ASTRONOMICAL NOTES

Evening Star, Issue 22351, 29 May 1936, Page 12

ASTRONOMICAL NOTES

THE SKIES IN JUNE [Written by A. G. C. Crust, M.Sc., for the ‘ Evening Star.’] POSITIONS OF THE STARS Local sidereal time, 14.1 i; latitude, 46i«eg S. The following star positions hold good locally four minutes earlier each evening, as at 9.30 p.m. on June 2, 8.30 p.m. on June 17, and 7.30 p.m. on July 2. Achernar now shines due south, at an elevation of 14deg, while Alpha Crucis is SIW. by S., 67deg., and Canopus, in the same direction, 18deg. Regulus is now N.W. by W., 12deg.; Spica, N.N.W., 64deg.; Arcturus, N, 24deg; Antares, E.N.E.. 56deg; and Alpha Centauri, S. by E., 75deg, the highest bright star. The Moon will pass 3deg north of Spica on the afternoon of June 1, and her position at 9.30 p.m. on June 2 will be N. by E., 62deg. She will pass Antares on the morning of the sth, full moon occurring the same afternoon, and a conjunction with Jupiter on the morning of the 6th. At 9.10 p.m. on June 7 the Moon will be E. by S., 34deg, last quarter will occur at midnight June 12-13, a conjunction with Saturn on the forenoon of the 13th, and one with Mercury on the 18th. New moon, falling on the afternoon of the 19th, will cause a total eclipse of the Sun, the belt of totality commencing in Greece and passing across Asia, mostly through Soviet territory, and ending near the Japanese island of Yesso. A partial eclipse will be visible over the remainder of Europe and Asia. On the forenoon of June 24 the Moon will pass Regulus, first quarter will occur on the forenoon of the 27th, and the Moon’s position at 7.50 p.m. that evening will be N.W. by N., 49deg. Winter begins at 2 a.m. on June 22, when the Sun is overhead on the Tropic of Cancer.

The planet Mercury will pass 3deg north of Venus on the evening of June 5, will be stationary in the morning sky on the 12th, and at greatest elongation west on June 25.

The planet Venus will pass Mars on June 20, and be in superior conjunction with the Sun on the 29th.

_ The planet Mars will be in conjunction with the Sun on June 11.-

The planet Jupiter will be placed E. by N., 44deg to 46deg., at' S.T. 14h. He will be in opposition to the Sun on June 10, this _ opposition, and that of next year, being the most favourable possible for observation in New Zealand.

The superior conjunctions of Jupiter’s satellites occur as follow: —lo, first, June 1:23:05, seventeenth, June 30:06:00; Europa, first, June 1:18 ;08, ninth, June 30:03:12; Ganymede, first, June 3:03:37; fourth, June 24:13:26: and Callisto on June 3:08:50 and 19:23:03. Ganymede will be at greatest elongation west on Mondays, and greatest elongation east on Fridays, Callisto will reach west elongation on the 15th. and east elongation on June 7 and 24.

The planet Saturn may be seen in the early morning sky. From the Queen’s Gardens, Dunedin, at 14h S.T. Spica will appear rather high over Burlington street, Arcturus father low over First 'Church, Achernar low in the opposite direction, and Antares rather nigh over the Early Settlers’. Hall. At 9.10 p.m. on June 7 the Moon will shine up Rattray street from a moderately low altitude.

CONSTELLATIONS OF THE SOUTH CIRCUMPOLAR ZONE

VII., VIII., PUPPIS, THE STERN, AND YOLANS, THE FLYING FISH. The remaining portion of the ship Argo, within the South Circumpolar Zone,_ is the southernmost part of Puppis, the Stern. Almost due south if it, and bordering on Carina, is the small constellation whose full name is Piscis Volans, the Flying Fish, but which is generally known simply as “ Volans.”

