THE FACE OF THE SKY FOR MAY. 



By A. C. D. CROMMELIN, B.A., D.Sc, F.R.A.S. 



Table 21. 



Date. 



Greenwich 

 Noon. 



May , 



„ 6 



ii ii 



,, 16 .... 



, 21 



,. 26 



.. 3 1 



Su 

 R.A. 



Dec. 



h. m. 



2 30-5 

 249-6 



3 9'° 

 328-7 

 348-6 



4 87 

 4 29-0 



N.i 4 -8 

 16-3 

 ■7"7 

 18 g 



2D"0 

 2I'0 



N.2I-8 



Moon. 

 R.A. Dec. 



h. m. o 



16 i8"o S. 26*3 

 21 23-3 S. 15-7 

 1 9-8 N.I2'0 

 5 15-8 N.2 7 -s 

 9 33-6 N.14'5 

 13 44-7 S. 15-9 

 19 9-6 S. 25-4 



Mercury. 

 R.A. Dec 



2 29-6 N.14-5 



3 "'6 >8'5 



3 54-4 21-8 



4 35'4 *4'i 



5 " 2 '5 25'3 



5 44 '3 2 5'° 



6 9-6 N.25'2 



Venus. 

 R.A. Dec. 



h. m. o 



O 22"! N. 0"6 



44-2 2-9 



1 64 5-1 

 1 28-7 7'4 



1 5i'3 9'6 



2 14*2 1 1 '7 

 2 37'5 N-"3'7 



Jupiter. 

 R.A. Dec. 



h. m. 



23 24"2 



23 277 

 23 31-1 

 23 34 '4 



23 37'4 

 23 40-3 



23 43'° 



5"o 

 46 

 4'3 

 3 '9 

 36 

 3 '3 

 3' 1 



Saturn. 

 R.A. Dec. 



in. 



h 



5 SS'3 



5 57'5 



5 59 - 8 



6 2*2 



6 4-8 



6 7-3 



6 10 'o 



N.22'7 



22"7 

 22*7 

 22*7 

 22*7 

 22 7 



N.22'7 



Uranus. 

 R.A. Dec 



21 12*7 S.i6'8 



21 13*0 16*8 



21 132 168 



21 i3'3 i6"3 



2i 13*4 i6'8 



ai 13*3 i6'8 



21 13*2 S.i6*8 



Neptune. 

 R.A. Dec 



h. m 



759*2 N.20*3 



7 59"5 



7 59'8 



8 0*2 

 8 0*7 

 8 i*i 

 8 i*7 



20*3 

 20 *3 



20"2 



20 "2 



20 '2 



N.20*2 



Table 22. 



P Is the position angle of the North end of the body's axis 

 measured eastward from the North point of the disc. B, L 

 are the helio-(planeto-)graphical latitude and longitude of the 

 centre of the disc. In the case of Jupiter System I refers to 

 the rapidly rotating equatorial zone, System II to the tem- 

 perate zones, which rotate more slowly. To find intermediate 

 passages of the zero meridian of either system across the 

 centre of the disc, apply to Ti T 2 multiples of 9 h 50 m -6, 

 9 h 55 m -7 respectively. 



The data for the Moon and Planets in the Second Table 



are now given for Greenwich Midnight, i.e., the Midnight at 



the end of the given day. 



The letters m, e stand for morning, evening. The day is 

 taken as beginning at midnight 



The Sun is moving Northwards at a slackening pace. 

 Its semi-diameter diminishes from 15' 54" to 15' 48". Sunrise 

 changes from 4" 36 m to 3 n 52 m ; sunset from 7" la™ to 8 h 4 m . 

 The Sun's surface is likely to repay careful scrutiny, owing 

 to the recrudescence of activity. 



Mercury is in superior conjunction with the Sun on 1st; 

 then it is an evening star, well placed for observation. East 

 Elongation, 23° from Sun on 31st. Semi-diameter increases 

 from 2k" to 4". Illumination diminishes from Full to g. 



VENUS is a morning star. Illumination increases from 

 | to ?. Semi-diameter diminishes from 6\" to 6". 



The Moon.— Last quarter 6 d 5 h 23 m m. New 14 d 3 h 5\ m tn. 

 First quarter 22 d 4" 50 m m. Full 28" 9 b 55™ c. Apogee 



14 



respectively. Maximum librations 6" 7° W., 14" 7° S„ 22" 8" E., 

 27 7° N. The letters indicate the region of the Moon's 

 limb brought into view by libration. E., W. are with 

 reference to our sky, not as they would appear to an 

 observer on the Moon (see Table 24). 



Mars is still badly placed, near Venus on 14th. 



Jupiter was in conjunction with the Sun on Feb. 24th, 

 and is still difficult to observe. Equatorial diameter 36", 

 Polar 34". 



Configurations of satellites at 3 h 30™ a.m. 

 Jupiter's Satellites. 



The following satellite phenomena are visible at 



Greenwich, all in the morning hours : — l d 3 h 30 m I. Oc. R ■ 



14 d 3 h 59™ 51* I. Fc. D. ; 16 d 2 b 30 m I. Tr. I.. 3 h 36™ I. Sh. 



I.; 21 d 3 h 44™ II. Tr. I.; 23 d 3 h ll m I. SIi. I. ; 24 d 3 h 55 m 



d 9 h e. Perigee 28 6 e, semi-diameter 14 43 , 16 46" |, Qc. K. ; 2S' 1 3 b 47 m II. Sh. I.; 31 d 2 b 16*° 35' 1 Ec P 



The Northward motion of Jupiter will make this year's 

 opposition (which ocean on September 17th* mote favourable 

 for European observers than those of the last four years, in 

 which it has been verv low down. 



121 



