ASTRONOMICAL NOTES FOR JUNE

Otago Witness, Issue 2934, 8 June 1910, Page 41

ASTRONOMICAL NOTES FOR JUNE

By John Grace, F.R.A.S. THE SUN. The path of the Sun during this month will be from R.A. 4 51 47, north declination 21 5 A in Taurus, to 6 56 N. 25 11 in Gemini; in longitude 69 57 to 98 16, passing the northern solstitial point on the 22nd at 7hr 19min.

THE PLANETS. Mercury will be a morning star all the month, passing the Moon about 4-deg to the south, on the 6th. On the 20th it will reach its greatest elongation, 22.48 west. Venus will also be a morning star, being two hours and three-quarters in advance of the Sun all the month. It- will be in conjunction with the Moon before its rising- on the morning of the sth, and also with Saturn on the following morning. Mars will be visible during the evening hours, setting between two and three hours after the Sun. It is still far north, its declination at the beginning of the month being N. 23.24, which will be gradually reduced to 19.42 at the end. Its distance from us is still increasing. The Moon will be near it on the 10th. Jupiter whose declination is now less than one degree south, rises in the afternoon, and, at the beginning of the month passes the meridian at 7.40, so that it is well-placed for evening observation. The Moon passe® it on the 15th. Saturn must be looked for before sunrise, being 2hr 30min in advance of the Sun at the beginning of the month and 4hr at the end. Its declination is N. 10. The Moo ll will pass it at 2 a.m. on the sth. Uranus, nearly 22 south, will be on, or near, the meridian at 1.30 a.m. Neptune, R. A. 7.16 to 7.20, declination N. 21.39 to 21.30, setting soon after the Sun, is not conveniently placed for southern observers. CULMINATIONS. The following bright stars, as seen from Dunedin, will culminate at the hours named on the Ist of the month, and 3min 56see earlier daily afterwards; —

dian of Port Chalmers, and reduced to New Zealand standard time—llhr 30min fast of Greenwich. 7 For inland places on or about the same latitude one minute should be added for every 12 miles westward. If a compass is' used for finding the meridian, allowance must be made for its variation, which is given as 16.48 east of true north. COMETS. The return of .Halley's Comet to our neighbourhood has led to many inquiries as to the nature of comets generally, and to the probability or otherwise of their injuring our planet or its inhabitants. Concerning these matters some most extravagant ideas and theories have been propounded, partly through ignorance, but more frequently through mischievous imagination, which latter, in many cases, is given expression to as if it were known fact. It may have been noted 'that the majority of those who had studied the subject evinced .no fear either of the comet or of its tail. In answering inquiries, we" are not able to state positively what a comet or its tail oonsLts of, but its path in the heavens indicates that it is subject to the laws of gravitation, being attracted t>y the planets, yet producing no visible effect on them. W-e therefore adjudge it to be a material body having very little density. But if it i 6 attracted by the Sun, and planets, may it_ not come into collision with them? This seems a feasible question, and the only answer we can give is that we have no-evidence of 6uch an event haying taken place, and until we have it is only fair to assume that the solar system possesses inherently the elements of stability, and that even if, as some think, a toll of oometic matter ; s exacted at every approach to the ruling centre, we note that the comet goes on its way again as if nothing had happened. This is clear in the case of those which move in elliptic orbits, but there is a much larger number whose orbits cannot be differentiated from parabolas or hyperbolas. What becomes of them? We see them approach and then depart from our Sun, apparenly never to return. If our diagnosis of their orbits is correct we can only conceive of them as travelling on till they approach 6ome distant sun which, like ours, first attracts them, and then fends them off by a repulsive force which subsequently comes into action. It does not seem, improbable, however, that in some oases they. may be captured and eventually travel in a closed orbit around another sua.

In conclusion I may again refer to H ALLEY'S COMET, which has somewhat disappointed us by not appearing in transit across the sun's disc. It was watched for by the writer during several days, but nothing but ordinary sunspots were visible. A number of photographs were obtained from the 16th" to the' 21st. and sul-sequ-ently these were carefully scrutinised. The spols travelled across in their usual manner, indicating the sun's axial rotation, but no other object is shown. As an error of a i'- iv minutes of arc in the calculated declination of the comet might account for its' non-appearance at midday, it was

■•ought in* the 'west during the evening: a?ain nothing was seen, "The following morning, Friday, the eastern sky was again scanned, and a faint light, resembling the tail, but shorter and wider, was noted, but the air not beine perfectly cknr trw observation was net published. The watching of the sun's diso was resinned a littl-3 later, and continued driving the day. On May 2,2 the comet was re-observed -> ■ > west through an opening between clouds.

THE MOON. The Moon s phases will' be as follows: — d. h. m. Last quarter , 1 9 54 a.m. N ew moon 8 0 46 a.m. First quarter 15 3 49 a.m. Full moon 23 7 42 a.m. Last quarter 30 4 9 p.m. Perigee 6 3 6 p.m. Apogee ... 18 6 36 p.m.

h. d Tn. Altitude, Ji piter .w 7 50 56 ... N. 44.42 Beta Crucis ... ... 8 M 7 ... S. 76.37 Spica ... 8 52 1 ... N. 54.52 Beta Centauri 9 28 57 ... S. 75.52 Areturns 9 42 59 ... N. 24.32 These times are calculated for the meri-