BETELGEUSE

Hokitika Guardian, 27 March 1923, Page 1

BETELGEUSE

DDFISTS AS TO ITS SOLIDITY. The bigness of lieUdgeme th o- not lie in its lruiy, but in the immense extent of the luminous atmosphere which surrounds it. according to the llieorv recently advanced Ly Yl. Veviiuiet, the a irtmomer of the Strasbourg Observatory, ni the Congress for the Adi aiiccmeut of Science, held in France. M. Yerrouet frankly stated iiis belief that no star as toga- Uetelgcu.-e could exist- in a solid mass. According to the measurements of Professor Michclson at Alt. Wilson Observatory, it is .300 times greater in diameter than the sun, with a circumference greater than the whole orbit of the earth, "he-oas Sirius, the most bidliauL normal M.lithe sun. M. Yci rolled cited ineasur'emellts ol other giant stars, such as Ai.taros, which has fortv limes the diameter of

the sun, in snppoit of his theory. The i sta Idi-lied Lias, he said did not admit an explanation ot the physical equilibrium of tlie-e gi.dut stars, and lie quoted determined laws ol corrclat 'on. ma-s and temperature to show that in no ease could one id these giant stars exceed in actual mass two or three times the size of the sun. Wlir.t gave them their gigantic appearance. he said, "as that their ma-s was surrounded by an immeti-e luminous envelope forming a photosphere. Something analogous to this envelope, but much les- brilliant, "’as to Pe found in the sun's corona. If an effulgent photosphere stretched beyond the sun's atmosphere at the level cl the corona, something like a giant star o. the Be tel go use kind would he produced. But to produce this effect the sun's superficial heat would have to he raised to 300,000 degrees. An outside stable envelope with diameter equal to 310 times that of the sun would then be formed.

Ultimately, says YL Yerrouet. these giant stars become normal as their en-

velopes contract with too decline cf heat, turning successively yell ov and blue.