Résumé / Abstract Seminaire_IAP
« Exocomets: 35 Years of Discoveries »

Alain Lecavelier des Etangs
Institut d'Astrophysique de Paris (Paris, France)

Transiting extrasolar comets have been observed for 35 years. The gas component of the evaporating comets has been first revealed using spectroscopy. Along the years, a very large number of observed lines provided information on the physical state of the gas. Statistical studies of hundreds of exocomets transiting the young star Beta Pictoris showed the presence of two different orbital families pointing toward two different origins of these small bodies.

Recently, the photometric accuracy of Kepler and TESS allowed to detect the dust tails of the transiting exocomets. The observed transit light curves look very similar to what was predicted 20 years ago. Using TESS photometry, we discovered 30 exocomets transiting Beta Pictoris and derived the comets nuclei size distribution. The observed size distribution is strikingly similar to the one of the comets and asteroids in the Solar system. With a power law index of -3.5, this shows the importance of collisions and fragmentations in the late stages of the planetary formation.


vendredi 16 septembre 2022 - 11:00
Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris
Page web du séminaire / Seminar's webpage