17 the asteroid has a distance of 2.4 au from Earth and its apparent motion across the sky is 25.2 arcsec/h. 3D-models of the asteroid show an irregular, diamond-like shape [1]. Occultations by the minor planet were observed four times. The best result was recorded on 2022 January 17 with three chords, two of theses chords were positive [2].

The Occultation by (252) Clementina on 2023 Mar 17

The path of (252) Clementina will cross Turkey, Bulgaria, Romania, Serbia, Hungary, Slovakia, Czech Republic, Poland, Germany, Denmark, Sweden and Norway.

Expected maximum duration: 5.3 s
Drop of magnitude: 1.14 mag

Figure 1. The path prediction was made with Dave Herald’s Occult 4 and data from JPL Horizons and Gaia EDR3 on 2023 March 4. The occultation will occur somewhere between the dashed lines of the 1-sigma error limits with a probability of 68 %. (IOTA/ES)

Details, times and path maps with zoom function in Occult Watcher Cloud:
Mobile observers should check the prediction in Occult Watcher Cloud for latest path updates a few days before the date of event.

The Occultation Observation on 2022 February 8.

The light curve recorded by Gregor Krannich (IOTA/ES) showed two successively drops with an increase to the full combined light between these drops (duration 0.7 s). This could be caused by a concave profile of the asteroid. Unfortunately Gregor Krannich was the only observer of the this occultation. His observation could be confirmed on March 17 with a good path coverage by multiple stations.
For details of the February 2022 observation by Gregor Krannich read his observation report in JOA 2023-01, page 3-10 Good luck with your observation,

Oliver Klös
Public Relations


[1] Frieger, G., 3D Asteroid Catalogue
[2] Herald, D., Occult - Asteroid observation database, 2023 Mar 4