GLORY OF THE STARS

New Zealand Herald, Volume LXXV, Issue 23026, 2 May 1938, Page 6

GLORY OF THE STARS

HEAVENS IN MAY remarkable discovery HUGE INVISIBLE BODY BY CRUX AUSTBALI9 Astronomical discoveries often have a chastening effect on the human mind, revealing how really insignificant we Lilliputians are in the Universe. Within the past twenty years the dimensions of several stellar giants have been measured, with astonishing results. Antares, for example, the bright red star in the constellation of Scorpio, is 400.000,000 miles in diameter. Betelgeuse, a red star in Orion, has a diameter of 273,000,000 miles. So tremendous are these stars, in comparison with others which had been termed "giant stars" that Antares geuse were called "super-giants. Now, however, it appears that these super-giants are but dwarfs in comparison with Epsilon Aurigae, whose diameter has recently been determined by Dr. Otto Struve, director of Yerkea Observatory in the United States. New Category of Stars Now known as the largest star in the universe, Epsilon Aurigae- has long provided an interesting problem for astronomers. Only of moderate brightness, it has been observed that every 27 vears the light of the star was reduced bv about one-half, and it was believed that the diminution wa 3 caused by an unknown dark body revolving about the luminous star and periodically cutting off some of its light us seen from the Earth. This super-giant of space belongs to the recently - discovered category of stars known as the infra-red, or black, stars. Because they radiate only the invisible infra-red rays they had Until recentlv escaped detection, and they still remain invisible even in the most powerful telescopes. The existence of the new star has been arrived at purely by inference, but the inferential discovery of stars has occurred at least twice before in astronomical history and we can have confidence that in this case also the assumption is sound. r v Enormous Dimensions

In attempting to combine photometric and spectrometry data Dr. Struve was led to the belief that only a star of enormous dimension#* "C&uld account for the paradoxical phenomena recorded. The diameter of the ghost star must be 3000 times that of th 9 Sun. or 2.600.000,000-miles, far exceeding the dimensions of any star previously known. Such dimensions are incomprehensible without some terrestrial analogy. It is a matter of common knowledge that a New Zealander listening to a broadcast from Europe hears the speaker's words before they are audible to the people at the back of the large hall in which the speech is actually delivered because the radio waves travel so much faster than sound waves. On the immense companion of Epsilon Aurigae, however, the orator's audience would have heard the speech apd have returned to their homes to sleep, and the pages of the morning newspapers containing the words would be running off the presses before the Antipodean listener could hear the message actually spoken more than six hours before. Phenomena for May The Sun at present is in the constellation Aries, from which it will pass into Taurus on May 14. Its noon altitude at Auckland will decline during the month from 38 degrees to 31 degrees. During its circuit of the zodiac the Moon will be in conjunction with tha various naked-eye planets as follows; Venus, 2nd, 6.30 a.ra.; Mars, 2nd, 12.30 p.m.; Jupiter, 23rd, 4,30 a.m.; Saturn, 26th. 1.30 p.m.; Mercury, 28th, 10.30 a.m.; Mars. 31st, 5.30 a.m. Two eclipses will occur during May. The first, a total eclipse of the Moonj will be visible in New Zealand on the night of May 14. Umbra! eclipse will begin at 6.27 p.m. and will end at 10.1 p.m. Mid-eclipse will be at 8.13 p.m.; the total phase extending from 7.48 to 8.39 p.m. The second eclipse,, a total solar one, will be visible only in the Atlantic Ocean, partial stages "being visible at sunrise and sunset from the coasts of South America and South Africa. The planet Mercury will attain its greatest elongation in the morning sky on May 19. Venus, which has been visible as an evening star for the past month, is attaining a more prominent position and waxing in brightness. It will be in close conjunction with* Mars at mid-dav on May 8. Mars itself is drawing closer to the Sun, and is far too remote to excite telescopic interest. Jupiter, shining brilliantly in Capricornus, is visible during the last half of the night, while Saturn is closer to the Sun in the morning sky.