Question

why is the kilometre not used to measure distances between stars?​

Answer 1

Answer:

Simply because astronomical distances are so great that the km is too small of a unit to represent those distances in a practical way.

Answer 2

Answer:

It would be very difficult because stars are not located very close rather they are at a very far distance, so the unit which is used to measure the distance is light years .

1 light year = 9.461 × 1012 kilometres

so you can definitely understand it would be difficult to do calculations on a large scale and make calculation quite difficult to do