The activity of comet C/2014 E2 (Jacques) from pre and post-perihelion images

Abstract

We present ground-based optical and infrared imaging observations of long period comet C/2014 E2 (Jacques) before and after its perihelion passage. The aim of this work is to characterize the activity of the comet C/2014 E2 (Jacques) in its pre- and post-perihelion stages. Both from the morphological and photometric point of view, as well as its gas production (CO or CO2). We observed the comet with the 2.15 ​m telescope at CASLEO whit R broadband. For the analysis of the inner coma of the comet we used a series of enhancement filters in order to find dust structures. To estimate the dust production of the comet we made photometric measurements to calculate the Afρ parameter. To estimate the gas production we used NEOWISE infrared images of the comet. It was possible to identify two jet-like structures coming out from the nuclear region of the comet, one in the sun-ward direction (which is most likely the dust tail) and the other which probably is due to ejected dust from an active region in the nucleus. These two features were observed in pre- and post-perihelion observations. The A(0°)fρ values calculated for comet Jacques (in cm) were: 909 ​± ​47, 1014 ​± ​21, 706 ​± ​23 for pre-perihelion at ∼1.27au and 450 ​± ​21, 444 ​± ​20, 411 ​± ​18 for post-perihelion at ∼1.64au. The values derived for QCO (in molecules s−1) were: <5.24×1027,<5.92×1028,<1.41×1028. While for QCO2 (in molecules s−1) were: <4.62×1026,<5.21×1027,<1.24×1027. These values are upper limits since we can't discern between CO and CO2 emission.