The Night Sky in October

Abstract

THE moon is full on Oct. 5d. 8h. 32m. and new on Oct. 27d. 20h. 9m. There will be an occultation of the first magnitude star α Tauri on October 10, the disappearance as seen from Greenwich taking place at 3h. 16.lm. and the reappearance at 4h. 30.1m., the position angles being 290° and 252° respectively. Lunar conjunctions with the planets will be as follows: Mars on Oct. 5d. 23h., Mars 1° S.; Saturn on Oct. 9d. 4h., Saturn 2°N.; Jupiter on Oct. lid. 4h., Jupiter 5° N.; Venus on Oct. 23d. 17h., Venus 8° S. Mercury is an evening star until Oct. 26 and then becomes a morning star. Venus is an evening star and sets at 18h. 38m. at the beginning and at 18h. 19m. at the end of the month. Mars is a morning star until Oct. 10 when it is in opposition to the sun, and then it is an evening star. At the beginning and end of the month the planet souths at Oh. 41m. and 22h. 6m. respectively. Jupiter is a morning star and crosses the meridian at 4h. 44m. on Oct. 1 and at 2h. 44m. on Oct. 31. Saturn is a morning star, the meridian passages being at 3h. 8m. and 1h. 7.m at the beginning and end of the month respectively. The Orionid meteor shower will commence about Oct. 18 and will continue for a few nights; the radiant point is close to ν Orionis. Comet van Gent (1941d) will be visible with the aid of a small telescope during the month. It will be easily identified, a 3–inch refractor showing it quite distinctly, as its magnitude is about 8.5. The comet is moving northward in declination in the constellation Ursa Major, and on Oct. 19 will be close to ψ Ursaa Majoris. Its distances from the earth and sun in the middle of the month will be nearly the same—about 108 million miles. Although it is receding from the Sun it is still approaching the Earth, for which reason its magnitude will not vary very much during the month, that due to the increase in distance from the Sun being nearly balanced by the change due to the decrease in distance from the Earth. An ephemeris for every four nights is given for the comet. A short ephemeris was given in NATURE of Aug. 2, p. 139.