The word of the day is lodestar:
1. A star that shows the way; esp. the pole star.
2. fig. A ‘guiding star’; that on which one's attention or hopes are fixed.
"As a writer, Kael had such lodestars as Partisan Review, which she read avidly, and Dwight Macdonald, then its editor, with whom she tried to correspond. (In 1943, when she learned of his plans to launch Politics, she wrote to him, 'I am looking forward to a magazine which will stand for the principles and position you represented on Partisan Review.')"
- Nathan Heller, "What she said: the doings and undoings of Pauline Kael", 24 October 2011 The New Yorker