By: qed007

qed007 — Tue, 14 Jan 2020 17:35:51 +0000

Ok, I found an answer. Apparently Betelgeuse is only 4,5 times the size of the Sun in diameter. What many incorrectly refer to as the giant start that would extend to Jupiter’s orbit is actually a cloud of hot gas — a nebula — that has formed when Betelgeuse has spewed out its outer layers. What (almost) everyone seems to refer to as a ‘giant start’ is actually a cloud of hot gas, and the actual start is much, much smaller. Apparently the reference to an impressive size is so attractive that many are willing to overlook this small detail. To me, a star 4,5 times the Sun is still impressive, surrounded by a nebula or not.

By: qed007

qed007 — Tue, 14 Jan 2020 16:25:46 +0000

Dave, I have been wondering about one thing and could not find an answer in the web. Betelgeuse has 10-20 times the mass of the sun, yet its radius would reach Jupiter’s orbit. This means that Betelgeuse’s density — about 1.1 * 10exp(-8) that of the Sun. Yet it is apparently busy fusing lighter elements into heavier ones. How is this possible at such low density? Does it have a small dense core about 10 times that of the Sun and a cloud of hot gas surrounding it? If so, how does the cloud remain hot and not fall back into the core?

Comments on: Dimming of Betelgeuse – Supernova or not?

By: qed007

By: qed007