# Fringes' Impacts to Astrometry and Photometry of Stars

## TL;DR

This study investigates how fringes in CCD images affect star measurements and demonstrates that a new fringe removal technique significantly improves astrometric and photometric accuracy, especially for faint stars.

## Contribution

The paper applies a novel fringe removal method to CCD frames and evaluates its effectiveness in enhancing star measurement precision.

## Key findings

- Fringe removal improves astrometric accuracy.
- Photometric precision is significantly enhanced.
- Faint stars benefit most from fringe correction.

## Abstract

Fringes often appear in a CCD frame, especially when a thin CCD chip and a R or I filter is used. 88 CCD frames of the two open clusters NGC 2324 and NGC 1664 with a Johnson I filter taken from the 2.4-m telescope at Yunnan Observatory are used to study the fringes' impacts to the astrometry and photometry of stars. A novel technique proposed by Snodgrass & Carry is applied to remove the fringes in each CCD frame. And an appraisal of this technique is performed to estimate fringes' effects on astrometry and photometry of stars. Our results show that the astrometric and photometric precisions of stars can be improved effectively after the removal of fringes, especially for faint stars.