KEEPING AN EYE ON THE SUN.

Hokitika Guardian, 18 August 1923, Page 4

KEEPING AN EYE ON THE SUN.

(Hy Dr 'William •). S. kockyer, of the Norman ljoekyer Observatory).

A recent annoum oment t hat t lie Australian Government has deckled to establish a solar observatory in that country may not seem very thrilling to the ordinary individual, but it is of outstanding interest to astronomical

[everyone knows that it i- duo to the dominating heat and light ol the sun that life on this earth is possible, and many of us arc also acquainted with the facts that the weather anti also the number of magnetic storms, aurorae, and earthquakes vary from one year to another.

The past study of the sun Tins shown us that he is in a continual state of turmoil. (Jn his surface spots and other markings are seen to wax and wane, being more numerous in some years than in others. On his *‘iimh,” or edge, storms or prominences,violent outbursts of uprushing gases, behave very similarly. Observations during total eclipses have demonstrated that the upper reaches of the solar atmosphere, as exhibited by the •corona,” undergo great variations in shape and extent.

Th ese and other facts show that the sun undergoes changes in , light and heat irom one year to another, and it ha- been ascertained that all these phenomena complete their cycles in about eleven years. There are indications of shorter and longer cycles of disturbances, but these up to the present are not so well determined. The continuous and detailed study ol solar changes is therefore of supreme importani c if we are to—and we must —increase ottr know lege about the sun. If the study of file suit was limited to the work of one observatory the records would be very sparse, because no observations ran be made at night time or on cloudy days.

An t [fort was therefore made to plat

,i,lnr observatories, first in localities where the raw material, sunshine, was profuse, such as India, and, secondly, to distribute the observatories in longitude—i.e.. oa-t and west—so that

w!mu one ob-crviitorv is experiencing ui .lit the other is in daylight.

Tims ii wits desired to institute a chain of stations round the world so that at cverv moment of time the sun coni.i he under observation. At pn sent observatories for making this study are located in Central Kurope, Kngland, America, and India, taking the countries in order from cast to west. 11 will be seen, therefore, that there is a great gap in longitude between America and India, and d is tliii- gap which, for a long time, It has been wanted to fill. Sonic years before the war efforts were made t" promote tin observatory in Au-lralia. and while the site for the capital city of Australia Canberra/ was in proee-s of survey it was suggested that the ob-enntoiy should lie placed somewhere near this position. Already a .small telescope had been creeled on the proposed position and observations were in progress to test the at mosphciTc condition-. The meteorological conditions were till in favour of a good observing station. When ! was passing through Australia in II II I atts asked hy M,r King O'.Mailey, one of the Federal .Ministers, to inspect the site. It was situated a few miles from the capital litv oil a hill called Stromlow, being -,GoOft above sen level and (iOOft above the neighbouring plain. At that time the region was of rather a melancholy nature, being strewn with ring-barked gum trees and dead rabbits, the latter having been systematically poisoned. The site, however, seemed admirable from n solar observatory point of view, and Ibis w:i - expressed in a report that was subsequently communicated.

It i- now good news to hear that this gap in the chain has been filled in ami iiiai Australia will soon bn taking part m tlie international scheme lot solar research;