MU69 (also named Ultima Thule) is a transneptunian object of our solar system (i.e. an icy body with an orbit beyond that of Pluto). This object will be visited in 2019 by the “New Horizons” spacecraft, who has recently provided to planetary scientists spectacular images about Pluto. The diameter of this object is between 30 and 45 km.

It is possible to determine more precisely the shape of this object by observing stellar occultations (when the object passes between a star and an observer on the Earth). Such observations have been done in 2017.

The next useful occultation will be on August 4, 2018, with a trajectory that passes through Senegal and Mali ! This is a chance for west African astronomers to contribute to  the NASA mission. This occultation will take place before sunrise (around 4 am) and the occult star will be of magnitude 13. The duration of the occultation is (only) less than 1 s.

NASA plans to send up to 22 portable telescopes and a team of around 50 people, lead by Marc Buie, to observe the Ultima Thule Occultation Event in Senegal and additional systems to Colombia. The observations are organized with the support of the Ministry of Education, Research and Innovation of Senegal. 7 french astronomers will also contribute to the observation campaign with financial support from the french national space agency, CNES, and from the ERC projet “Lucky Star” led by Bruno SICARDY):
– Romuald BALLET (Amateur Astronomer)
– David BARATOUX (Planetary Scientist, French National Research Institute for Sustainable Development, Toulouse)
– Cyril BIRNBAUM (Specialist of stellar occultation, head of the Planetarium of the “Cites des Sciences, Paris).
– François COLAS (Astronomer, lead of the FRIPON network for meteor observations, Observatory of Paris)
– Jean-Luc DAUVERGNE (Science writer, and Journalist at Ciel & Espace)
– Josselin DESMARS (Specialist of stellar occultation, Observatory of Paris)
– Thierry LEGAULT (Amateur Astronomer, Astrophographer)
– Olivier MOUSIS (Planetary Scientist, Université Aix-Marseille)

22 Senegalese students or scientists will also have a unique opportunity to join the NASA team ! Some of them are members of the Senegalese Association for the Promotion of Astronomy. Salma SYLLA, first Ph.D. student in Astrophysics at the University Cheikh Anta Diop (at the moment in Belgium for research and training) will also participate to the observations with the financial support from the french association Uranoscope de France.

Conferences and public events will be organized by Senegalese, American and French astronomers before and after the 4th of August. Stay tuned on http://africapss.org and AFIPS Facebook page !