The estimation of interstellar extinction is essential for all fields of astronomy, from stellar studies where we want to know the extinction towards a given object from its coordinates and distances (3D Models), to extragalactic astronomy field. In the latter case it is necessary to identify the contribution of the extinction of our Galaxy along the line of sight. In the last three decades many models and maps have been developed to describe the dust distribution in our Galaxy.

Our VO-Service called GALExtin estimates interstellar extinction based on both 3D models/maps and 2D maps available. The users only need to provide a list with coordinates (and distances) and to choose the model/map; GALExtin will then provide an output list with extinction determination. One of the main advantages of our VO-Service is ability to have available several models and maps developed in different languages (that use specific file annotations, some of them large ASCII tables), all wrapped in a unique tool.

For usage guidelines, acknowledgements and other issues, please see the page FAQs.


The simulations made by the users are at your risk, as well as the provided input files. Concerning the GALExtin estimates of Galactic interstellar extinction, Dr Eduardo Amôres has checked its consistency by comparing the results obtained with it with those obtained with the same programs running outside the GALExtin server. If you find any problem, please let us know (

Some of the others on-line tools

We want to emphasize the great work done by other authors who have developed tools that also provide interstellar extinction estimates. We certainly do not intend to force GALExtin estimates over their extinction values. Our main objective is to provide a collaborative VO-Service.

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