338 



KNOWLEDGE & SCIENTIFIC NEWS. 



[January, 1906. 



The Face of the Sky for January. 



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



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

 3.59 ; on the 31st he rises at 7.44 and sets at 4.45. 



The earth is nearest the Sun on the 3rd, when the Sun 

 attains his maximuin apparent diameter of 32' 35". 



Spots are numerous, whilst prominences as shown by 

 recent spectroscopic observations are particularly active. 



The position of the Sun's axis and equator is shown in 

 the following table : — 



Apogee 

 Perigee 



OCCULTATIONS :- 



Angle I Angle : Age. 



BroniN. Mean ifromN 

 point. Time. 1 point. 1 



Jan. 



J- Ceti . . . . 

 B.A.C. 1526.. 

 " Leonis 



5-S 6.53 



11.58 



207- 

 230° 

 264° 



The Planets. — Mercury (Jan. i, R.A. i/h y™ ; 

 Dec. S. 20° 35'. Jan. 31, R.A. 19'' 57"' ; Dec. S. 22° 17'j 

 is a morning star in Sagittarius, and is at greatest 

 westerly elongation on the 4th, when he rises about 

 6-15 a.m. This elongation is not a very favourable 

 one. 



Venus (Jan. i, R.A. 17^ 59ni ; Dec. S. 23° 26'. 

 Jan. 31, R.A. 2o'> 40™ ; Dec. S. 19" 28') appears in close 

 proximity to the Sun, and is practically unobservable. 



Mars (Jan. i, R.A. 22i>24-"; Dec. S. 11'' 2'. Jan. 31, 

 R.A. 23'' 48'"; Dec. S. 1° 50') is an evening star in 

 Aquarius, and appears in the sky a little to the east of 

 Saturn. Near the beginning of the month the planet 

 is on the meridian about sunset, but in consequence of 

 now being at a great distance from the earth he appears 

 but a feeble object. 



Jupiter (Jan. I, R.A. 3h 40m; Dec. N. 18-41'; Jan. 31, 

 R.A. 3^ 36"^ ; Dec. N. 18'' 41') is due south at 8 p.m. 

 near the middle of the month. The planet is describing 

 a retrograde path near the Pleiades, is at the stationary 

 point on the 21st, after which his motion is direct or 

 easterly. The equatorial diameter of the planet on the 

 14th is 45"-o, whilst the polar diameter is 2"-9 smaller. 

 The planet is very favourably situated for observation, 

 and even in very small telescopes his belt-like markings 

 and attendant moons form an interesting object. 



The following table gives the satellite phenomena 

 visible in this country before midnight : — 



' Oc. U." 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." i's egress. 



Saturn (Jan. i, R. A. 22'' 8""; Dec. S. 13° 9'. 

 Jan. 31, R. A. 22'' 20'"; Dec. S. 12° o') is now getting 

 to the west and will soon be out of range ; near the 

 middle the month the planet sets about 7.30 p.m. The 

 northern surface of the ring is presented to us and we are 

 looking upon it at angle of 9°. 



Uranus (Jan. i, R. A. i8h 2i">; Dec. S. 23° 37™) 

 appears in close proximity to the Sun and is therefore 

 unobservable. 



Neptune (Jan. 17, R. A. 6'' 37""; Dec. N. 22° 13') is 

 due south about 11 p.m. near the middle of the month. 

 The planet is situated in Gemini, some 6' east of the 

 star fi Geminorum, but in small telscopes it is difficult to 

 identify among the numerous stars in the same field of 

 view, but he can be detected by his slight motion if 

 observations are made on several successive nights. 



Meteor Showers : — 



Minima of Algol may be observed on the 15th at 

 n.4 p.m., the i8th at 7.53 p.m., and the 21st at 4.42 p.m. 



Ceti (Mira) should be watched, as it will probably 

 reach a maximum during the month. 



Telescopic Objects : — 



Nebula. — Orion Nebula, situated in the sword of 

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

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

 observed when low powers are employed. 



Crab Nebula (M i), in Taurus, situated about i|° 

 northwest of s' Tauri in R.A. 5^ 29"", Dec. 21° 58' N. 



Clusters. — M 37, situated in Auriga, is one of the 

 finest clusters, and very compact, its position is R.A. 

 5''. 46™., Dec. 32° 32' N. 



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

 separation g". On account of the brightness of the prin 

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

 of about 3-inch aperture. 



Orionis, mags. 2 and 7, separation, 53" ; easy double. 



(- Orionis, triple, mags. 3, 6, and 10, separation i^'- and 

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



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



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

 and 42' . 



