There are three kinds of maps on this site.

To view the full details, you can use this map system to zoom and pan around the map.

There are two maps which attempt to summarise the data in one image. You can view the overview map, which shows most of the objects on the main galaxy map with the exception of some smaller star clusters and a few objects on the other side of the galaxy. It also shows the main clouds of non-ionised atomic hydrogen gas in the region. You can also view the fantasy map, to see the major structures in our area of the Milky Way in more familiar planetary terms as gulfs, bays, straits, and islands.

A number of people have asked me to provide maps that fall between these two types of maps - something that provides a wider view than the 360x360 images in the zoomable map system but more detail than the overview maps. To this end I've provided 1280x1024 detail maps that show the galaxy map objects in 22 locations around our galactic region. You can view these maps by clicking on the index image below. These detail maps also show the main clouds of non-ionised atomic hydrogen gas in that region.

More on the maps

The maps on this site do not cover the full Milky Way. Very little data is available on the half of the galaxy on the far side of the galactic nucleus, and even on our side of the galaxy, information on objects located more than about 10 thousand parsecs (about 30 thousand light-years) from the Sun is almost non-existent. I've shown the area of the Milky Way covered by this site in the image on the right, which is derived from an artist's conception of the Milky Way released by NASA.

The galaxy maps show the estimated distances of more than 5000 bright stars. Even the dimmest of these is more than 1200 times brighter than our Sun, and the brightest of all are more than a million times brighter than the Sun. The detail maps place yellow-green labels next to the great "beacon" stars with absolute bolometric magnitudes less than -9.5. There are about 170 such stars in the Galaxy Map database and all of them are more than 600 thousand times brighter than our Sun. The size of the star is relative to its bolometric magnitude (brightness) and the colour of the star is determined by its spectral type (temperature).

In addition to the brightest stars, the maps show the locations of all known star clusters with distance estimates.

As described in the Sources section, the maps also include nebulae from numerous databases. All of these were originally believed to be HII regions, but subsequent research has shown than some are in fact supernova remnants, planetary nebulae, reflection nebulae, or more exotic objects. Nebulae are shown as red spheres. Also shown on the map are several thousand molecular clouds - vast cold regions of dust and gas that are the birth places of most stars. Molecular clouds are shown as green spheres.

You can hover your mouse over each object on the maps (whether labeled or not) to get information about that object, and click on the object to see what additional information is available.

The NASA artist's conceptual image of the Milky Way is not intended to be accurate in any detail, and in fact overlaying the data from this site on the NASA image reveals many discrepancies as you can see in the image on the left (as well as in this more detailed image here). As just one example, the area of the very bright Cygnus X region appears as an inter-arm void on the NASA image. Nevertheless, it gives a general sense of roughly where major objects on the map would appear on a traditional model of the Milky Way. (If anyone reading this has the time and artistic skills to produce a revised version of the NASA conceptual image, I'd love to hear from you. Please leave a comment on my blog).

Detail map index

You can click the image map below to view any of the 22 detail maps.