The most common and most likely answer to this crossword clue is the 6 letter word GALAXY
I've seen this crossword clue in The Daily Telegraph
G
A
L
A
X
Y
More clues leading to the result GALAXY
- Many stars possibly camp outside American airport
- A lot of stars as well as unknowns supporting festivity
- Stars laid-back in carefree surroundings
- Two unknowns supporting sporting occasion’s collection of stars
- Show axes stars
- Large plane happy to circle Californian airport
- Many stars are not straight about Hollywood’s nearest airport
- Party axes stars here
- … celebration and kiss beside unknown number of stars
- Careless, entertained by happy host
Buddy explains!

The straight part
We know that "It’s star-studded" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case it’s star-studded = galaxy.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does GALAXY mean?
GALAXY noun- The Milky Way; the apparent band of concentrated stars which appears in the night sky over earth.
- Any of the collections of many millions or billions of stars, galactic dust, black holes, etc. existing as independent and coherent systems, of which there are billions in the known universe.
- Any print or pattern reminiscent of a galaxy, generally consisting of blending, semiopaque patches of vibrant color on a dark background.