GIANT STORMS IN THE SUN.

Oamaru Mail, Volume XXXVI, Issue 10060, 30 January 1909, Page 3 (Supplement)

GIANT STORMS IN THE SUN.

Important studies-of the sular cyclonic storms known to us ae> sun-spots are reported from the solar observatory oi the Carnegie Institution on Mount Wilson, near Pasadena, Cal.. -N'ew discoveries, made bv its director. Professor Lieorge L. Hale, with photographic aid, have thrown valuable light on the action taking place in a sun-spot, and;,have; proved oeyond doubt that sucli a spot acts like a powerful magnet.. .Says Professor fe. A. Mitchell, of Columbia University, who contributes an article oil the subject to lho Scientific American :, "By improved- methods of research, by careful diligence in closely observing the sun, aided by a little stroke of luck, photo-o-i-aphs have been taken which show a mass of cool hydrogen gas being tucked into the vortex of a sun-spot, the resuL of a terific solar cyclone. These photographs, we are told, which would be impossible if astronomers had the camera alone to rely upon, are made with the aid of the instrument called the spcctroheliograph, invented by Protessoi Hale himself. We read: . •'4.s the name signifies, the sun is photographed by means of its spectrum. A powerful grating or, prism-tram at the eye'end of the telescope spreads the suns light out into its spectrum. By allowing the light from one. line of the spectrum, as K or K.. to pass through, a secondary slit,'a photograpli of the sun and its surroundings cjin be taken m H or.lv lightalone. .... \Vitlj, the new spcctroheliograph if became ,possible to photograph not- only the prominences but, also the face of the sun, and if the secondary slit AVfive set. at the centre of the K lino at the violet- end of the spectrum, a plateof the sun was obtained in the light ot glowing calcium vapor. This photograph was decidedly different in appearance from that of a straight picture taken m the ordinary way ktil! later investigations led Professor .Hale to the conclusion' that it was now possible to take photographs representing the condition of the sun's atmosphere at- different elevations. When we think that- remaiivably little is known of our own atmosphere at a height of five miles above the earths surface, we get a slight idea of the power of the astronomer in photographing the sun ninety-three millions of miles awa), and gaining a knowledge of the condition of the sun's atmosphere at different levels 1 This work was of far-reaching importance, and it became more and more, necessary to photograph the sun daily. But at Yerkes and at all observatories in the eastern part of our country, daily work on the sun is often interrupted by _ clouds, and the advantage of a location in' California was recognised by the Carnegie Institution. Work there progressed along the same lines which had brought- so much success at-, the 'Yerkes Observatory: and Professor Hale planned to carry out researches on a grander scale than was possible even with the 40-inch telescope. In photographing the sun thus, by means of light from a single line in its spectrum, a picture is obtained of that part of the sun which is made up .of the substance giving off light of that particular color or wave-length. Hydrogen is responsible for several spectral lines, and ilie one generally used for visual observation is the C line, which is a deep red. Until recently no sensitive plates Responded to light- of this color, but latelv such have been prepared by Wallace, ot the Yerkes Observatory, and .jvere used by Professor Hale in his latest photographs. The taking of these is thus described bv Professor Mitchell: "On May 26, 1908, a spot reached the east limb of the sun at 8.16 a.m., and the looked-for opportunity was at hand, tin May 25. before the spot turned the edge o£ the sun. evidences of activity could be seen in the shape of prominences which w ; ere undoubtedly connected with the spot group. On May' 26, at 6.58. a.m., with the spot'very close" to the eastern limb, traces of a. cyclone could- bo seen near_ the spot, matter there being ill rapid whirling motion, and likewise was seen what- proved later to be of especial-interest —a flocculus of dark cool hydrogen. (The spot- remained on the face of the sun until Juno 8.) The splendid series of photographs taken show the cyclones continuing on a gigantic scale around the spot. The dark mass of hydrogen—the (locculi—showed changes hero and there, giving evidence of great agitation on the sun. Suddenly on June 3'"a, catastrophe happened; the cool hydrogen gas, which had been continuously in the same location since the spot came around the edge of the sun on May 26, was quickly set whirling and was rapidly sucked into the great maelstrom on the sun. Professor Hale was lucky enough to have this great solar cyclone—the first of its kind ever seen—recorded on a- series of nine photographs, all taken within ten minutes. \V*-e congratulate Professor Hale on his energy and his great fortune. The speed- at- which this cool hydrogen rushed into the centre of the spot was about sixty miles per second." Thus a mass of hydrogen gas has been traced before and after ,it has been drawn into tile solar furnace, and a new series of discoveries has been begun, which it- is hoped! will much increase our knowledge, of solar action. Further dispatches from Professor Hale indicate that he has discovered, in the light from a sun-spot, the peculiar distortion of spectral lines due to the influence of a, magnetic field, ,so that we now bave direct -evidence of the magnetic force observed is such as would we have long been 'Certain indirectly. The magnetic force observed in such as would be produced by .electrically charged particles whirled about in the gigantic vortex of the spot-, where they would act like a current in the spiral coils of an electromagnet.