Betelgeuse

The red giant star, Betelgeuse, is Alpha Orionis.

In Poul Anderson's Technic Civilization History, Betelgeuse has forty seven planets, six bearing life. The star's total radiation is great enough that its liquid water zone includes that many planetary orbits; however, not long enough for life, let alone intelligence, to develop. Because Betelgeuse is much more massive than Sol, it has spent only a short time on the main sequence and is dying.

Human explorers found an interplanetary civilization with vague traditions, although no extant records, of ancestors arriving from elsewhere and seeding lifeless planets:

engineered microorganisms can generate a breathable atmosphere in decades;
automated processes can produce soil;
plants and animals grown from cells can then be released.

Betelgeuseans:

have hereditary rulers called Sartazes;
now have the hyperdrive;
rule a few nearby stars;
will evacuate their system when necessary;
play potential enemies, like Terra and Merseia, off against each other;
are treated as a buffer state between imperia and barbarians;
have human citizens, some in key positions;
are short, stocky, bald and blue with large yellow eyes in round blunt faces;
trade with the human colonies, Altai and Unan Besar;
thus were, indirectly, the means by which Dominic Flandry ended Merseian subversion on the former and a dictatorship on the latter.