You may already know my astronomy catalog search engine, the DSO. It includes all the catalogs we amateurs use: the Messier, Caldwell, NGC, IC, Arp, SH2, Collinder, Melotte, Abell planetaries, it even grabs the list of exoplanets from a wiki page to always be up to date. But this is not all. It includes some ugly formulae to know about the position of the Sun and the Moon, and do some math based on the geolocation of the user. The DSO however is more like a text mode tool, or an API. It is good to just look up what Messier 51 or NGC 7000 is. Anything more complex requires some heavy wizardry even I don’t master and need to look up in the help I fortunately did write.





