A new star beginning to look like stars generally (6)
I believe the answer is:
Here is my best explanation:
'like stars generally' is the definition.
'a new star beginning to look' is the subsidiary indication.
'new' is an anagram indicator.
'beginning to' says to take the initial letters.
The initial letter of 'look' is 'l'.
'star' is an anagram of 'stra'.
(Other definitions for astral that I've seen before include "Relating to stars", "Pertaining to the stars", "Altars (anag)", "Universal", "Characteristic of stars", "starry", "Stellar", "Related to the stars", "19 [STELLAR]" and "Like the stars".)