SOLAR ACTIVITY

Dominion, Volume 12, Issue 143, 12 March 1919, Page 6

SOLAR ACTIVITY

Mr G. V. Hudson, of Hillview, Karon, writes'.-"Considerable solar activity pre-' vails at the present time. lh? great eunspot group reported in the middle of February has returned somewhat diminished in size, and is now .considerably past the centre of the disc. Two other important groups have also appeared, and' have not yet reached the central meridian, one being near the eastern limb, of the sun. These three groups very clearly mark the southern sunspot zone. The position of tho ' northern. sunspot zone is indicated by another group, which is entering the disc at a different point on the eastern limb. All these groups may be observed with advantage, during tho next four or five days, with the aid of a email telescope, the evo being protected with smoked, or dark-coloured glass. They will bo seen to advance on the disc each day, as they are- carried across by the rotation of the sun on its axis. When any special group is disappearing on tho western limb, its return may be looked for'on the (astern Imil) about thirteen days later. Some groups may be thus identified during several solar rotations."