48 



KNOVVLKDGE & SCIENTIFIC NEWS. 



I February, 1907. 



The Face of the Sky for February. 



By VV. SiiACKLETON, F.K.A.S. 



The Sun.— On the ist the Sun rises at 7.42 and sets at 

 4.46; on the 2Sth he rises at 6.51 and .sets at 5.35. 



Sun-spots may occasionally be observed, thouj^h they 

 are not very numerous; solar activity appears to be 

 diminishing, though at the time of writing there is a 

 large scattered group visible. 



■Phe position of the Sun's axis and of the centre of 

 the disc is shown in the following table : — 



OCCULTATIONS :- 



The Planets.— Mercury (Feb. i, R.A. 20" 55""; 

 Dec. S. 19° 35' ; Feb. 28, R.A. 23*= 46"" ; Dec. S. 0° 9') 

 is in superior conjunction with the Sun on the 2nd and 

 hence during the early part of the month is unobserv- 

 able. Towards the end of the month the planet is an 

 evening star in Aquarius and Pisces setting at 6.38 p.m. 

 on the 20th and at 7.20 p.m. on the 28th. 



Venus (Feb. i, R.A. i7'» 39m; Dec. S. 19° 23'; 

 Feb. 28, R.A. 19" 38-" ; Dec. S. 19° 30') is situated 

 in Sagittarius and is a conspicuous object in the morn- 

 ing sky, rising at 4.38 a.m. on the ist. The planet is 

 at greatest westerly elongation of 46° 53' on the gth 

 when it rises at 4 43 a m. ; on this date the telescope 

 appearance is that of "half moon" -5 of the disc being 

 illuminated. 



Mars (Feb. i, R.A. i^"" 43" ; Dec. S. 18° 49' ; Feb. 28, 

 R.A. 16'' 47"; Dec. S. 21" 51') is situated on the con- 

 fines of Libra and Scorpio and rises about 2.30 a.m. on 

 the 14th. The apparent diameter of the planet is in- 

 creasing as the opposition, which takes place in July, 

 approaches. 



Jupiter (Feb. i, R.A. 6^ g'" ; Dec. N. 23° 25' ; Feb. 28, 

 R.A. 6'' 41" ; Dec. N. 23° 29') is a very conspicuous 

 object in the evening sky and is describing a short retro- 



grade"path near7the]star v Geminorum. On^ the 25th 

 ihe planet is at the stationary point. Throughout the 

 month the planet is well placed for easy observation in 

 the evenings, being due South at 8.30 p.m. on the 14th. 



The equatorial diameter on the 15th is 42"-y, whilst 

 the polar diameter is 2"-8 smaller. On the evening of 

 the 22nd the Moon is in conjunction with the planet at 

 6.37 p.m. 



The following table gives the satellite phenomena 

 visible between 6 p.m. and midnight : — 



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

 " Oc. R." its reappearance ; " Tr. I." the inj^ress 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 ; " Ec. D." denotes disappearance of Satellite 

 by Eclipse, and " Ec. R." its reappearance. 



Saturn (Feb. i, R.A. 23^ 2"^; Dec. S. 8° 14'; 

 Feb. 2S, R.A. 2311 13™ ; Dec. S. 7° o') is only observ- 

 able for a short time after sunset, as he sets at 7 p.m. on 

 the 14th. The ring, as seen in the telescope, appears to 

 be nearly closed and we almost have an edge view; the 

 northern surface of the ring is visible at angle of only 

 3'-^ to our line of vision. 



Uranus (Feb. 14, R.A. 18^ 48-"; Dec. S. 23° 18') 

 is a morning star, rising about 6 a.m. at the beginning 

 of the month. 



Neptune (Feb. 14, R.A. 6" 44™ ; Dec. N. 22° 10') is 

 situated in Gemini not far from the star 36 Geminorum. 

 On the 14th the planet is due South at 9.15 p.m. 



Meteor Showers : — 



Algol may be observed at minimum on the 9th at 

 10.3 p.m., and on the 12th at 6.52 p.m. 



Double Stars.— Casloy, separation 5"-6, mags. 27, 

 37. Excellent object for small telescopes. The brightest 

 pair to be observed in this country ; can always be relied 

 upon as a good show object. 



K Geminorum, separation 6"-3, mags. 4, 8'5 ; very 

 pretty double. 



j- Cancri, separation i"-i, 5"-i, mags. 5-5, 6-5, 7-5 ; with 

 small telescopes the widtr component is readily seen. 



V Draconis, separation 6i"7, mags. 4-6, 4-6 ; a pretty 

 and easy double, can be separated by observing with a 

 pair of opera glasses. 



