Direct measurements of the Galactic acceleration

Sukanya Chakrabarti
Rochester Institute of Technology; Member, School of Natural Sciences
September 24, 2020
I will discuss recent work that lays out two methods to obtain direct measurements of the Galactic acceleration. First, I will review our recent work in using high precision spectrographs to measure the Galactic acceleration. These measurements can be used to determine the total density from the Poisson equation, and given an accounting of the baryon budget, the dark matter density. Secondly, I will discuss ongoing work to use pulsar timing data to measure the local Galactic acceleration, which thereby gives a direct measure of the Oort limit.

Two Freaks and a Conundrum

David Jewitt
September 22, 2020
In the solar system as elsewhere, we learn most from the unexpected. I will describe three recent observational projects challenging existing ideas about solar system objects, and provoking new ones. The freaks are an interstellar object (‘Oumuamua) and a long-period comet (C/2017 K2), active far beyond Uranus. The conundrum concerns the origin of the Trojans of Neptune in the context of planetary migration.