Bryce Bolin: The color properties of Neptunian Trojans and giant Oort cloud comet C/2014 UN271

Tuesday, 20 February 2024 4 p.m. — 5 p.m. MST

Gemini North Hilo Base Facility | 670 N A’ohoku Place Hilo, Hawaii, 96720, USA

Gemini North Talks
Bryce Bolin (NASA Goddard Space Flight Center)

BryceBolin Science

The colors of Neptunian Trojans: Neptunian Trojans (NTs) are trans-Neptunian objects in 1:1 mean-motion resonance with Neptune and are thought to have been captured from the original trans-Neptunian disk into co-orbital resonance with the ice giant during its outward migration. It is possible, that the color distribution of NTs tests the location of any color transition zones between the inner and outer disk. In support of this possible test, we obtained g, r, and i-band observations of 18 NTs, finding that the NT color distribution is statistically distinct from other trans-Neptunian objects. The observed distribution of NT colors suggests that the protoplanetary disk color transition zone was interior to ~30 au.

The physical properties of 140 km Oort cloud comet C/2014 UN271: Comets are pristine remnants of the original planetesimals that formed beyond the gas giants. The Oort Cloud comet C/2014 UN271, hereafter UN271, is ~140 km in diameter, large enough that it could be an intact example of a planetesimal that accreted in the protoplanetary disk. It is on its first inbound into the planetary region providing the rare opportunity to study the physical and volatile properties of an original planetesimal. We present Gemini S/GMOS-S and JWST/NIRSpec observations of UN271 taken in 2021 and 2022, covering 0.4-5.2 microns. Our observations provide constraints on the comet's dust and volatile contents (H2O, CO2, and CO), its activity-driving mechanism, and the formation of the planetesimals and Oort Cloud.

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