Due to numerous new discoveries of open star clusters in the last two decades, astronomers need an easy-touse
resource to get visual information on the relative position of clusters in the sky. Therefore we propose a new atlas
of open star clusters. It is based on a table compiled from the largest modern cluster catalogues. The atlas shows the
positions and sizes of 3291 clusters and associations, and consists of two parts. The first contains 108 maps of 12 by 12
degrees with an overlapping of 2 degrees in three strips along the Galactic equator. The second one is an online web
application, which shows a square field of an arbitrary size, either in equatorial coordinates or in galactic coordinates
by request. The atlas is proposed for the sampling of clusters and cluster stars for further investigation. Another use is
the identification of clusters among overdensities in stellar density maps or among stellar groups in images of the sky.
The online atlas is accessible at the address http://astro.ins.urfu.ru/atlas. You will need to register in order to get an access. Choice of an object by its name had changed as compared to the paper for greater convenience. You can enter either the full cluster name (NGC 1912, Collinder 31), or the shortened name in accordance with Table 2 of the paper, but without the underlined symbol. Please send your remarks to e-mail address. We would be very grateful for your response and for your reference to the atlas paper if the atlas will help in your work. We plan to supplement the atlas with new data on clusters regularly.