Call for Observation
Transatlantic Occultation by TNO (84522) 2002 TC302 in Europe and North America on November 11th 2021
The minor planet (84522) 2002 TC302 is a large TNO and was considered to be a dwarf planet. It is orbiting the sun in a ratio of 5:2 with respect to Neptune. But the true diameter of the object is still a mystery. Estimates after observations with the Spitzer Space Telescope gave a diameter of ~1145 km. This would have made the TNO one of largest possible dwarft planets. Later observations with Herschel Space Telescope shrank the estimated diameter to ~584 km. This value was confirmed by the observations of a stellar occultation of a 15.7 mag star in January 2018 in Europe .
The difference between the measured diameters could give an indication of a satellite orbiting the TNO very closely. If this satellite is a quite large object the position of the TNO would oscillate around its barycentre by several milliarcseconds. This would have a major influence on the predicted path for the upcoming occultation. Path shifts are highly possible!
Details about 2002 TC302 including the satellite hypothesis and the stellar occultation in 2018 can be found in a paper by J. L. Ortiz et al. .
The Stellar Occultation on 2021 Nov 11
UCAC4 616-007599 on 2021 Nov 11, 02:50 - 02:58 UT
RA: 02 41 17.3086 DE: +33 00 00.155
(Astrometric position with proper motion and parallax to date of event)
Star V mag 11.7 B mag 12.3
In the moment of an occultation the combined light of asteroid and star will drop by 8.7 mag (v), 8.6 mag (r).
The shadow will cross Turkey, Bulgaria, Greece, Albania, , Italy, Macedonia, Montenegro, Serbia, Bosna and Herzegovina, Croatia, Slovenia, Romania, Hungary, Austria, Germany, Liechtenstein, Switzerland, Luxembourg, Belgium, France, UK and Ireland.
The 1-simga uncertainties cover whole Europe down to central Spain!
Occultwatcher Cloud Path Maps for Europe and North America
Based on the Prediction of 2021 Oct 10 with Data from JPL Horizons and Gaia EDR3
About the map:
OW Cloud path map for Europe. The green line is the centre line, the blue lines show the path limits, and the red lines the 1-sigma-limit. The occultation will occur between the two red lines with a probability of 68 %. (Map data: © 2021 GeoBasis-DE/BKG, (©2009), Google, Inst. Geogr. Nacional)
After passing the Atlantic the shadow will pass eastern Canada, the US from northeast to the southwest and the northeast of Mexico.
About the map:
OW Cloud path map for North America. The green line is the centre line, the blue lines show the path limits, and the red lines the 1-sigma-limit. The occultation will occur between the two red lines with a probability of 68 %. (Map data: © 2021 Google, INEGI)
Please use the predictions in OW Cloud for zooming into the maps and for information about the predicted time of event. (Click on map in OW Cloud) .
Alternate Prediction by the Lucky Star Team
The Lucky Star Team in Paris has published an alternate prediction on 2021 Aug 29 with the path located more to the south . We expecting an update in the upcoming weeks.
About the map:
Path map for the stellar occultation by (84522) 2002 TC302 on 2021 Nov 11 predicted by the Lucky Star team on 2021 Aug 29. The blue lines show the path and the dashed red lines the 1-sigma-limit. The occultation will occur between the two dashed red lines with a probability of 68 %. (Map data: © OpenStreetMap, Lucky Star)
Good luck with your observation
Oliver Klös and Wolfgang Beisker
IOTA/ES, Public Relations
For reporting results or other remarks and questions please use either Planoccult or the EMAIL firstname.lastname@example.org
Charts to find 2002TC302
Generated with XEPHEM you find charts for finding 2002TC302 as downloads in pdf:
20 min field
_1 deg field
11 deg field
75 deg field
 J. L. Ortiz et al. The large trans-Neptunian object 2002 TC302 from combined stellar occultation, photometry, and astrometry data
Prediction in OW Cloud:
Prediction of the Lucky Star Team:
Link to Steve Preston’s prediction with path ccordinates: