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Royal Greenwich Observatory.

Five-year catalogue of 258 fundamental stars, deduced from observations extending from 1887 to 1891, made at the Royal observatory, Greenwich online

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C 5 775



FIVE-YEAR CATALOGUE



OF



258 FUNDAMENTAL STARS



DEDUCED FROM



OBSERVATIONS

EXTENDING FROM 1887 TO 1891,



MADE AT THE



ROYAL OBSERVATORY, GREENWICH,

UNDER THE DIRECTION OF

WILLIAM HENRY MAHONEY CHRISTIE, M.A., F.R.S.,

ASTRONOMER ROYAL,

REDUCED TO THE EPOCH

1890-0.

(Forming Appendix to the Greenwich Observations for the Year 1891.)




L N D N :

PRINTED FOR HER MAJESTY'S STATIONERY OFFICE,
BY DARLING & SON, ITD., 1,2,3, & 5, GREAT ST. THOMAS APOSIT.E, E.G.

1893.



INTRODUCTION

TO THE



GBEENWICH FIVE-YEAR CATALOGUE



OF



258 FUNDAMENTAL STARS, .

DEDUCED B^ROM OBSERVATIONS EXTENDING FROM 1887 TO 1891,
AND REDUCED TO THE EPOCH

1890-0.




This Catalogue has been formed to supply revised places of Fundamental Stars,
available for determination of instrumental and clock errors, and for use in the
Nautical Almanac, in the interval between two' successive Greenwich General Catalogues,
which it is proposed to form at intervals of ten years, so that a sufficient number of
observations of each star may be accumulated. In the case of the Fundamental Stars,
however, there are usually a sufficient number of observations in the course of five
years to give trustworthy positions, and it has, therefore, been thought advisable, in
view of possible uncertainty of proper motion when applied for more than ten years, to
publish the present provisional Catalogue of Fundamental Stars based on the five
years' observations 1887-1891, strengthened, where necessary, by combining with
them the places of the Ten- Year Catalogue (188OO).

The stars whose places are given in this Catalogue are

1. Those contained in the Greenwich Clock Star Lists.

2. Circumpolar stars whose Ephemerides are published in the " Connaissance des
Temps," or in the " Ephemerides des Etoiles de Culmination Lunaire et de Longitude,
par M. M. Loewy."

3. Stars in the Nautical Almanac, but not in the Greenwich Clock Star Lists.
The following is the process of formation of the star places in this Catalogue.

2990
SO 114268008/93 Wt , D & S. GREENWICH FIVE-YEAR CATALOGUE POH 1890. a 2



4 GREENWICH FIVE-YEAR CATALOGUE OF FUNDAMENTAL STARS FOR 1890.

I. FORMATION OF RIGHT ASCENSIONS.

The determinations of Right Ascension of each star, which are to be combined in
order to form the Right Ascensions in this Catalogue, are those given in the Annual
Catalogues printed in the successive volumes of Greenwich Observations from 1887
to 1891.

The Right Ascensions of each Annual Catalogue depend essentially upon the Right
Ascensions assumed for the stars whose transits are employed in each year to ascertain
the errors of the Transit-Clock ; it is necessary, therefore, in the first instance to
ascertain the amount of correction required for the assumed Right Ascensions of the
Clock Stars. Now it appears from the discussions of the Observations for the Position
of the Ecliptic in the Greenwich Observations 1887-1891, that the Right Ascensions
of the Clock Stars used in those years require the following corrections :

8.

1887 ... 0-059.

1888 ... +0-072.

1889 ... + 0*024.
... + 0-092.
... +0-088.



