ASTRONOMICAL NOTES FOR JANUARY.

New Zealand Herald, Volume XL, Issue 12457, 30 December 1903, Page 1 (Supplement)

ASTRONOMICAL NOTES FOR JANUARY.

[BY J. STUART, BRITISH ASTRONOMICAL ASSOCIATION.]

The new year begins with Mercury visible in the western sky over the sunset, as the planet will be some 19 degrees from the sun's plao© on the Ist, and sets that day at twenty-six minutes to nine p.m., while tor about the first ten days of the month ho will be visible as an evening star. On the 6th, between nine and ten p.m., he Will cross the equator from south to north, and on the Bth, between two and three p.m., reaches his first stationary point in the third degree of the sign Aquarius, and begins to move retrograde, or backwards, among the stars. At noon on the 11th he will be m his perihelion, or nearest point to the sun, and thereafter becomes lost in the sunrajs; as he reaches his inferior conjunction or position exactly between the earth and sun, on the 17th near midnight. Shortly afterwards he will be in conjunction with the moon, and on the 21st, at seven p.m., will reach his greatest northerly distance from the ecliptic. Chi the 29th, near eight a.m., he reaches his second station, ceases to retrograde, and becomes once more direct, having gone backwards no less than seventeen degrees ol longitude. After the 17th he will be a morninsr star, but need not be looked for earlier than the last week of the month. Leaving Capricorn on the Ist, he makes a short excursion into Aquarius up to its third degree, and by the 31st lias gone back so that he will then be found in the eighteenth degree of Capricorn. . , . . Venus is still the most prominent object in the morning sky, as she rises on the Ist at five minutes past two a.m., and on the 15th at only one minute later. Un the Aid she reaches her greatest heliocentric latitude ' north, and on the 14 th will be seen somewhat to the'east and south of the moon, the conjunction occurring about seven a.m., or in daylight. She only comes neai to one fixed star of any magnitude (third), which takes place on the 6th, while she is below our horizon; but on the morning ol the 7th she will be about half a. degree to the east and a degree and a-half to the north of the star, which is known as Beta! Scorpio, situated in the second degree of Sagittarius. On the 29t'n she will rise nearly in conjunction with Herschell, that planet being' then a degree and three-quarters to the south and half a degree to the east of Venus; so that anyone who wishes to find the planet svith a telescope will be able to do so. Observers who wish to be able to say they have seen the otherwise invisible planets discovered since 1780, should not miss suoh opportunities as this; since it is then always easy to identify the objects. Venus will move during January from the twenty-sixth degree of Scorpio to the second degree of Capricorn, with latitude varying from the third to the second degree north. Mars will be found all the month between the sixteenth degree of Aquarius and the tenth degree of Pisces, with about a degree of north latitude, and he sets on the Ist at twenty-nine minutes past nine p.m., and on the 15th at five minutes past nine p.m. On the 10th, at nine p.m., he will be in conjunction with the star Delta Capricorni (in the tail of the goat), and a degree and ahalf to the north of it. This star is situated in the twenty-third degree of Capricorn, and is of the -third magnitude. Speaking of such observations, the old astronomer, Thomai Street, who wrote in the days of Charles the Second, tells us that "Anno 1461, Deoembci 25. sh. 30m., reduced unto London, by the observation of Regiomontanus, Mars seemed conjunct in the same longitude with the following brighter star in the tail of Capricorn. Street also says:—"l6ss, October, the 18th day, 9h., I observed Mars with a perspective in or near the same longitude, with the first of the two bright stars in the tail of Capricorn, but in lesse south latitude, about 6m." Such quaint records serve to show in what estimation these observations were held in former days. On the 21st Mars will be seen some three degrees to the south and a little to the west -of the crescent moon; rather a pretty sight if the sky should be clear for it. _ . Jupiter still remains the most prominent object in- the western evening sky, setting on the Ist at four minutes to eleven, arid or the 15th at eight minutes past ten p.m. ll< will' during the month move from the 18tl: to the 24th degree of the sign Pisces, in the second degree of south latitude. He is at present in a somewhat barren part of the sky, and therefore does not approach any stars 'worth noting. On the 22nd, at halfpast - nine p.m., he will be slightly to the