I think what you are looking for is the intermediate and then advanced discovery scanners - they do the same job as the basic discovery scanner namely find out what objects are in a system only at greater distances. The detailed surface scanner comes in the usual classes and is used when you fly towards the objects found by the discovery scanner when it automatically scans them to find out what they are.
So you fly into a system and without doing anything may get "newly discovered astronomical object" and the star appears. If you have the discovery scanner on your second fire group you hold the trigger for 30 seconds and get a big "boop" noise telling you it has finished and you may then have other "newly discovered astronomical objects". You then point your ship at each object (including the star) and target it and the detailed surface scanner will start and then tell you what it is - class M yellow or whatever for stars, gas giant, rocky etc for planets. Stars can be scanned from a considerable distance, large planets from around 100ls and small moons from 10ls - so to properly scan a system you do need to fly towards each object.