World Without Stars make me think of Elliot S! Maggin's Superman 400? The latter is introduced by sf writer, Ray Bradbury, but that is not the connection.
In Maggin's story, Superman:
ages but does not die;
outlives everyone he knew and loved on Earth;
survives into a period of interplanetary, then interstellar, travel;
befriends and travels through space with the reformed Lex Luthor until Lex also dies;
eventually disappears from human ken;
becomes a legend, then a myth;
is commemorated at the Miracle Monday festival when each family sets an extra place at their table for Superman in case he returns -
- and one Miracle Monday meal is attended by Superman time traveling from the twentieth century.
Readers of World Without Stars will recognize some parallels. Hugh Valland:
outlives his fiancee, who dies on Earth;
lives for thousands of years;
travels through space and even between galaxies;
writes songs that are remembered;
will probably become a myth -
- and we do not know his ultimate fate.