Sun Much Spotted

Manawatu Times, Volume 64, Issue 161, 11 July 1939, Page 7

Sun Much Spotted

WILL IT PRODUCE AURORA DISPLAY? The sun is at present very active, and is literally covered with spots. Observations made at the Carter Observatory yesterday show that they cover such a wide field as to make a nakedeye mark, only, of course, the sun must be looked at with the eye protected by smoked glass. A big group of spots came round on the sun’s visible surface at tho beginning of the month, and ever since tlien this group has been developing, now being a mass of spots of all shapes and sizes. To the north of this group is another group, which has developed from a few insignificant spots to a large group 86,000 miles long, and yet another group is developing to the south. The three groups arc apparently a zone of great activity. Speculation at once arises as to whether the sunspot activity will be accompanied by auroral displays. If there is an aurora it is usually when the sunspots have just crossed the sun’s meridian. The present spots have just crossed the central meridian, so if there was to be au aurora it would probably bo soon. In some astronomical circles it is believed that auroral displays sometimes follow active eruptions taking place in the spots themselves, not necessarily when the spots cross the sun’s central meridian.

Some of tho spots now on the sun arc in active eruption, so if this theory is correct, there is a chance of an auroral display at any time in the immediate future. It does not always follow, however, that because there are sunspots ♦.here must necessarily be an aurora. All that is known about the relation of the two phenomena is that aurorae, when they occur, are generally preceded by sunspots, but there are quite often sunspots without aurorae.