Abstract
ON October 1 in the latitude of London, night (sunset to sunrise) lasts for 12·3 hours and on October 31 for 14·3 hours; civil twilight (the sun 6° below the horizon) shortens the night by more than one hour. The moon is new on October 12 at 20·5h. and full (the Hunter's Moon) on October 28 at 6·7h. U.T. There is an occultation of the third magnitude star, β Capricorni, on October 20, the disappearance as seen from Greenwich taking place at 17h. 52·0m. at position angle 42° and the reappearance at 19h. 4·7m. at position angle 282°. On October 28 there is a partial eclipse (magnitude 0·992) of the moon that is partly visible from London. The moon enters the earth's umbral shadow at 4h. 54m., reaches mid-eclipse at 6h. 36m. (13 minutes before moonset at London) and leaves the umbral shadow at 8h. 18m. This lunar eclipse is preceded by a total eclipse of the sun on October 12 visible in the Antarctic Ocean south of Australia, the limits of latitude for the central line of totality lying between 60° 0′ and 81° 28′ south. Lunar conjunctions with the planets occur as follows: on October 13 with Mercury; on October 21 with Mars; on October 25 with Jupiter and on October 27 with Saturn. Mars souths at about 19½h. in mid-October; Jupiter at 22½h., and Saturn at O½h. Saturn is in opposition to the sun on October 22 when the planet's distance from the earth is about 772 million miles. Close groupings of Jupiter's four inner satellites can be seen at 22½h. on October 24 and 25; in the 24-hour interval, satellites I, III and IV have swung from west to east of the planet. On October 19–20, Jupiter occults the ninth magnitude star B.D. -1°3. At Greenwich the immersion takes place at 22h. 3m. and the emersion at Oh. 6m. As the motion of Jupiter is retrograde at the time, the immersion takes place at the planet's west limb. The computed times are liable to an error of some minutes owing to the slow motion of the planet. From a radiant in Draco a meteor shower associated witli the comet Giacobini-Zinner (1900) may occur between October 8 and 10. The zodiacal light may be observed before dawn in the middle of the month. On moonless nights it is also worth looking for auroras, for the sun is still active and there is a pronounced seasonal peak in the frequency of magnetic storms in October, another peak occurring in March.
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The Night Sky in October. Nature 144, 591–592 (1939). https://doi.org/10.1038/144591e0
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DOI: https://doi.org/10.1038/144591e0