The Night-Sky in October

Abstract

SUMMER Time ends on October 2 at 2h U.T. The moon is full on October 9 at 9-6h (the Hunter's moon) and new on October 23 at 8-7h. Lunar conjunctions with the planets occur as follows: On October 5d llh with Jupiter ; October 9d 12h with Saturn ; October 21d 4h with Mars ; and on October 26d 0h with Venus. On October 12d at 9h, Mars is in conjunction with Neptune. The planet Jupiter is the dominating bright star of the evening skies; in mid-October it souths at about 20h. The various phenomena of the four inner satellites may be followed with the help of data given on pp. 618-619 of the Nautical Almanac for 1938 or in abbreviated form on p. 170 of Whitaker's Almanack. On October 16, Venus is at greatest brilliancy ; but the planet sets 43 minutes after the sun. Saturn is on the southern meridian at about 23-14;h in mid-October ; on October 8, it is in opposition, the distance from the earth being about 781-14; million miles. Mars is a morning star rising at 3¾h in the middle of the month. Two well-known variable stars are now well placed for observation during the late evenings.? Ceti, the variability of which was first recognized by Fabricius in 1596, is a long-period irregular variable. At maximum the star is usually of magnitude 3 or 4, but is occasionally of magnitude 2 ; at minimum it sinks to magnitude 9. The period is about 330 days. A maximum is expected near the beginning of October. The other variable, Algol (Persei), is an eclipsing binary the periodic variations in brightness of which Were discovered by Goodricke in 1782 as occurring at regular intervals of 2 days 20 hours 49 minutes. There are several meteor radiants listed for October ; the Orionids are seen at a maximum during October 18-20. On moonless nights, the great nebula in Andromeda, visible to the naked eye, may easily be located with the help of binoculars. The Pleiades are now well above the eastern horizon in the late evening.