ASTRONOMICAL NOTES FOR MARCH.

New Zealand Herald, Volume XLIX, Issue 14927, 27 February 1912, Page 4

ASTRONOMICAL NOTES FOR MARCH.

BT S. STUART. BRITISH ASTBOXOMICAL ASSOCIATION. Althocgh this is (ho time of the. year when it might be expected that the skies would be in the moat favourable state for observers, yet they have not proved to bo so, as most evenings the sky has been hazy, if not overcast, and thus no satisfactory work could be done except at opportune moments. Wo shall this month have Mercury to iho eastward of the sun ; and although up to •'* middle the little planet sets no later ♦ Wan on. 48m. yet his distance to the eastward of our luminary increases until by the 28th between one and two p.m., ho will have reached his present maximum elongation, which is nearly the least it ever has; being only 18deg. 51m. or a little less than a degree greater than its smallest value. Mercury leaves his I superior conjunction with the sun on the third between one and two a.m. ; and by the 15th between seven and eight I p.m. he has passed his ascendI ing node or crossed the ecliptic I from south to north. He will pass through his perihelion, or least distance from the sun in space, on the 20th at ICh. 30m. a.m., and in the afternoon of tho same day will pats about a degree to the north of the moon's apparent centre, whereby ho will be found to tho west of her a short distance just before setting, if daylight permits of his being seen. Reaching his greatest heliocentric latitude north of the ecliptic on the 30th between five and six p.m., he this month pursues his course i from the ninth degree- of Pisces to tho ! 29tb of Aries ; in latitude from the second i degree south to the third north. ! Venus is still the prominent morning star. as she rises 'on tho 15th at 42m. after three a.m., and is now moving between the eighth degree of Aquarius and the 15th of Pisces; whence it appears she is to be found among the stars of tho constellation* Capricorn I and Aquarius. Her distance to the south j of the ecliptic, or latitude, is from one to I two degrees. Tho nearest approach which j the moon will make to Venus this month will be some three degrees to the south of her; which occurs in the evening of the 16th, so that the planet will rise before our satellite on the 17th. It will still bo some time before wo see Venus again as the evening star, as her distance to the west of the sun only decreases five degrees during March, leaving her 25 degrees to the west. Jupiter can now be seen in the late evenings, as on the 15th he rises at lOh. 16m. p.m. He passes his occidental quadrature, or 90 degrees to the west of the sun, on the fifth between three and four J p.m., and on the 10th will rise just to the I west of the moon in longitude, and somewhat more than five degrees due north of her centre. His present course is in the first degree of north latitude, and from the 14th to the 16th degree of Sagittarius, among th« stars of the constellation Scorpio. In about two months'" time he will be in the best position for observers. Mars sets nearly as Jupiter rises, or on the 15th at 10h. 22m. p.m. This is because the two planets ire nearly in opposition to each other, Jupiter in Sagi*. tarius, and Mars moving between the 13tfc and 28th degrees of Gemini, where he is coming southward from the third to the second degree of north latitude. His) quadrature to the sun towards the east or oriental, takes place on the fifth between four and five a,m. Mars will be situated about three degrees due south of the moon on the 25th near eight p.m. Ho is now receding from the earth, or rather we are becoming more distant from him; as tho sun gradually approaches the ruddy planet, which is most distant from us when our luminary overtakes him. Saturn is now becoming more and more inconspicuous every day, as he is getting far over towards the west during our evenings, setting on the 15th at Bh. 46m. p.m. He is moving 16th and l 19th degrees of the sign Taurus, and there- ! fore near the triangle in the constellation i Aries, and in the third degree of south i latitude. Telescopists who $ desire to see ! him can still do so, but not to the same advantage as a couple of months ago, as the planet is getting too far awav from us. Herschell still remains in a situation which is not good for observers, as he rises on the 15th at lh. 45m. a.m. He will be situated some four degrees duo north of the moon on the 14th near seven p.m., and is moving between the second and third degrees of the sign Aquarius, or in the head of the constellation Capricorn, with half a- degree of south latitude. Neptune is in a much better position for observing, as ho will set on the 15th verylate, passing our meridian at Bh. 3m. p.m. He may be identified by telescopists on the 27th in this position, when the moon will be to the north-east of the planet about seven degrees; but her glare will be a disadvantage. However, after the planet has once been picked up, it is easy to mark his position by neighbouring stars; and he can then be better examined when the moon is not near. One hour before noon on the 21st tho snn will enter the sign Aries, which is the vernal equinox of the northern hemisphere, but the beginning of autumn with us. It was. because of the gradual drifting away of the equinox from the 2lst of March until it had got back to the 10th, that the reform of the calendar took nlace in tho 16th century ; as it was thus seen that the year had been estimated too long in the time of Julius Ceasar and onward, and that it was necessary,to intercalate a, day each three or four centuries to make up the difference. The length of our Auckland day on the first will be 12h. 52m., on the 1511) it will be 12h. 18m.. and on the 30th lib. 45m., as the time the sun is above the horizon is now decreasing most rapidly. Our clocks on the first when the sun is on the meridian, will indicate I2h 3m. 295., which on the 15th will be 12h Om. 55., and on the 30th llh. 55m. 355. The moon will pass her opposition to the sun on the third at lOli. 12m. p.m., in the 12th degree of the idgn Virgo, and the last quarter will take place on the 11th at 7h. 26m. p.m. She becomes new oh the 19th in the 28th degree of Pisces at 9h. 39m. a.m.. and will reach her first quarter on the 26th at llh. 32m. p.m. She passes her apogee on the 13th at 4h. 12m. pm and her perigee on the 29th at Bh. 30m' |

About three-quarters of an hour to the west of the meridian, and at an angle of 68 degrees above the horizon on the° 15th at nine p.m., will be found the constellation Argo Navis, which is one of great antiquity. Its principal star, Canopus, is an easy object to us, but is not visible in England. And just upon the meridian, at an altitude of 60 degrees, will be found the constellation Hydra, of which Eta hydra? is double, consisting of two stars respectively of the fourth and eighth magnitudes at a distance of three seconds from each other. 108 P. 8 Hydra is also a double, separated ten second's, of magnitudes six and seven respectively. ' On the 15th at nine p.m.. the bright star Spica Virginis, celebrated in history and mythology, will be seen right above the eastern horizon, with Aldebaran nearly in a similar position in the west. Above Aldebaran will be seen the striking constellation Orion, with its conspicuous stars Eiegel and Betelceu.se. Above them near the meridian, will be found Sirius •' and below .this, low down. Castor and Pollux nearly due north. One third of the way tip to the meridian, and about the same distance to the east of it, will bo found Regidus, or the Heart of the Lion The stars of the Southern Cross are now to the east of the south pole, and about the same distance to the west of it will be seen the bright star Achernar, the nolo lying nearly in a right line midway between them. Above Castor and Pollux -i third of the way up to the zenith, is Procyan, Cams Minor, or the Little Doe All these stars are more or less celebrated in history and in astronomy, and the student may profitably look up the mytho logical stories connected with them. * Mr. N. Lockyer has written a very interesting book on tins subject, with abundant proofs of the truth of his observations, and clearing up many things which have .formerly been a mystery to astronomers,