Coordinates and 2MASS and OGLE identifications for all stars in Arp's 1965 finding chart for Baade's Window

TL;DR

This paper provides precise coordinates and identifications from 2MASS and OGLE for all stars in Arp's 1965 Baade's Window chart, enhancing historical star data with modern surveys.

Contribution

It offers the first comprehensive cross-identification and coordinate catalog for stars in Arp's Baade's Window chart using modern infrared and optical surveys.

Findings

Coordinates for all stars in Arp's chart are provided.

Two stars are newly identified that were missing in the original chart.

Enhanced star data facilitates future astronomical research in Baade's Window.

Abstract

Aims: We seek to provide 2MASS and OGLE identifications and coordinates for all stars in the finding chart published by Arp\,(1965). This chart covers the low extinction area around NGC 6522, also known as Baade's window, at coordinates (l,b)=(1.02,-3.92). Methods: A cross correlation, using numerical techniques, was performed between a scan of the original finding chart from Arp (1965) and 2MASS and OGLE-II images and stellar coordinates. Results: We provide coordinates for all stars in Arp's finding chart and 2MASS and OGLE identifications wherever possible. Two identifications in quadrant II do not appear in the original finding chart.