ASTRONOMICAL NOTES FOR MAY.

Marlborough Express, Volume XLII, Issue 102, 1 May 1908, Page 6

ASTRONOMICAL NOTES FOR MAY.

The SUN is in the constellation Aries till the ISth, _ -when he enters Taurus. His declination increases ■! northward by about 7deg; during the month, and his altitude,at noon decreases by the same amount during " this period. The rapid diminution xii the arc described by the sun in the northern sky becomes strikingly apparent at this time of year, and the shorter period of sunshine follows as a necessity. Sun spots h.ave been again fairly plentiful duringxthe earlier paift of the month,- when several fine groups were observed upon the solar disc. The MOON, in her monthly circuit of the heavens, comes into the vicinity of the planets and some of the brighter stars, and serves as a convenient pointer to them. She will be near Mars or. the 3rd, Venus on the 1 evening of the 4th, Neptune on the early morning of the 6th, Jupiter on the evening of the 7th, fairly close to the north, Uranus on the evenings . of the 19th and 20th (when the moon will pass very close to the planet on its southern side), Saturn on the 25th, but too near the sun to be observed to advantage. She will be passing through the following constellations during the early- evening on the dates given : —New on the Ist of the month, and in the constellation Aries, from which she will emerge ' and become visible as a crescent on the '3rd in the constellation Taurus, and loav down under the Hyades and the bright red star Aldebaran. From the 4th to the 6th', she will be in " Gemini, and close to the Twins—Castor and Pollux—on the latter date; Cancer on the-7th and Bth; Leo on " the 9th and 10th, and nearest to the bright Regulus on the 9th; Virgo from the 11th to the 14th, and nearest the star Spica on the 13th; Libra on tho 15th,and 16th; Scorpio on the 17th and 18th, and near the brilliant red Antares on the 17th; Sagittarius on the 19th and 20th, -and Capricornus en the 21st to the 23rd, after which she rises latei . Phases of the Moon in New Zealand, mean time: —

MERCURY is a morning star at the beginning of the month, but too close to the sun to be visible; he will move towards, and, pass through superior conjunction on the Bth, after which he will be aiji evening star throughout the montii. ? but too near ' the sun to be well seeny; with his great northern depression at'this time, but •nay be glimpsed at t^he end of the month. He will be in. his ascending node on. the Bth, in perihelion on the 12th, and ,111 greatest heliocentric latitude north on thfe 23rd. " VENUS is an evening star m Taurus, and moving forward rapidly to the east amongst the stars of that constellation. She is a most brilliant object m our evening skies, but rather low down towards the north-west, owing to her great northern declination of over 27 degrees. She will be 111 conjunction with the moon on the 4th, and should appear at tier brightest on the night of the 30th. She' is a fine telescopic object at this time, and will appear to greatest advantage if viewed some time before sunset, before she reaches • the # disturbances so noticeable in all objects when nearing the horizon. MARS is an evening star in Taurus, and' moving easterly in that constellation. He is now too near the sun. for useful observations, but it may be an exercise for some of our 'star-gazers to look for him on the 3rd, when he will be in conjunction with the moon, and about four times . the diameter of. that body, distant from her at the time. JUPITER, is an evening star in the constellation Cancer, and by far the most brilliant object in our evening skies after the setting of Venus. Though past opposition, fine views of his surface markings—the -"Belts i — may be had, and much of his satellite phenomena observed before he reaches his setting. He will be -in conjunction ' with the. moon on the > evening of the 7th, when he will appear to be rather more than three diameters away to the south of that %ody. Interesting eclipses, transits, or occultations of these bodies may be seen on the following dates, and between sunset and his setting:—2nd, 3rd, sth, 7th, Bth; 9th, 10th, 16th, 17th, 18th; 23rd, 24th, 25th, 27th, and 31st. " SATURN is now a morning star in the constellation Pisces, having a forward movement throughout the month. He may now be caught by the observer working before sunrise, when good opportunities may be had for the observation of his fainter "satellites, now that his ring system is so nearly in our plane of vision. He will be in conjunction yith the moon on the evening-of the 25th, and may be seen on either side of this body on the 24th and 25th insts. respectively. ; -..,-■" , URANUS is an evening star in Sagittarius, retrograding amongst the stars during the month. He will be in conjunction with the moon ~on the 20th of the month.

NEPTUNE is an evening star in Gemini; moving forward amongst the stars during the nionth. He will be in conjunction with the moon on- the 6th, 1.3 degrees to the south. J METEORS may be seen on the -mornings of the 17th, 18th, and 21st; in the constellations Pegasus, Hercules, and Aquarius. ' The CONSTELLATIONS for the middle of* the month at about_ eight o'clock are as follows:—North: Crater and Corvus high up on the Water Snake (Hydra); Virgo lies dose up to the east, and Leo to the • west of the meridian, with Coma -. Berenices and Leo Minor underneath these. Bootes and the fine star Arcturus are in jbh'e north-east, with Serpens, Ophinchus, and/Libra to the, east. East and south may be seen the Scorpion, followed by Sagittarius, with the Centaur high overhead, the two Pointers, Alpha and Beta, with the Cross, being now near their/ highest point. On tlfe southern horizon is Achernar, with the Toucan and Indian ■, with Pavo—the Peacock— above them. In the south-west is Columbia, with Canis Major and the brilliant Sirius, getting down . towards tlie horizon, Argo standing above these, and the bright star Canopus working down towards his winter position, near the southern horiThe discovery of Jupiter's eighth satellite does not come altogether as a surprise to the astronomical world, but we rejoice in the fact that this satellite has fallen a prize to one of our.-- countrymen. One interesting feature in regard to this discovery is that it was made at an observatory (Greenwich) -supposed by many to suffer all the disadvantages of. a position minus those qualities that are looked for nowadays in tv? selortion qf a site for an astronomical obsei •

vatory. The chief of these is a lofty elevation and distance from the smoke of great cities, and Greenwich can scarcely be held exempt from thes,e prime defects; yet periods of really good observing conditions must be obtained at that station, as witness the visual observation of one of the miniature satellites some short time back by Mr Xhristie and 'some visiting American astronomers._ The history of Jupiter's satellites is briefly as follows:—The four principal moons fell a prize to the great Galileo, and his primitive telescope, in January of the year 1610, when the motions around the giank pla.net were considered to be the strongest visible demonstration of the truth of the Copernician theory of the solar Ej'stem. For nearly three hundred years these four were the Qnly known attendants on ihe great planet. Then cams the discovery, by Professor Barnard, of the "Lick Observatory, of a most miniature body, not exceeding IQO wiles in diameter, and by som", measurps mado less than half this amount. Then followed, in 1904, Dr. Perrine's discovery of the Oth and 7th moons, which were caught upon the photograph plate exposed in the great " Crossley" reflector of, the above ob&'ervatory.' It may be almost taken as a matter of course that this latest addition to Jupiter's family has left'his trail upon the sensitised film exposed in tho focus of one of those fine telescopes at the disposal of the Astronomer Rojal at Greenwich, and that it. will be altogether beyond the roach of any but the few laigest telescopes in. tho vorld.

THE HON. DIRECTOR, Wanganui Observatory May Ist, 1908.

, D. H. M. New Moon 1 3 a.m. First Quarter 8 10 53 p.m. Full Moon 16 3 2 p.m. Last Quarter 23 11 47 a.m. New Moon 30 2 44p.m.