Photometry differential of comets

TL;DR

This paper presents photometric observations of three comets using CCD cameras and filters, analyzing their brightness variations and technical setup.

Contribution

It provides new photometric data and methodology for observing comets with specific CCD configurations and defocus techniques.

Findings

Photometric measurements of three comets obtained.

Use of defocus technique for comet 6P.

Technical details of observational setup provided.

Abstract

Here are presented the results obtained with three comets 73P (Schwassmann Wachmann) B the component B, 6P dArrest and C2008 J1 (Boattini). Comet 73P was observed in April 2006 with a CCD camera Starlight Express SXL8 attached to direct focus of a Newton telescope 250 mm, focal length 1200 mm, while the 6P and C2008 J1 were ever observed by telescope Newtonian but with a CCD camera Atik 16IC to direct focus. To the CCD camera was added a filter photometric Rc (Schuler). For 6P comet has been used a defocus of 14 pixels, meaning that the central false nucleus has defocused a FWHM of 14 pixels. The technical data of the tools used are shown in Tables 1 and 2.