Why Did the Death Star Have to Orbit Yavin?
Why didn’t the Death Star come out of hyperspace closer to Yavin Four? Because hyperspace doesn’t work quite like that. You don’t get to choose exactly where in a star system you come out of hyperspace. The safest way to travel at light speed is through the use of known and charted hyperspace lanes. Like Han explains earlier in the movie, precise calculations are needed to make sure a vessel doesn’t fly through a star or run into some other interstellar object. So the Imperials took the Death Star as close as they safely could to Yavin 4. It’s possible they could have attempted a microjump, basically a very fast and short trip through hyperspace, but even that kind of travel could send a ship across thousands of kilometers. It’s possible microjumping something as big as the Death Star would have been even more difficult. Grand Moff Tarkin probably thought it was just as easy to wait the thirty minutes to orbit Yavin.