Question: I have a question about the ancient constellation Argo Navis. I am trying to determine from exactly how many stars it was comprised. I have seen one reference that lists an enormous number of stars. Another lists 26. Which is correct or isn’t there a definitive answer to this? – Darrell
Answer: First some history for the ancient constellation Argo Navis. According to Wikipedia, Argo Navis is the only one of the 48 constellations listed by the 2nd century astronomer Ptolemy that was not included in the 1930 International Astronomical Union’s formalisation of the constellation boundaries. Its enormous size in the southern sky made it unwieldy to use as a reference region for astronomical identification: were it still considered a single constellation, it would be the largest of all. In 1752, the French astronomer Nicolas Louis de Lacille subdivided it into Carina (the keel, or the hull, of the ship), Puppis (the poop deck, or stern), and Vela (the sails).
Now, as to the question of how many stars reside in this ancient constellation, there is at least one Wikipedia list which counts about 450 stars in Argo Navis. A somewhat more authoritative listing can be found in Allen’s “Star Names: Their Lore and Meaning”. Allen states that Carina contains 268 stars, Puppis contains 313 stars, and Vela contains 248 stars, for a total of 829 stars (all visible with the naked eye). I would trust the Allen reference.