Presentation #210.17 in the session “Comets”.
The NEOWISE mission, making use of the Wide-field Infrared Survey Explorer (WISE) spacecraft, has continued to perform all-sky surveys in its 3.4- and 4.6-micron bands, as it has done since 2013 (Wright et al. 2010, Mainzer et al. 2010, 2014). As of mid-2021 it has detected hundreds of comets, many at multiple epochs. In addition to the major goals of discovering and characterizing Near-Earth Objects (NEOs) NEOWISE was able to constrain the dust, the nucleus size, and the carbon monoxide (CO) and carbon dioxide (CO2) production in comets. The 4.6 μm channel allows observation of the strong cometary emission lines of CO (4.67 μm) and CO2 (4.23 μm). CO and CO2 are hypervolatile ices that make up roughly 10% of the comet’s total ice content, so they are likely primary drivers of cometary activity beyond ~3 au. Thus, measurements of their production vs. time, vs. heliocentric distance, and vs. the dust production rate, which NEOWISE simultaneously give us, can give insight into cometary activity and cometary origins. Since detection of CO2 from Earth is impossible due to the telluric contamination, observation by spacecraft as NEOWISE can give us valuable measurements. We will focus on comets observed by NEOWISE in 2014 (NEOWISE — Year 1). We will present the dust production (Afr) and CO+CO2 production rates. We will investigate the relationship between dust production and the gas production rate for these species, as well as their dependence on heliocentric distance. Finally, we will compare result from short-period and long-periods comets. This work is a follow-up to Rosser et al. 2018 and Bauer et al. 2015, and we will build on some of the trends seen there.