east of the moon, with about a degree and a-half towards the south of her centre, and the moon will then be nearing her first quarter. Saturn is now falling behind Mars in the evening sky after their conjunction on December 21, and sets on the Ist at four minutes past nine, and on the 15th at fourteen minutes past eight p.m. He will be found between the eighth and- twelfth degrees of Aquarius, with less than a degree of south latitude. On the 19th, about nine a.m., he is in conjunction with the moon, and on the evening of that day will be seen some six degrees to the west and four or five to the south of her centre. He does not approach any fixed stars worth noting this month, and is daily becoming less conspicuous as he approaches his conjunction with the sun. Herschell rises on the Ist at eleven minutes to four a.m., and on the 15tli at two minutes to three, so that he is now in the eastern morning sky, and between the 27th and 29th degrees of the sign Sagittarius, not near to any special stars. Only telescopists will be likely to see him. Neptune is on the meridian on the Ist at twenty minutes to twelve p.m., and on the 15th at seventeen minutes to eleven. An opportunity of identifying him will be afforded to those having good telescopes, by his conjunction with the third magnitude star, Mu Geminorum, near midnight on the 17th, when the planet will be found only about the semi-diameter of the moon to the south of the star, and both will pass the meridian at thirty-five minutes past ten p.m. Neptune is retrograding in the fourth and third degrees of the sign Cancer at present. The moon will be full at seventeen minutes past five on the 3rd, in the twelfth degree of Capricorn, and in her last quarter on the 10th at twenty minutes to nine a.m. She will reach her conjunction with the sun on the 18th, at seventeen minutes past three a.m., in Capricorn, 26 degrees, a"nd in her first quarter on the 26th at eleven minutes past eight a.m. Her greatest declination north of the ecliptic occurs near midnight on the 2nd, and near noon on the 30th, at which times she will be in declination 13 degrees 26 minutes, and 18 degrees 20 minutes respectively; while her similar excursion to the south will reach their maximum near midnight on the 15th, amounting to 18 degrees 24 minutes. On the Bth, thirty-nine minutes after midnight, she crosses from north to south of the equator, or in longitude one degree 26 minutes of the sign Aries, and on the 23rd, at twelve minutes past one p.m., she passes from south to north latitude, in Libra 0 degrees 43 minutes. She is At her least distance from the earth on the 4th at midnight, being then in the first degree of Leo; and will be at her greatest distance on the 20th at half-past ten a.m., in the twenty-fourth degree of Aquarius. Whoever will take the trouble to note the position of these points from month to month will find that while on the whole they progress among the stars, yet it will be found that their movement is exceedingly irregular a fact first noted by the Arabic astronomer, Arzachel (who observed in Spain), in t the year 1080, but it was definitely discovered by the celebrated Jeremiah Horrocks, about the year 1640. The sun enters the sign Aquarius at twentyfive minutes past- ten p.m. on the 21st, and passes through his perigee, or nearest pointto the earth, at half-past three on the 3rd. -the days are now gradually shortening, as may be seen from the time of the sun's rising and setting, which are on the Ist at 4h 44m. a.m. and 7h. 22m. p.m., and on the 15th at sh. om. arid 7h. 26m. The day is therefore of 14h. 33m. on the Ist, and 14h. 26m. on the 15th, counting from the time when the sun's upper limb begins to appear m the horizon and disappear beneath it. Ihe prevalent winds have still been northerly during December, but with more breaks than in preceding months. The rainfall during the 29 days from December 1 to Decembei 29 inclusive has beer 3.19 inches, the number of days on which rain fel 1 w Auckland being 13; while the barometer's pressure has ranged from 29.4b inches on December 16 to 30.07 inches on December 22. The temperature has varied from 56 degree: Fahrenheit on December 13 to 7/ degrees on the 26th and 28th. The maximum range of temperature on a given clay (December 26) was 57 degrees to 77 degrees. For the same interval last year the rainfall was 2.44 inches • the barometric range from 29.73 inches to 30.29 inches, and the number of days on which rain fell was 15. The temperature ranged from 50 degrees to 75 degrees, and the neatest range (December 10) was from 50 5 degrees to 70.5 degrees. We may expect very high tides on the 3rd, and high tides on the 18th; while they.will be low on the 9th and oh the 26th.