Constraining the Physical Properties and Activity of 3 Unique Comets: 2009 MS9, C/2016 VZ18, and C/2016 R2
Abstract
We will report on an investigation of the physical characteristics of three unique, dynamically different small bodies: 2009 MS9, C/2016 VZ18 (PANSTARRS), and C2016 R2 (PANSTARRS), in order to understand their origins, evolution, and roles in solar system growth. We characterize each comet's physical properties and investigate potential ice sublimation using several methods including analysis of dust and coma dynamics with composite images, quantifying changes in photometry with sublimation and thermodynamic models, and calculating spectral reflectivity to determine surface material composition and likely asteroid class. 2009 MS9 has q = 10.99 au, Q =707.17 au and passed perihelion in Feb. 2013. Broadband photometry suggested that it might be brighter after perihelion than would be expected from geometry and rotation alone. Data from NEOWISE estimates a radius of 11.5 km for 2009 MS9. We did not detect any significant activity and can place strong upper limits on the amount of outgassing. With q = 0.91 au and Q = 388.3, C/2016 VZ18 is classified as a long period comet. However at the time of its discovery it was inactive (r=5.8 au) and did not develop noticeable coma until it was inside 1 au. We thus considered it a Manx candidate, or a long period comet with no or with unusually low sublimation activity. Manxes have the potential to help us constrain solar system formation models. We will present a thermal model of the activity of C/2016 VZ18 around 1 au, which suggests that the volatiles were at some depth beneath the surface. C/2016 R2 is a long period comet, apparently rich in CO or CO2. Our models of the activity for this comet can be used to help constrain the nucleus size and relative abundances of H2O, CO and CO2. We will report on the results of this analysis and discuss how it can be used to provide insight about the distribution of volatiles in the early solar system. This work is supported by NSF grants AST1413736 and AST1617015.
- Publication:
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AAS/Division for Planetary Sciences Meeting Abstracts #50
- Pub Date:
- October 2018
- Bibcode:
- 2018DPS....5020406B