The most common and most likely answer to this crossword clue is the 6 letter word HYADES
I've seen this crossword clue in The Daily Telegraph
H
Y
A
D
E
S
More clues leading to the result HYADES
- The last place, perhaps, to introduce unknown stars
- Starry group appearing in Givenchy ad, essentially
- Group of stars with yen to hide in the underworld
- Appearing in biography, a desperate group of stars
- Greek god around young nymphs
- Those bringing rain in unknown quantity entering Hell
- Unknown in the Underworld, we’re always to be seen in the Bull
Buddy explains!
The straight part
We know that "Group of stars" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case group of stars = hyades.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.