Burnham: Measures of Proper Motion Stars 
This has been given from transit observations: 
Stumpe o".20$ in io7?6 
Porter 0.200 in 116.7 
Auwers 0.204 in 108.2 
Boss 0.213 in 119.5 
As a further check on the corrected value, a nearer star 13 m 
is connected: 
1911.625 
121?10 
97-24 
.644 
121.16 
97.04 
.663 
121.46 
97-13 
1911.64 
121.24 
97.14 
Anonymous 
R. A. 2 h 45 m 
54 s Decl. + 
22° 37'8' 
M. Puiseux, of the Paris Observatory, has called attention to 
a 10.4 m star apparently having a large proper motion {Bull. 
Ast., xxvi, 416). This was noted on a photographic plate made 
November 25, 1908. Comparing this with a previous plate, he 
found for the proper motion of the small star: 
o"7o8 in 241?7 
cordant when compared with the other two, and’ must there¬ 
fore be rejected if use is made of the others. From the mean 
of AB and AC we have for the proper motion of A: 
0^678 in 261 °2 
The smaller apparent change in AD may be due to errors of 
observation in all the measures, or to a possible proper motion 
in that star, although this is to the last degree improbable. To 
settle this question hereafter, I have connected this star with 
others shown on the print: 
1910.701 
D and E (10.0) 
289 ?75 
ioi'fio 
•703 
289.78 
101.25 
.739 
289.97 
100.58 
.742 
290.01 
100.51 
1910.760 
E and F (12.5) 
2 I 9 ? 6 o 
i 57"93 
.780 
219.51 
158.21 
.818 
219.30 
158.09 
1910.818 
E and G (12.5) 
25o?58 
2 i 5"76 
.838 
250.48 
215-65 
He gives the place (1900) as above. 
The photographic print shows three stars, the nearest two 
exceedingly faint, and very much fainter than the smallest stars 
usually visible on the 
astrographic plates. My measures of 
these stars 
are: 
A and B (11.1...13.2 
) 
1910.5S9 
i75°68 
96*73 
.605 
176.26 
96.93 
.666 
176.23 
95-84 
.678 
176.37 
97-38 
A and C (13.3) 
1910.589 
113-82 
101+7 
.605 
II 3 - 4 I 
101.78 
.666 
113-03 
IOI.78 
.678 
H 3-73 
101.12 
A and D (12.1) 
1910.091 
301+0 
162''09 
• 570 
301.03 
162.09 
.586 
301.05 
l6l.8S 
• 589 
301.00 
161.85 
M. Puiseux gives the photographic relative positions of these 
stars: 
AB 
1908.90 
176+0 96"37 
Photo. 
1910.63 
176.13 96.72 
411 (3 
AC 
1908.90 
114.20 100.34 
Photo. 
1910.63 
113.50 101.44 
411 (3 
AD 
1908.90 
301.10 161.69 
Photo. 
1910.46 
301.03 161.97 
411 p 
From these positions 
we have for the apparent motion of A: 
AB R. 
A. — o" 4 68 Deck + o'/185 
AC 
— 0.873 
— 0-393 
AD 
+ 0.218 
+ 0.013 
When the errors probable in the photographic and the micro- 
metrical results are considered, it is obvious that no high degree 
of accuracy for the proper motion, if any exists, could be ex¬ 
pected from positions having a time interval of only a little 
more than one and a half years. The most distant star is dis- 
Professor Frederick Slocum has kindly measured the print 
referred to, with all possible accuracy, for the positions of these 
stars. The comparisons are as 
follows: 
DE 1908.90 
290?73 
101+9 
Photo. 
1910.72 
289.88 
100.86 
411 
P 
EF 1908.90 
219.71 
158.27 
Photo. 
1910.78 
219.47 
158.08 
3 o 
P 
EG 1908.90 
250.55 
215-52 
Photo. 
1910.83 
250.53 
215.70 
211 
P 
From these measures it would seem probable that D has some 
proper motion, since there is no evidence of change in EF or 
EG. The two positions of DE imply a movement of D of o"87 
in 355 ° 6 . 
It would appear that, for all practical purposes, measures 
from a print can be safely used in lieu of those from the original 
plate. The print-measures of the other two stars are: 
AB 1908.90 i76?2 96^63 
AC 1908.90 114.0 100.27 
A careful re-measurement of these stars with the micrometer 
a few years hence will give a substantially correct value of the 
movement of both stars, if the apparent change is real. 
Lalande 5273 (5.8...13.3) 
R. A. 2 h 46™ 27 s Deck + 6i° 2' 
A and B 
1911.625 
.644 
•755 
255-27 
256.10 
256.17 
50"75 
50.63 
50.95 
1911.67 
255+5 
50.78 
A and C (11.3) 
1911.625 
43+7 
9 i "37 
.644 
43-23 
9 t- 5 i 
• 755 
43-40 
91.60 
1911.67 
43-30 
91.49 
11 
