^4 



KNOWLEDGE & SCIENTIFIC NEWS. 



[January, 1907. 



The Face of the Sky for January. 



By W. Shackleton, F.R.A.S, 



The Si'N. — On the ist the Sun rises at 8.8 and sets at 

 3.50; on the 31st he rises at 7.44 and sets at 4.44. 



The earth is nearest the Sun on the 2nc1, when the 

 Sun attains his ma.ximum apparent diameter of 32' 35". 



Sun-spots are not very numerous, thou<;li an occasional 

 group may be obferved on the solar disc. 



There will be a total eclipse of the Sun on the 14th, 

 invisible in this country, but visible in Central Asia as a 

 total eclipse, and in India as a partial one. 



The positions of the Sun's axis and of the centre of 

 the disc are given below : — 



There will be an eclipse of the Moon on the 2gth, but 

 it is invisible in this country. 



OCCULTATIONS : 



The Planets. — Mercury (Jan. i, R.A. 17'' 25""; 

 Dec. S. 22° 50' ; Jan. 31, R.A. 20'' 48m ; Dec. S. 20° 2') 

 is a morning star in Scorpio during the early part of the 

 month. The planet is not well placed for observation, 

 and towards the end of the month is out of range, as he 

 is approaching superior conjunction with the Sun. 



Venus (Jan. i, R.A. 16'' 3"> ; Dec. S. 16° 21'; 

 Jan. 31, R.A. 17'' 35'"; Dec. S. 19° 17') is a morning 

 star in Scorpio rising at 4.40 a.m. on the 4th ; on this 

 date the planet is at greaicst hriUiaitcy. The telescope 

 appearance is a thin crescent, 0-35 of the disc being 

 illuminated en the 15th. 



Mars (Jan. I, R.A. 14'' 28"; Dec. S. 13° 33'; Jan. 31, 

 R.A. 15'' 40"; Dec. S. 18" 41') is a morning star, in 

 Libra, rising at 2.47 a.m. on the 15th. The apparent 

 diameter of the planet is increasing, being about 5"\5 ; 

 this, however, is still too small for useful observation 

 with telescopes of moderate power. 



Jupiter (Jan. i, R.A. 6'' 24™ ; Dec. N. 23° 15'; Jan. 31, 

 R.A. 6^ 9™ ; Dec. N. 23° 25') is very favourably placed 

 for observation in the evening, rising at 2.23 p.m. on 

 the 15th, and being due South at 10.39 p.m. 



The bright moons can be seen in very small telescopes, 

 or even in a pair of binoculars magnifyirg 6 or 8 times. 



On the evening of the 2r)th the Moon will appear near 

 the planet. 



The equatorial diameter of the planet on the 16th is 

 45"'9. whilst the polar diameter is 3"-o smaller. 



The following table gives the satellite phenomena 

 visible between 8 p.m. and midnight: — 



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

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

 and "Tr. E." its ef^ress ; " Sh. I." the ingress of a transit of the sliadow across 

 tile disc, and " Sh. E." its egress; " Ec. D." denotes disappearance of Satellite 

 by Kclipsf. and " 1-x. R." its reappearance. 



Saturn (Jan. i, R.A. -2.2'^ 511"; Dec. S. 9° 25'; 

 Jan. 31, R.A. 23I1 im ; Dec. S. 8" 17') is getting more 

 to the west, and observations are only possible in the 

 early evening. On the 15th, the planet is due south at 

 3.20 p.m. and sets at 8. 38 p.m. The ring, which can 

 be seen in small telescopes with moderate powers, 

 appears to be gradually closing up ; we are looking on 

 the northern surface at an angle of only 5". 



Uranus (Jan. 16, R.A. 18'' 42™ ; Dec. S. 23° 25') 

 was in conjunction with the Sun on the 31st of last 

 month, and hence is unobservable. 



Neptune (Jan. 16, R.A. 6" 47""; Dec. N. 22° 6') being 

 in opposition to the Sun at the early part of the month, 

 is on the meridian at midnight. The planet is situated 

 in Gemini, not far from the star 36 Geminorum. 



Meteor Showers: — 



Minima of Algol may be observed on the 17th at 

 1 1. 31 p.m., the 20th at 8.20 p.m., and the 23rd at 5.9 p.m. 



Ceti (Mim) is unusually bright at this maximum, being 

 equal in magnitude to a Arietis (2-1), nearly a fortnight 

 before the computed date of maximum. Observations 

 should be continued to determine the date of maximum 

 and rate of diminution in brightness. 



Telescopic Objects : — 



Nebula. — Orion Nebula, situated in the sword of 

 Orion, and surrounding the multiple star e, is the finest 

 of all nebulrc ; with a 3 or 4 inch telescope, it is best 

 observed when low powers are employed. 



Double Stars. — ^ Orionis (Rigel), mags, i and g, 

 separation 9". On account of the brightness of the 

 principal star, this double is a fair test for a good object- 

 glass of about 3-inch aperture. 



5 Orionis, mags. 2 and 7, separation 35"; easy double. 



i' Orionis, triple, mags. 3, 6, and 10, separation 2"*5 

 and 56"; rather difficult in a 3-inch telescope. 



X Orionis, mags. 4 and 6, separation 4"-5 ; pretty 

 double. 



0- Orionis, triple, mags. 4, 8, and 7, separation i2"-5 

 and 42". 



