GLORY OF THE STARS

New Zealand Herald, Volume LXXV, Issue 23104, 1 August 1938, Page 8

GLORY OF THE STARS

heavens in august RECENT AURORAL DISPLAY APPEARANCE IN DOMINION __ • | BY CJBUX JLTTSTBALIS s Although auroral displays have been of frequent occurrence in New Zealand in the past year or two, with a few really splendid displays visible all over the Dominion, it is probable that not many persons in the northern portion of this island have witnessed a great auroral display. following description of the aurora which occurred on Easter Saturday, April 18, written by Mr. M. Geddes, as it was seen in will be of interest. The aurora began with a great ,burst of activity as twilight faded, writes Mr. Geddes in Southern Stars, filling the south-western and south-eastern sky with masses of broad crimson rays, while a high arc spanned the southern sky. Rapidly the rays to east and west broadened until they merged into intensely bright crimson patches. Meanwhile, above the arc, bundles of rays shot up, green at the base and merging into pink above as they passed out of the dark into the sunlit atmosphere.'

Bright, Green Band Develops So far there had been nothing unusual about the display, but at 7.12 p.m. a bright green bancl developed and spread from east to west through the zenith. No sooner had-this formed than it began to move laterally and with considerable speed bodily across the sky toward the north. In less than a minute it was low down on the northern horizon, where it glowed steadily for a few minutes and then faded out. The rays surmounting the arc had now assumed a complex drapery formation in constant change. In the east the moon rose in the midst of a blood red haze, while the whole sky, even on the northern horizon, was suffused with a dull red light. As the rays approached and crossed the zenith they converged and met at a point near the magnetic zenith to form a corona—a - pink crown of light with rays converging to it from all directions. Second Phase of Activity The second phase of activity, commencing at 10.18 p.m., was very nearly as bright as the first and very simi-. lar—a huge drapery formation, rays crossing the zenith, and a laterallymoving green band. The isecond maximum occurred about 1.0.45 p.m. Gradually the ray activity declined and goon only a bright arc extended across the sky. This brightened slowly, until, at 1.46 a.m. the third . maximum period began. The arc began to flame. This was at first barely discernible, being just a faint series of flickers at intervals of some seconds, but soon it was flaming brilliantly. The normal aurora flames in the form of a succession of waves of light rolling* up from the horizon across the main forms, but in this case it was vastly different. About once a ~ second the whole arc shot bodily upward some ten degrees, fadpd out there and re-appeared at the samp instant in its original position. In no sense did it move up and down. It was just as though a series of arcs wenforming one after the other, each jerking upward and disappearing to give place to the next. At intervals a fen rays participated in the display.

Feature of Auiorae This maximum was probably reached at 2.15 a.m., when a slow decline set in. In ail! aurorae so far recorded in; New Zealand —in contrast to the Norwegian experience— the development of the flaming type has invariably marked the death of the display and the Easter aurora was no exception, Mr. Geddes concludes. The activity declined gradually and steadily until at 4 a.m. the aurora was barely visible. Clouds prevented the tracing of its history beyond this stage. The main region of the auroral display oscillated between Stewart Island ana the Snares. During the maximum period, however, some of the auroral forms actually were situated over New Zealand. Phenomena for August. The Sun will be ,in the constellation Cancer until August 10, when it will pass into Leo. Its noon altitude at Auckland will increase during the month from lio degrees to 44 degrees. The Moon will be in conjunction with the various naked-eye planets as follows: —Jupiter, 12th, 6.30 TWP-; Saturn, 16th, 4.30 p.m.; Vfcnus,H29th, 10.30 a.m. . ~ The planet Mercury is at present well placed in the evening sky, being visible a little below the brilliant enus, also an evening star at. present. By the end of the month, however, Mercury will be in conjunction with the Sun ana invisible to us. "Venus will be only nail a degree from the star Spica on August 31 Jupiter is now splendidly situated for observation, being in opposition on the 21sst, when it will be above the horizon all night. It lies near t border between the constellations Oapricornus and Aquarius. _ Saturn rises later in the evening, being m the constellation Pisces. Its unique ring system is beginning to open out /gam l-™ I remaining naked-eye planet. Mar , I too closio to the Sun to be obsened.