Amir Siraj (Harvard)

Amir Siraj (Harvard)
Tuesday, November 2, 2021 - 12:30pm
Hybrid - 54-915 and Zoom

The New Astronomical Frontier of Interstellar Objects

The upcoming commencement of the Vera C. Rubin Observatory’s Legacy Survey of Space of Time (LSST) will increase the discovery rate of interstellar objects (ISOs). ‘Oumuamua and Borisov were the first two ISOs confirmed in the Solar system, although the first interstellar meteor may have been discovered earlier. I will first review the characteristics of `Oumuamua and Borisov and then discuss generalized properties of ISOs. I will compare the expected abundance of ISOs to that of objects in the Oort cloud and draw conclusions about the mass budget per star that is required to produce ISOs. Next, I will investigate the possibility of ISOs being captured into bound orbits in the solar system, both from the solar birth cluster and from the field, and I will highlight the potential of ISOs to facilitate the transfer of material between planetary systems. Furthermore, I will consider observational signatures of ISOs colliding with the Earth, the Moon, and neutron stars, as well as the possibility of differentiating ISOs from solar system objects in stellar occultation surveys. Finally, I will explore advantages that the imminent advent of LSST will afford the field of ISO studies, including large-number statistics that will reveal the origins of ISOs and discoveries of rare ISOs providing insights into exotic astrophysical phenomena.

About this Series:

he MIT Planetary Lunch Seminar [PLS] is a weekly seminar series organized within the EAPS department. Colloquia topics span the range of research interests of the department's planetary sciences research program. The seminars usually take place on Tuesdays from 12:30-1:30 pm unless otherwise noted (term-time only). Speakers include members of the MIT community and visitors. Talks are intended to appeal to graduate students, postdocs, research scientists, and faculty with a background in planetary science. Contact: