ROUGH ASTRONOMICAL NOTES

Evening Star, Issue 3906, 31 August 1875, Page 2

ROUGH ASTRONOMICAL NOTES

Sktobmber, 1875,

1. The Sun "crosses the line," or, as astronomers say, be entere Libra at about midnight on the 23rd, and spring commences. An eclipse of the Sun will take place n the 30tb, but it will be invisible here. But few sunspots have been visible during the past month, but on Saturday last a group of three and one isolated spot were to be seen. The group was near the centre of the disc, the three forming a line, with the largest in the middle. Thia was a double spot of moderate Biae; it appeared to be undergoing rapid changes—in the morning its duplicity was hardly perceptible, but in the afternoon a well-defined "bridge" stretched right asross the middle of the spot. These marvellous changes in the solar photosphere, extending as they do over so many thousands of miles, and taking place within such brief intervals of time, are probably the most astounding phenomena that oome under the notice of the astronomical observer. 2. The Moon will be at her greatest distance from the Earth on the 7th, at about one o'clock in the afternoon, and at her least on the 19th at the same hour. The phases will take piace aB follows : First Quarter on the Bth, at 9hrn. Bmin. a m Full Moon on the 16th, at Ohrs. 12min. a.m Last Quarter outlie 22nd, 6his. 30min p m New Moon on the 26th, at Ohrs. 25min. am"

The tiles may be expected to be hisjh both at new moon and at fu Imoon, owing to tha proximity of both tho Sun and Moon to the equator, but as the perigee takes place this month poon after full moon, the tides will probably be highest and lowest just after the full. It Bhould be remembered that in places like Dunedin aud Port Chalmers, situatod on an arm of (he sea, local causei have a very great influenco on the tide* A strong wind blowing down the bay, for In stance, would of course prevent a "tide from being high ; but, other things being equal, exceptional tides may be expected at the periods named.

3 Mercury will be favorably Rituated for observation during the latter half of the present month. On the evening of the 24th he will be .ibout a degree aud a-half east of the star Spica. tormina an elongated triangle *ith Jupiter and that star. On the 30ih of the montli Mercury wdl set 2hrs. 5,, in. after the Bun. \s the twiiight is short at this time of 'he year, it will probably be possible for observers to get a good view of this "difficult" planet at about the date mentioned. At this time it will bu at no gieat distance from Jupiter, which will follow it nineteen minutes, about ljdeg. N. Mercury's npid twinkling will m.kn him a striking contrast to his steadily shining neighbor.

4. Venus is now lost in the rays of the Sun. >he will be in superior conjunction on the •2Srd, after which she will bu an evening star but she wiU not be visible without the aid of a telescope for many weeks.

5. Mars is fast waning. He is no longer an objeot of great interest, though p-etty satisfaotory viewH of bis markings may sometimes be obtained. Fie in still in Sa-iltarius, but is beginning to move pretty rapidly towards tli« east among the stars. He passes the meridian at 7.30 p.m., and sets at 3.43 a.m. At about mi-might of the 10th the Muou will pass close to Mars, the planet being N. 6. .Jupiter is now fist approaching the Sun aud will soon be gone for the season. He is now fast moving towards the east, and will soon be in the constellation Libra. He sets at 10 p.m.

7. Saturn him returned to the constellation Capricorn; he is now just north of the star Delta of that constellation, and almost exactly in the line which joins the star Altair in the Lagle, with lomalhaut in the Southern Fish. Hemes at 3.54 p.m., passes the meridian at 11.4 p.m., and sets at 6.14 a.m. Saturn is at present just past the opposition, and is a beautiful object in a large Urge telescope. _ At present an BJin speculum shows the principal division between the rinun the azure blue of the poles, a cinnamon-colored band south of the Equator, and on or near the Equator a bright band like polished silver • in very good weather it shows the inner ring,' C £ P £ V fl aU , roimd ' *?^ }t > of c °™« at the back of the planet; also eaveral mark ings like concentric scratches in the principal rings, aud, finally, it Bhows six satellites a telescope of moderate aperbme-say Sin-onpht now to show two satellites, and, in first-cfasl

ttMtfatf.tbM* evputeff law. Ift iftoaH ■how distinct traow of til* principal division In th« rings, and it should also show the crape veil aa a slate* oolored line whore it passes over the planet. It sheuld also make it manifest that the planet has bolts, though it could not be expected to show them ve>y distinctly. It ought to show, too, a remarks bio dark belt which has made its appearance dining the present seHsyn. This belt is in the cinnamon-colored w>n< j before referred to. Any pood telescope of the aperture stated would >how all these details, and more, if the weather is fine enough to allow a high power to be used. At all events our three-inch equatorial does so. 8. Uranus.- Unfavorably situated.

y. Neptune will bo in opposition next month, when we shall give particulars as to the bwt way of "fishing him up."