THE MILKY WAY IS RICH IN STARS WORTHY OF OBSERVATION

Wanganui Chronicle, 5 August 1947, Page 7

THE MILKY WAY IS RICH IN STARS WORTHY OF OBSERVATION

(By "SKY PILOT") In the northern sky at the present time, lying low down near the horizon, is a lamous cross sometimes considered more truly a cross than our Southern Cross. It is called the Northern Cross, or Cygnus. Five prominent stars in it trace out a distinct cross.

The star at the head of the cross is Arided (Alpha Cygni or Deneb). In tlie Southern Hemisphere it appears at the bottom. Actually, it is one of tile most remote of the bright stars, being probably over 1630 light years distant, and, since a light year equals 6 billion miles it is therefore 9780 billion miles away from the earth.

The nearest star visible to the naked eye is Alpha Centauri, the bottom pointer of the Southern Cross, which is 25 billion miles distant, or 4 1/3 light years away, so that Deneb is 377 times as distant. As it has a magnitude of 1.33 it is the nineteenth brightest star in the sky, and is believed to give out 10,000 times as much light as our Sun. Another very important point to remember about Lyra is that it is situated in the midst of a very bright portion of the Milky Way. The Milky Way has tremendous attractions in itself, and Is a grand field for study, ever capturing our admiration because of its sheer beauty. It challenges the mind because of its mysteries. For a constellation to appear in such environment is to add to its wealth and interest.

The Milky Way entering Cygnus, is interrupted by dark lanes. A great longitudinal rift which begins in the Northern Cross divides the Milky Way into two parallel branches almost as far as the Southern Cross, thus extending nearly a third of the way around the heavens. The western branch of this stream is the brighter one at first. Further south it fades in Ophiucus, but becomes conspicuous again in Scorpius. The eastern branch grows brighter as it continues southward and gathers into the great starclouds of Scutum and Sagittarius. Near the Southern Cross where the streams are united again, it is nearest the south celestial Pole. The dark portions are believed to be due to great masses of cosmic dust, which hides the stars behind it. If a cloud of such matter is near a bright star it is illuminated by the starlight and is faintly seen. The photographic plate exposed for about two hours reveals a wealth of star masses in and about the Northern Cross. When we look at Cygnus at night lying low on the northern horizon these facts will give us food for thought about this very rich region of the sky. It is an interesting fact that around the three crosses, the Northern, the Southern and the False, a wealth of starry material exists, and this, of course, is due to the fact that they all are immersed in the richness of the Milky Way. For this reason they are all objects of great profit for the observer. They fully require many hours of observation.