The mean of these is + 9 -043 ; but it was considered advisable to wait for further
information before making such a large correction to the Right Ascensions, and no
correction for Epoch has therefore been applied to the Right Ascensions taken from the
Greenwich Observations 1887 to 1891. The present Catalogue is thus referred to the
Epoch of the Standard Right Ascensions of the Ten- Year Catalogue (1880'0) ; and
also of the Nine- Year Catalogue (1872'0) ; for it is shown on page 9 of the
Introduction to the former, that the mean difference between the two sets of Standard
Right Ascensions is only 9 '0001, which is practically insensible. It should be
remarked that the Mean R.A.'s of Clock Stars used during 1887 and 1888 were taken
from the Standard R.A.'s of the Nine- Year Catalogue ; during 1889, 1890, and 1891,
from those of the Ten- Year Catalogue.

The results for the separate years as given in the Annual Catalogues were reduced
to 1890*0 by using the elements given in the Ten- Year Catalogue, where Struve's
Constant of Precession, and Prof. Auwers' Proper Motions are used. In the case of
Sirius and Procyon, corrections for orbital motion deduced from Prof. Auwers' Papers
(Publ. Astr. Gesellschaft, No. VII., and Astr. Nachr., Nos. 1H73 and 3085) have
been applied to the separate years in forming the Mean R.A. 1890'0.



\



INTRODUCTION. 5

A separate determination of the Right Ascensions of Clock Stars was made in
which only those observations were included where the group of Clock Stars
extended over 12 hours at least, in a similar manner precisely to that described in the
Introductions to the Nine- Year and Ten- Year Catalogues, though the number of such
groups is, of course, not so large. The excess of R. A. from the 12-hour groups above
that of the Five- Year Catalogue was tabulated for each star and the mean formed for

each hour of R.A. by combining the individual excesses with weights = , where

m+w

m and n are the munbers of observations in the Twelve-Hour Groups, and in
the Catalogue respectively. Similarly the corrections to the R.A.'s of the Five- Year
Catalogue, as depending on the N.P.D. of the star, were formed for each 10 of N.P.D.
Both sets of corrections are given in the following tables, the Resultant Corrections
applicable to the R.A.'s of the Five- Year Catalogue being the algebraic sums of the
two. The mean of all the corrections is less than s -0005, and though it enters into
both sets, no sensible error is thus introduced by adding the two sets together.

MEAN CORRECTIONS TO EIGHT ASCENSIONS OF FIVE - YEAR CATALOGUE,
DERIVED FROM A COMPARISON WITH R.A.'s OF 204 CLOCK STARS FROM
iz-HOUR GROUPS.



Limits
of


Correction.


i


Limits
of


Correction.



m


Limits
of


Correction.


4


Limits
of


Correc-


a


B.A.




a


B.A.




8


B.A.




9


N.P.D.




i


h li
O-I


8 8


4 8


h h

89


8 8


23


h h
16-17


+ 'OO5 '007


30




50 60


8

'OO2


67


1-2


-oo7-f-*oo5


56


9-10


-009'0o8


20


I7-I8


-005'O05


44


60 70


+ 'O02


176


2-3


"OO2 ~(~*OOs


45


IO-I I


009 'OO7


26


18-19


OOlHt'OO4


63


70 80


ooo


192


3-4


*oo c -t- '006


33


I I-I2


+ '01 2 '009


16


19-20


+ 'OO2 + 'C04


68


80 90


003


221




*OO I ~f~ *OO C


47


12-13


+ - oo 5 -008


20


20-21


+ 'oi4 - oo6


37


90-100


ooi


146


5-6


+ *oio'oo6


32


13-14


004 '005


46


2 1-22


-oio - oo6


36


IOO-I 10


'OOI


80


6-7


+ *oio'oo6


35


14-15


*oo 5 ~^~ *ooo


37


22-23


000+ -005


53


1 10-124


+ 006


35


7-8


-oii-oo6


39


I5-l6


-|- *OO2 ~f~ *OC'6


32


23-24


+ -002 -006


3i









The probable errors appended with the sign have been computed by taking the
probable error of a single determination of R.A. as O s '034.

It appears that the errors of the assumed places of the Clock Stars, originally derived
from Pond's Catalogue, have been greatly diminished and are now very small.



II.- FORMATION OF MEAN NORTH POLAR DISTANCES.

