394 



KNOWLEDGE & SCIENTIFIC NEWS. 



[March, 1906. 



The Face of the Sky for March. 



Bv \\ . Shackleton, F.K.A.S. 



The Sun. — On the ist the Sun rises at 6.49 and sets at 

 5.37; on the 31st he rises at 5.41 and sets at 6.28. The 

 Sun enters the sign of Aries at i p.m. on the 21st, when 

 Spring commences. 



The solar disc continues to be well marked with sun- 

 spots, and recent spectroscopic observations of the Sun's 

 limb show many active prominences. 



The position of the Sun's axis, equator, and helio- 

 graphic longitude of the centre of the disc is shown in 

 the following table : — 



The Zodiacal light should be looked for in the west 

 for a few hours after sunset. 

 The Moon : — 



■'" OccuLTATiONS : — The following are the occultations 

 of the brighter stars visible at Greenwich before mid- 

 night. 



Tiii. I'l.-vst is.^Mercury (Mar. i, R.A. 2^^^ 16"; 

 Dec. S. 5° 56'. Mar. 31, R.A. i'' o" ; Dec. N. 10° i') 

 is at greatest easterly elongation on the i8th, and should 

 be looked for in the west shortly after sunset for a period 

 of four or five days on either side of the date of elonga- 

 tion. Although the elongation is only i8^°, it is a favour- 

 able one on account of the large angle at which the 

 planet sets to the horizon. 



Venus (Mar. i, R.A. 23'' 2^ ; Dec. S. 7" 44'. 

 Mar._3i, R.A. i'' 19"; Dec. N. 7' 21') is an evening 

 star in .•\quarius, but not well placed for observation. 

 Near the middle of the month the planet sets about 

 half-an-hour after the Sun. 



Mars (Mar. i, R.A. ih 8'"; Dec. N. 7° 3'. Mar. 31, 

 R.A. 2i> 30m; Dec. N. 15'^ 4') sets about 9.20 p.m. 

 throughout the month, and may be observed shortly after 

 Sunset looking west. The lustre of the planet is, how- 

 ever, feeble, as he is at a point in his orbit situated at a 

 great distance from the earth. 



Jupiter (Mar. i, R.A. 3'' 47™ ; Dec. N. 19° 18'; Mar. 31, 

 R..A. 4'' 6"'; Dec. N. 20° 20') continues to be a con- 

 spicuous object in the evening sky; about the middle 



of the month the planet sets shortly after midnight. The 

 planet is now describing a direct or westerly path, and 

 thus he appears to be moving away from his position 

 near the Pleiades towards .Aldebaran. 



The equatorial diameter of the planet on the 15th is 

 37"'2, whilst the polar diameter is 2"-4 smaller. 



The following table gives the satellite phenomena 

 observable before midnight : — 



5 lin. 



I. Tr. I. 



I. Sh. I. 



I. Oc. D. 



in. Tr. E. 



I. Ec. R. 



I. Tr. E. 



I. Sh. E. 



IL Ec. R. 



I. Oc. D. 



II. Tr. I. 



I. Sh. I. 



I. Tr. E. 



I. Sh. E. 



I. Ec. R. 



II. Oc. D. 



III. Ec. R. 



II. Sh. E. 



I. Tr. I. 



I. Sh. I. 



I. Ec. R. 



III. Ec. D. 



II. Sh. I. 



II. Tr. E. 



9 58 



7 16 



8 25 



7 25 



8 35 



8 32 



9 40 

 9 12 

 9 27 

 8 32 



" Oc. D." denotes the disappearance of the Satellite behind the disc, and 

 " Oc. R." its re-appearance ; " Tr. I." the ingress of a transit across the disc, 

 and "Tr. E." its egress ; " Sh. I." the ingress of a transit of the shadow across 

 the disc, and " Sh. E." its egress. 



Saturn (Mar. i, R.A. 22'' 33™; Dec. S. 10° 45'. 

 Mar. 31, R.A. 22h 4711 ; Dec. S. 9'" 28') is a morning Star 

 rising about 6 a.m. near the middle of the month. 



Uranus (Mar. 14, R.A. 18'' 35™; Dec. S. 23° 29') 

 is not well placed for observation ; the planet rises about 

 3 a.m. on the 15th. 



Neptune (Mar. 14, R.A. 6I1 33"; Dec. N. 22'' 18') is 

 due south at 7.7 p.m. on the 14th. The planet is situated 

 about 3" S. and ij' W. of the star e Geminorum, but is 

 difficult to identify among the numerous small stars in 

 the neighbourhood. 



Meteor Showers : — 



Minima of Algol occur on the 2nd at 8.7 p.m., 22nd at 

 9.50 p.rn., and 25th at 6.39 p.m. 



Double Stars. — 7 Leonis, X.^ 15™, N. 20' 19', mags. 2, 

 4 ; separation 5"-S. In steady air, the prime requisite for 

 double star observations, this double maybe well seen in 

 a 3-in. telescope with an eyepiece magnifying about 30 to 

 the inch of aperture, but on most nights one with a 

 power of 40 is better. 



The brighter component is of a bright orange tint, 

 whilst the fainter is more yellow. 



, Leonis, XI.'' 19", N. ii° 5', mags. 4^, 7^ ; separa- 

 tion 2"-5. A pretty double of different coloured siars, 

 the brighter being yellow, the other blue. This object 

 requires a favourable night and a fairly high power on 

 small telescopes. 



a Leonis (Regains) has a small attendant about 180" 

 distant, magnitude 8-3, and easily seen in a 3inch 

 telescope. 



a Canum \"enat. [Coi- Caroli), XII.'' 52"", N. 38° 50', 

 mags. 2-5, 5-5, separation 20"; easy double, can be^seen 

 with moderately low powers, even in 2-inch telescopes. 



