List of archive data of rectangular X,Y positions

These positions are useful to plot charts or determine cross-identifications. They have been used extensively in the database, but so far not made publicly available.
This archive allows to plot the charts and retrieve the original files.

The X,Y positions have been computed with respect to a central star (x = X - Xc) to make it easier to use. The number of the star selected as central object is given in the column Center and the original coordinates are given in the columns Xc and Yc.

If the column Center is empty, it means that the X,Y positions have been measured on the plate found in the reference quoted.
Measurements have always been refered to a central object.

The magnitudes indicated in the file are normally the Johnson V magnitude. But it may also be mpg or G from RGU, depending on the original data.
The column Mag precises which kind of magnitudes is used in each file.

The link under the file name (for example mathews.xy) plots the map. The maps are active, one can click on the star to get their identifications.
The link under the X,Y displays the data or retrieves the data by http.

NGC clusters

IC clusters

Anon clusters