The determinations of N.P.D. of each star, which are to be combined in order to form
the N.P.D. in this Catalogue, are those given in the Annual Catalogues printed in the
successive volumes of Greenwich Observations, 1887 to 1891, to which the sam



6 GREENWICH FIVE-YEAR CATALOGUE OF FUNDAMENTAL STARS FOR 1890.

statements apply generally as have been made for K.A., omitting all that relates to
Correction for Equinox. The adopted colatitude is 38 31' 21"'90 throughout. The
corrections required for orbital motion, in the case of Sirius and Procyon, have been
deduced from Prof. Auwers' papers referred to before.



III. EXPLANATION OF THE SEPARATE COLUMNS OF THE PRINTED CATALOGUE.

The " No." is the ordinal number of this Catalogue, the stars being arranged in order
of R.A. 1890-0.

The " Star's Name " is taken from one of the following authorities, the order of
preference being the order of mention of the authority below :

1. Flamsteed's Constellation No. and Constellation, with Bayer's Letter, taken from

Baily's Edition of Flamsteed, or the British Association Catalogue.

2. The No. in Bessel's Fundamcnta Astronomice deduced from Bradley's Observations,

referred to as " Bradley."

3. The Hour and No. in Piazzi's Catalogue, Edition 1814.

4. The No. in Groombridge's Catalogue.

For Circumpolar Stars the result of observations below the pole is shown separately.

The " Magnitude " is taken from the Harvard Photometry for stars contained in that
work, and for other stars (marked *) from the Bonn Durchmusterung. The magnitude
in the Uranometria Nova Oxoniensis is given in the Notes for all cases in which it
differs by more than 0'2 magnitude from that in the Harvard Photometry. The
magnitudes of the components of double stars, taken from Struve's Mensurcn Micrometricce
or other authority, are given in the Notes. In the case of Variable Stars, the limits of
magnitude and the period given' in the Notes are taken from Mr. Chandler's Catalogue
in the Astronomical Journal, Nos. 179, 180.

The next six columns consist of three pairs, the first of each pair referring to the
observations in 1887-1891, immediately under discussion, and the second to the
Ten- Year Catalogue.

The first pair gives the "Mean Date " expressed in years and decimals of a year
reckoned from 1800.



INTRODUCTION. 7

The .second pair (columns 6 and 7) gives the "Number of Observations," being the
aggregate of all the observations in the different years, above and below the Pole
respectively, in column 6, and the aggregate of all observations in column 7.

The third pair (columns 8 and 9) gives the seconds of Mean R.A. formed in the
manner already described.

In forming the adopted Mean R.A. 1890'0 the following rules have been observed :

(1.) In all cases where the total number of observations in the years 1887-1891
is ten or more, the mean of these observations is the adopted Mean R.A., equal weight
being assigned to observations above and below the Pole.

(2.) When there are five to nine observations in the period 1887-1891, the adopted
Mean R.A. is formed by combining these with the result brought up from the
Ten-Year Catalogue, giving weight to each observation in the latter.

(3.) When there are less than five observations in the period 1887-1891, weight ^ is
given to each observation in the Ten- Year Catalogue in combining the two means.

Assuming that there are on the average twice as many observations of a star in the
Ten- Year Catalogue as in the Five- Year Catalogue, this is equivalent to giving the
Ten- Year Catalogue weight ^ on the average when there are from five to nine observa-
tions in the Five- Year Catalogue, and to taking the simple mean between the Five- Year
and Ten- Year (on the average) when there are less than five observations in the
former. If we assume that the probable error of one observation of R.A. is 8 -034,
and that the Ten- Year Catalogue deduced place for 1890'0 is affected by a probable
error of proper motion, or other systematic error represented by a, and express the
condition that the result of seven observations in the Five- Year Catalogue should have
double the weight of 14 observations in the Ten -Year Catalogue ; then x = 8 -016 ;
or the method of combination adopted is equivalent to assuming that the results of
the Ten- Year Catalogue reduced to 1890'0 are affected by a probable error of proper
motion or other systematic error amounting to S '016.

