CELEBRATED STAR

Taranaki Daily News, 3 January 1935, Page 6

CELEBRATED STAR

FAVOURABLE OBSERVATION. LOCATION OF “MIRA CETI.” “The present is a most favourable time to observe the celebrated variable star Mira Ceti, also known as Omicron Ceti,” writes Mr. G. V. Hudson, of Karori, to a Wellington paper. This, he says, may be done without the aid of a telescope. “Those not having access to a star map, or planisphere, may succeed in picking up Mira, now nearly of the second magnitude, by the following directions:—

“Facing due north at about 9.30 p.m. a group of stars will be seen roughly outlining the letter A, the well-known cluster of the Pleiades being to the left and the constellation of Orion -to the right “From the apex of the ‘A proceed slightly upward until facing the northwest, when a flat triangle of stars will be seen, its longest side almost parallel with, but some 45 degrees above, the north-western horizon. This triangle is formed by the stars Alpha, Gamma, and Delta Ceti. “If the longest side of the triangle be produced for an equal distance toward the south it will touch Mira Ceti now about as bright as Alpha Ceti. Mira’s present brilliancy will, however, only last for about a fortnight, when the star will de -rease for about three months until It becomes totally invisible to the naked eye. It will so remain for about five months, and then gradually recover its brilliancy -during the remaining three months of its period. “Its maximum brightness is not always the same, nor does it always increase or diminish by the same gradations, nor are the successive intervals of its maxima equal, but the mean period is about 330 days. “Mira Ceti was first observed to disappear by David Fabricius in the year 1555, but it was not until December, 1638, that Phocylides Holwarda discovered the true nature of its variations. During the period of its. invisibility to the naked eye, Mira sinks below the ninth magnitude. “While the variation of some variable stars of short period can be explained by a partial eclipse, due to the passage of a dark body between the star and the observer, no satisfactory explanation has yet been given to account for- variations similar to those exhibited by Mira Ceti.”