ROUGH ASTRONOMICAL NOTES.

Evening Star, Issue 8504, 1 May 1891, Page 4

ROUGH ASTRONOMICAL NOTES.

Mat, 1891. The Sun’s meridian altitude, and the New Zealand mean time of his meridian passage, rising and setting at Dunedin:— Day. Merid. Alt. OnMerid. Rises. Sets. hj. m. s. hj. m. hj. m. 3 28’ 37' 0 4 45 712 4 68 10 26° 39' 0 4 12 7 20 4 48 17 24° 55' 0 4 7 7 28 4 40 24 23° 28' 0 4 29 7 86 4 32 81 22° 17' 0 5 16 7 43 4 27 FBABXB OP IHB MOON. Last quarter—2d Ih 21m a.m. New moon—Bd 5h 46m p.m. First quarter—l6d 6h 84m a.m. Full moon—24d 6b 56m a.m. Last quarter—Sid 6h 25m a.m. Perigee— fid 9b p.m. Apogee—l7d 6h p.m. Perigee, June—ld 9b a.m. The Moon will be in conjunction with Jupiter on the 4th, with Venus on the 6tfa, with Mercury on the Bth, with Mara os the 10th, with Saturn on the 17th, and with Jupiter on the 31st. There will be a total eclipse of the Moon on the morning of the 24th. The times of the different phases are—First contact with shadow, 4h 11m ; beginning of total phase, 5h 20m ; middle of eclipse, 5h 59m ; end of total phase, 6h 39m, Moon seta 7h 36m. TRANSIT OF MERCURY. On Sunday, the 10th, there will be a transit of Mercury across the solar disc, which will be interesting to those possessing good telescopes should the sky be clear, as the planet takes nearly five hours to cross, The apparent diameter of Mercury at the time of transit is only 1-160 th that of the sun, so that it is doubtful if it could be seen without a telescope. The best way to observe is to project an image of the sun on a paper or cardboard disc, which can easily be done by lashing a slender rod to the eye end of the telescope, having a card tacked to its end. By this arrangement a group can view it without fatigue. The diameter of the sun’s image should be the same as the object glass, or a little greater, and a piece of cardboard, with a hole out in it to fit on in place of the cap, may be used as a shade. If the sun’s image is made Sin, the image of Mercury will be 1-320(1 of an inch. The first contact is 64deg east of the sun’s south point, or about 20deg above a horizontal line through the centre. At Ih 62m the planet is nearest the sun’s centre, 12.5 m, or l-9th of the sun’s diameter from the margin. The last contact is 12deg west of the south point. exact times of contact are as follow at Dunedin:— b. m. a First external contact .. 11 28 25 First Internal contact .. 11 28 19 Lub internal oontaot .. 4 17 11 Last external Sontaet .. 4 22 3