THE PHOTOGRAPHIC STAR MAP.

Auckland Star, Volume XXXII, Issue 52, 2 March 1901, Page 2 (Supplement)

THE PHOTOGRAPHIC STAR MAP.

The new star map, or globe, which is being constructed under the auspices of the International Congress of Astronomers, is an amazing- work. Photographs are being taken of given sections of the sky from stations all over the world, these to be arranged into a complete map of the heavens. The patchwork of photographs .will cover an immense globe having a diameter of 24ft. During- the work 44,000 photographs will be taken, and a catalogue' of 2,500,000 stars will be made.' Altogether more than 30,000,----000 stars will be photographed. The lens of the camera is of more astronomical value than that of the finest telescope. More accuracy obtains in measuring a plate than was possible in visual measurement. One five hundred thousandth of an inch and less on a photographic plate furnishes data for accurate star measurement; where the telescope will show but 50,000,000 stars, the sensitised plate exhibits more than 160,000,000. Though light travels at the inconceivable velocity of 187,000 miles a second, yet light from stars in the range of the telescope takes 5760 years to reach the earth. We may see on the photographic plate pictures of stars, not as they are, but as they were perhaps half a million years ago.