Planetary and exoplanetary Astronomy Lunch Seminar (PALS) for 2021-10-25

Series: Planetary and exoplanetary Astronomy Lunch Seminar (PALS)
Date: Monday 25-Oct-2021
Time: 11:15-12:15
Location: Online via Zoom (link sent out to the PALS distribution list prior to the talk)
Speaker: Ariel Graykowski (UCLA)
Title: Investigation of the Fragments of Split Comet 73P

I will talk about cometary fragmentation in general as well as a case study of split comet 73P/Schwassmann-Wachmann 3. Fragmentation mechanisms remain somewhat mysterious with potential mechanisms including tidal forces, rotational instability, thermal pressure, outgassing pressure, and impacts. Comet 73P has been observed to fragment on several occasions, however the cause of its fragmentation is poorly understood. We analyzed unpublished archival Hubble Space Telescope data in order to understand its fragmentation mechanism. For example, the literature presents a wide range of measured rotational periods for the nucleus of the comet, 73P-C, some that suggest the nucleus might have split due to rotational instability. However, we find the most likely value of the rotation period to be at least ~10.4 hours, much longer than the critical period for rotational instability for any reasonable nucleus density. I will also present our current work on fragments 73P-B and G, which show 100s of mini fragments within their comae. We analyze various properties of these fragments such as their speed on the plane of the sky and their size and frequency distributions in order to further constrain potential fragmentation mechanisms.

For further information contact PALS coordinators Drs. Quanzhi Ye (qye@umd.edu) and Matej Malik (malik@umd.edu).

SPECIAL ACCOMMODATIONS:

Special accommodations for individuals with disabilities can be made by calling (301) 405-3001. It would be appreciated if we are notified at least one week in advance.

DIRECTIONS AND PARKING

Directions and information about parking can be found here.

This page was automatically generated on: 19-Oct-2021.