The portion of Puppis in the South Circumpolar Zone contains one star of the third magnitude, called Tan.Puppis, of mag. 2.8 and type KO, in the square 84, 54. It is yellow in colour, and has

a spectroscopic companion revolving in a period of 1,066 days at a distance of 3.7 times that of the Sun from the Earth. The light of Tau, takes 130 years to reach us, the temperature of the primary of the system being 3,600c1eg, and its diameter about 44 times that of the Sun. The sunpower of the system is 120. There are also four stars of the fourth magnitude'. I. Pup., in the square 87,59, of mag. 4.5 and type FO, is 73 light years distant, pale blue in colour, and eight times as bright as the Sun, but only 1.6 times as wide. Its surface temperature is 7,770 deg absolute. Next comes the distant but very bright star R. Pup., of mag. 4.3 and type 81, the light of which takes about 1,000 years to travel to our eyes. It is a blue star of sunpower 1,900, its colour indicating a surface temperature of 10,800 deg and a diameter 16 times that of the Sun. Its colour' may have been, reddened somewhat, however, by passage through thin calcium clouds during its long journey. Its zone position is 83,65. Our nest star, V. Puppis, is a famous eclipsing binary, the light from which takes at least 13 centuries to reach us, and so is as old as Islam. Its maximum magnitude is 4.1 ; but it reaches 4.8 at the primary minimum,; and also shows a deep secondary minimum. Its period is 1.45 days, and a study of its variations shows that thq diameters of the two stars are 8.45 and 7.70 times that of the Sun, and that they revolve almost in contact, the relative velocity being 380 miles per second! Their sunpowers are 1,740 and 1,580, and their temperatures must be about 20,000 deg. The colour, however, is so pale as to indicate about 10,300 deg, so that some reddening during its long journey through space is indicated. The zone position of V. Pup. is 81,65. In the square 85,65 may be mapped P. Pup, of mag. 4.25 and type 80, distant 800 light years and having a sunpower of 1,100. Its blue colour indicates a width 9.3 times that of the Sun and a temperature of 13,300 deg. Volans, the Flying Fish, contains six stars of the fourth magnitude. Gamma, in the square 64,51, is a wide double of mags. 5.8 and 3.9, types GO; and KO, with a common proper motion and 14sec of arc apart, indicating a real separation over 540 times the distance from the Sun to the Earth. The sunpowers are 6 and '3B, the brighter star having a temperature of 4,BBodeg and a diameter 10.2 times that of the Sun, the distance from the Earth being 125 flight years. Delta, in the square 67,53, is a star of very great but uncertain distance. Its magnitude is 4.0, and though its type is F 5 its colour is pale yellow. Zeta, of mag. ,3,9 and type KO, in the square 61,53, is distant 120 light years and is 32 times as bright as the Sun, with a temperature of 4,160 deg and diaiiieter 15 times that of the Sun. In the square 64,57 may be mapped Epsilon, of type B 5 and mag. 4.6, a spectroscopic binary with a period of 14.2 days. The companion shows no spectrum, and is distant 20 million miles from the primary. The light from Epsilon takes three centuries to reach us, and the sunpower of the system is 120, the probable temperature and diameter of the primary being 14,200 deg and 2.7 times that of the Sun. There is an eighth magnitude companion at a distance of 6sec of arc. Beta Vol., in the square 65,60, of mag. 3.6 and type KO, is a _ giant star 130 light years away, 51 times as bright as the Sun and 37 times as wide, with a temperature of 3,460 deg. Lastly, Alpha, of mag. 4.2 and type A 5, is'a pale blue star 69 light years distant, with sunpower 9.1, the radial velocity being variable. The:' temperature of the primary is probably B,soodeg, and its diameter 1135'0f that of the Sun. The zone position of Alpha is 62,63. The six stars of Volans form a group with some resemblance to a fish not far from Beta Carinae. The genitive form of the name is “ Volantis ” and the contracted form “ Vol.’.’