Virtual Messier is an interface to the extensive collection of information in the SEDS Messier Object Database. Rather than being a simple table or catalogue, Virtual Messier is a hypertext star atlas: select a Messier object from the appropriate star chart, and Virtual Messier will hunt down the SEDS Database page corresponding to that object, which includes photographs, observing information, historical information, etc.

Most Messier objects on the atlas charts are clickable: click them, and Virtual Messier will fetch the relevant SEDS Messier Database page. Objects extremely close to the edge of a chart may not be mapped. The charts overlap enough that all objects are mapped at least once.

The main sky charts all have fields of view of about 60x40 degrees, and are centered on the coordinates given in the "Atlas Charts" section list. A few star charts are so clogged with Messier objects, or have objects that are so close to each other (e.g., M31/M32/M110), that the regular star chart scale of 60x40 degrees isn't helpful. In these cases, clicking on the Messier objects brings up an enlarged region of the sky, rather than a SEDS entry. These enlarged sky regions are also directly selectable from the "Atlas Charts" list.

Some "Messier objects" are disputed or controversial. The Messier Catalogue used by both SEDS and the program I used to generate the charts does the following:

1. assigns M102 to NGC 5866
2. assigns M40 to the double star Winnecke 4
3. uses the "modern" additions M104 through M110

Atlas Charts

Note: The information that appears when choosing a Messier object is from the SEDS Messier database, not Virtual Messier or the Astronomy Nexus.