No dia 23 de abril de 2025 (quarta-feira), às 18h00, acolheremos mais uma edição das AstroTalks, uma iniciativa da SAC - Secção de Astronomia, Astrofísica e Astronáutica da Associação Académica de Coimbra e OGAUC - Observatório Geofísico e Astronómico da Universidade de Coimbra.
O Professor Chad Trujillo (Associate Professor, Department of Astronomy and Planetary Science, Northern Arizona University - Flagstaff, Arizona, USA) irá falar-nos sobre "Active Asteroids, Extremely Distant Trans-Neptunians and Planet X".
Sobre a palestra:
I'm currently working on two independent research projects, the most recent being a search for active asteroids among freely available archival Dark Energy Camera (DECam) data collected from the 4m Cerro Tololo Blanco telescope in Chile. Most of the main belt asteroid population has been serendipitously imaged by DECam, however, nobody has examined the images. We have an ongoing Citizen Science project at activeasteroids.net where we have extracted millions of thumbnail images of all minor planets in the public DECam dataset and asked tens of thousands of volunteers to examine the images to look for comet-like activity among the main belt asteroids. To date, we have identified comet-like activity from over a dozen objects that was previously unrecognized. The known active asteroids, although about 50 in number, are very interesting, as about half of them are suspected to be driven by water ice like the comets are. This suggests that there could be an as-yet-unidentified reservoir of water ice hidden in the main asteroid belt which has implications for the solar system's formation as well as future space travel.
The other project I have been working on is a survey of the most distant parts of the solar system. The trans-Neptunian belt (the Kuiper Belt) is fairly well-studied and its history and dynamics are controlled by Neptune at 30 au. However, further out, the Extreme trans-Neptunian Objects (ETNOs) have eccentric orbits that carry them out to 1,000 au or more with closest approach beyond Neptune's gravitational influence. There are only about a dozen ETNOs and their origin is a mystery but sheds some light on the solar system's formation and hints at the possibility that there could be an undiscovered super-Earth mass planet in our solar system beyond 100 au.