The NEOWISE reactivated mission obtains observations of comets that allow for the detection of CO or CO2 emission line signal and characterization of the comet dust production using the techniques applied in Bauer et al. (2015) and Bauer et al. (2021). NEOWISE has observed four comets, 7P/Pons–Winnecke, 108P/Ciffreo, 125P/Spacewatch, and 96P/ Machholz 1, all of which had CN production rates of less than 5 × 1023 molecules per second within 2 au from the sun as noted in Cochran et al. (2012). In the NEOWISE data we detected signals in excess of the dust in the 4.6μm channel attributable to the presence of CO, or more likely, CO2 emission while three of the four comets were between 1.6 and 2.0 au. In the majority of cases the infrared excess corresponded to production rates of CO2 in excess of 1 × 1025, or 1 × 1026 of CO, molecules per second. 108P/Ciffreo exhibited “hyperactive” levels of activity near perihelion, while 96P/Machholz exhibited no detectable coma.
References: Bauer, J. M., Stevenson, R., Kramer, E., et al. 2015, ApJ, 814, 85. Bauer, J. M., Gicquel, A., Kramer, E., & Meech, K. J.2021, PSJ, 2, 34. Cochran, A. L., Barker, E. S., & Gray, C. L. 2012, Icarus, 218, 144.