The most common and most likely answer to this crossword clue is the 12 letter word ASTROPHYSICS
I've seen this crossword clue in The Daily Telegraph
A
S
T
R
O
P
H
Y
S
I
C
S
More clues leading to the result ASTROPHYSICS
- Hit spy across bum for discipline
- Fool coming over almost ill after award for science
- Science prize thus bagged by idiot
- Working with stars, fool collects prize
- Dunce securing prize thus for branch of science
- Special prize so fitting in, for example, science
- Analysis of stars by psychiatrist so misguided it is deleted
- Like some editors' notes about prize for far-out subject?
Buddy explains!

The straight part
We know that "Working with stars" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case working with stars = astrophysics.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 ASTROPHYSICS mean?
ASTROPHYSICS noun- The branch of astronomy or physics that deals with the physical properties of celestial bodies and with the interaction between matter and radiation in celestial bodies and in the space between them.