558 
OBSERVATIONS OF PERRINE’S COMET, 1902 6. 
THs comet was discovered by Perrine, using the 12-inch 
refractor of the Lick Observatory, on the morning of 
September 1, and the discovery was published by the following 
telegram, of that date, from Prof. Pickering to the Kiel Cen- 
tralstelle :—‘‘ A comet was discovered by Perrine August 31, 
16h. 8m. 16s. Lick, a app. 3h. 17m. 49s."4, 5 app. + 34° 38’ 
47’, slightly elongated, mean diameter 4’, magnitude 9, 
tolerably well-defined nucleus, tail.” This object was also 
discovered, independently of Perrine, by M. Borelly, of the 
Marseilles Observatory, on September 2, gh. 50m.°4, and the 
observation was forwarded to Kiel in a telegram from M. 
Leewy, which stated that the comet’s position, at the time of 
its discovery, wasa = 49° 9’, N.P.D. = 54° 48’, its daily move- 
ment —15/ and — 26’ respectively, and that it possessed a nucleus | 
and a tail. 
Further observations were made by Perrine, and the follow- 
ing parabolic elements, ephemeris and details have been 
obtained therefrom :— 
Elements of Comet 1902 6. 
T = 1902 November 23°472 G.M.T. 
w = 153 25 46 
= 749) 956) 10 
ZUG OMS 4 eae 
log g = 9°60424. 
Ephemeris for 12h. G.M.T. (Perrine). 
1902 True a. True 6. log. a. Bright- 
h. m. s, fy ness. 
Oct, 5°5 .-. 20 55 4 +50 28 9566 ... 27°1 
22 Sheed LAS) 15 + 353 O:S12\0) ee ntOcn 
Nov.) (S*5i5 -. DONS 23) -II Oo 07040 ... 13:9 
23 Rie elon gy S -18 13 OST ZOM Aeelree) 
The brightness given for each day is the value obtained on 
comparison with the brightness at the time of discovery, calling 
the latter unity. Perrine adds that, when discovered, the comet 
had a magnitude of 9, with a well-defined, but not stellar, 
nucleus of magnitude 10°5 or 11'0; the diameter of the coma 
was 4’ to 5’, whilst the short, brushy tail could be traced to the 
south-west fora distance of 8’ to 10’. Asa correction to the tele- 
gram dispatched to the various observatories on September 2, 
he mentions that the calculated time of perihelion passage is 
November 23°47, and not November 24°47 as was stated in 
that telegram. 
The above elements and ephemeris agree fairly closely with 
those calculated by Uerr Elis Stromgren, of Kiel, from 
observations made at Lick (September 1°05), Urania (September 
2°58) and Copenhagen (September 4°61), and he has calculated 
an ephemeris for every day from September 6 to October 16. | 
Part of this ephemeris is given below, and from it has been 
prepared the accompanying chart, which shows the comet’s 
approximate daily positions with regard to the neighbouring 
stars. 
FEiphemeris for 12h, M.T. (Berlin). (Stromgren.) 
1902. @. app. 6 app Brightness.1 
hy smh ys? Peder’ 
Oct. 2 22 28 46 +56 15°9 
3 21 55 30 -.. 54 50°5 
4 BIA2ZN23) ie. 2 58°3 5 26'0 
5 20 53 30 50 2571 
6 26 46 47 22°8 
7 20753105, 43 59°4 
8 19 42 28 40 23°5 29°4 
9 24 41 36 42°9 
10 £9) 19.20 33. 435 
II 18 56 4 29 32°9 
12 44 33 26 11°5 26°6 
13 34 31 23 23 
14 25 42 20 672 
15 17 54 17 23°3 
16 18 10 58 14 53°3 21°8 
1 Brightness at time of discovery = x. 
NO. 1718, VOL. 66] 
NATURE 
[OcToBER 2, 1902 
| Archipelagoes : 
MM. Borelly and Fabry, of the Marseilles Observatory, have 
observed the comet on several occasions since its discovery by 
the former, and they report that it is fairly brilliant, has an 
elongated nucleus and a tail 10’ to 12’ long. On September 2, 
at 14h. (Marseilles M.T.), the nucleus appeared to become 
double and thus form two small, globular nuclei ; on September 3 
it had much the same aspect, but on September 5 the nucleus 
was more diffuse and the light of the comet appeared to sensibly 
diminish. 
It may be seen from the above ephemerides that the comet 
will attain its maximum brightness about October 8 and that it 
~ 
~. 
: “ yyra 49% ae 
CEPheus * } cYoNUe Sg Fay * -. . 
1a : Seeee a e P . 10 e 
forgot: mE ¥t.0 ~ : 0 
Oo Ei raee = Wt Bo IF 16 
; ; eae 32 5 in i0 z 
eet? y ane .roe ao . Nea * dE 
of ae #39 Sp at os un HP 
“a . of 
LACERTA * AQUILAS 
Fic. 1. 
passed its maximum declination on September 30, so that by 
November 30 it will be comparatively faint, and so far south 
that it will be a difficult object for observers in the northern 
hemisphere, except on very fine nights and in clear atmospheres ; 
at present (September 27) it is an easy object to find with an 
ordinary opera-glass, and, given good meteorological condi- 
tions, it should soon become obviously visible to the naked eye. 
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