Fabrice Mottez


Research director at CNRS / Laboratoire Univers et THéories (LUTH) / Observatoire de Paris.

A theory for the Fast Radio Bursts (FRB)

From the Observatoire de Paris news

Since their discovery in 2007, the fast radio bursts (5 milliseconds) are still very mysterious to astronomers. Several theories have been proposed, involving collisions of stars, but radio signals should be accompanied by emissions at other wavelengths, which are not observed. Two astronomers from the Observatoire de Paris offer another explanation, related to pulsars, and which involves companions in orbit. This model predicts that other radio bursts will be issued by the same given object with a certain periodicity, and could soon be tested. Since the publication of this paper, repeating FRB have been observed, but with no periodicity. Are they triggered by a swarm of pulsar companions ?

Recent academic publication

"Collisionless Plasmas in Astrophysics", Gérard Belmont, Roland Grappin, Fabrice Mottez, Filippo Pantellini, Guy Pelletier, Editions Wiley, ISBN : 978-3-527-41074-3, 422 pages, 2013.

Collisionless Plasmas in Astrophysics examines the unique properties of media without collisions in plasma physics. Experts in this field, the authors present the first book to concentrate on collisionless conditions in plasmas, whether close or not to thermal equilibrium. Filling a void in scientific literature, Collisionless Plasmas in Astrophysics explains the possibilities of modeling such plasmas, using a fluid or a kinetic framework. It also addresses common misconceptions that even professionals may possess, on phenomena such as "collisionless (Landau) damping". Abundant illustrations are given in both space physics and astrophysics.

Scientific research


Research topics

Interaction of pulsar wind and pulsar companions

Pulsar Magnetospheres

Polar auroras

Acceleration processes in the magnetosphere :

Io-Jupiter interaction

Physics of plasmas: a book

Physics of plasmas: Kinetic models of tangential discontinuities

Physics of plasmas: Landau damping revisited (with solutions not given by Landau)

Numerical methods for space plasmas

Turbulence and coherent structures in the magnetosphere :

Instrumentation (modest contributions)


Other publications

Research management

Recent engagements


A course on space plasmas (plasmas spatiaux) , in the Master 2 de Physique des Plasmas et de la Fusion, managed by institutes in Paris and its region.

Public outreach activities


"2012 Scénarios pour une fin du monde" by Didier Jamet and Fabrice Mottez. Ed Belin, 2009.

A scientific answer to recurrent questions about the possible astronomical and geophysical "End of the Word" scenarios. This book was written at the begining of the 2012 frenzy, but it may also be relevant for the next apocalyptic annoncement. Also translated in Portuguese.

French translation of two Mangas about Earth Sciences
""Une aurore, qu'est-ce que c'est ?" et "Qu'est-ce que le champ géomagnétique ?"

Two Japanese mangas, drawn by Hayanon, translated (from English) by Fabrice Mottez. (Projet CAWSES). Click on the image to download the files (11 Mo pdf).

Space Bus Maroc 2016

During three week in october 2016, , a conference room mounted onto a truck, two mini-buses, and a team of about 25 people met the public all accross Moroco. They proposed conferences on astronomy, small workshops about planets, spectroscopy, observations of the sun and of the nightsky with telescopes. Their public : schools from kindergarden to university, teachers, clubs of astronomy, and general public. The Paris Observatory was involved into that project and I participated to the animations from 21 to 29 october, 2016.

Spacebus, Sénégal 2015

March 2015 : the Space Bus organized by l'Association Sénégalaise pour la Promotion de l'Astronomie (ASPA) went across Senegal. They met the general public, schools, students and teacher, with an exhibition, conferences on sciences, astronomy, physical experiments, and observations of the sun and of the night sky. The Paris Observatory was involved into that project, and I participated to the animations during a week.

More public outreach activities

Public conferences about astronomy Themes : polar auroras, neutron stars and pulsars, "end of the world"-related topics (since the rumor about 2012), general introduction to astronomy, to the solar system etc.

A club Leader of a club of astronomy and physics at the Maison des Jeunes et de la Culture de Palaiseau. Created in september 2016. This club, with an introduction to scientific computing and experiments, and I hope soon, astronomical observations, meets a population of entusiastic teenagers.

A series of courses at the Festival d'Astronomie de Haute Maurienne,

France-HOU Hands on Universe L'Univers à portée de main (Hands on Universe) is an outreach program for high school students. It is based on astronomy, to introduce the use of the physics and mathematics and other subjects taught in high school ("collèges" and "lycées" in France). Hand on Universe in an international program.

My contributions : Contribution to an exercice : measurement of the distance of the Small Magellanic cloud with Cepheids, using Oggle telecope data. Workshops in "lycée de l'Essouriau", in the town "les Ulis", devoted to the measurement of distances in the universe, during 3 years. A paper (in French) was published in "l'Astronomie", (journal of the "Société Astronomique de France" SAF), in october 2003.

Public outreach on the Web (pages in french)

  • Une introduction à la physique spatiale.
  • Ciel des Hommes, A more or less regular participation to this Web site dedicated to astronomy. "Ciel des Hommes" includes the french translation of the "Astronomical Picture of the Day"(APOD) , and of "Science at Nasa", a few original papers, and question/answers with our readers.
A few exemples of pages on the Net :

Date: octobre 1999. Last version : aug 21st 2014.