# Transformation of Pan-STARRS1 gri to Stetson BVRI magnitudes. Photometry of small bodies observations

## TL;DR

This paper develops and discusses transformations between Pan-STARRS1 grizyw and Stetson BVRI photometric systems, demonstrating an algorithm for data calibration and asteroid magnitude determination.

## Contribution

It introduces a new transformation method between Pan-STARRS1 and Stetson photometric systems and presents an algorithm for data reduction and calibration.

## Key findings

- Successful transformation equations between systems
- Demonstrated calibration algorithm on asteroid data
- Improved accuracy in small body photometry

## Abstract

The UBVRI broad band photometric system is widely used in CCD astronomy. There are a lot of sets of standard stars for this photometric system, the Landolt's and Stetson's catalogues being the most precise and reliable. Another photometric system, recently considerably spread in CCD observations is ugriz, which originates from the Sloan Digital Sky Survey (SDSS) and has now many variations based on its 5 broad-band filters. One of the photometric systems based on it is The Panoramic Survey Telescope and Rapid Response System (Pan-STARRS). In this paper we compare the BVRI magnitudes in the Stetson catalogue of standard stars with the magnitudes of the corresponding stars in the Pan-STARRS1 (PS1) grizyw catalogue. Transformations between these two systems are presented and discussed. An algorithm for data reduction and calibration is developed and its functionality is demonstrated in the magnitude determination of an asteroid.