*

The " Annual Precession 1890'0 " for stars beyond 5 from the Pole has been
formed by applying to the Precession in the Ten- Year Catalogue the proportional
part of the " Secular Variation 188OO " to reduce it to 189OO.

The " Secular Variation 189OO " is the same as that given in the Ten- Year Catalogue,
except for stars within 5 of the Pole. For these latter stars both the Annual



8 GREENWICH FIVE-YEAR CATALOGUE OF FUNDAMENTAL STARS FOR 1890.

Precession and the Secular Variation have been computed by the help of Folie's
" Douze Tables pour le calcul des reductions stellaires," in which Struve's Constant
of Precession is used. The Precession is given by the formula



+ i s- 3369 [log. = 0-12611] sin R.A. cot. N.P.D.
and the Secular Variation by the formula

A + B cot. N.P.D. + C cot. 2 N.P.D.
where

A = o s -ooi9o + o'-oo65o sin 2 R.A.

B = o s- ooo57 sin R.A. + o"-o2987 cos. R.A.

C = + o"-oi3oo sin 2 R.A.

The second term of the precession is readily computed from these tables, and the
quantities A, B, C, are therein tabulated for every minute of R.A. These formulae
correspond essentially with those used in previous Catalogues, but the method of
computation is simpler.

The " Annual Proper Motion 1890'0 " has been taken from Prof. Auwers' " Neue
Reduction der Bradleyschen Beobachtungen," or his " Catalog der Fundamental
Sterne," for stars contained in either of those works. The authority for other Proper
Motions is given in the Notes.

To the columns relating to N.P.D. the same remarks generally apply as in the case
of R.A., except that in combining observations above and below Pole the weights
mentioned below were used in forming the means. For stars whose N.P.D does not
exceed 15 the observations above and below Pole are considered equally good ; from
N.P.D. 15 to N.P.D. 36, those below Pole have the weight f for each observation ;
from N.P.D. 36 to N.P.D. 41 those below Pole have the weight : beyond 41
N.P.D. the observations below Pole are not used, and in the case of those stars
observed below Pole only the mean result is enclosed within brackets.

i

The Annual Precession and Secular Variation for stars not within 5 of the Pole
have been formed as explained above ; for the stars within 5 of the Pole they have



INTRODUCTION. 9

been computed by the help of Folie's Tables referred to above. The Precession is
given by the formula

2o" - o53O cos R.A.
which is taken directly from the Tables, and the Secular Variation by the formula

A 1 + B 1 cot. N.P.D.
where

A 1 = + o"-oo86 cos R.A. + o'^So sin R.A.
B 1 = + o"-i95o sin 8 R.A.

The quantities A 1 and B 1 are given directly in the Tables for every minute of R.A.



IV. COMPARISON OF THE PLACES OF CLOCK-STARS IN R.A. AND N.P.D. FROM
OBSERVATIONS MADE IN THE YEARS 1887-1891 WITH THOSE OF THE TEN-
YEAR CATALOGUE.

The following tables give the mean excess of R.A. and N.P.D. from the Five-Year
Catalogue over those deduced from the Ten- Year Catalogue, for each hour of R.A.,
and for every 10 of N.P.D. , weights being assigned to the individual excesses

according to the formula , where ? and n are the numbers of observations

m + rv

in the two Catalogues respectively.

EXCESS OF R.A.'S OF CLOCK STARS FROM FIVE-YEAR CATALOGUE ABOVE THOSE
OF THE TEN- YEAR CATALOGUE REDUCED TO 1890-0 FOR EVERY HOUR OF R.A.
AND EVERY 10 OF N.P.D.



Limits
of


Correction.


M

be


Limits
of


Correction.


be


Limits
of


Correction.


3U




Limits
of


Correc-


s

.s


E.A.




'S


B.A.






R.A.




'




N.P.D.


tion.































f


b b


s s




h h a




b h








o o


_




0-1


-f- *oo s -f- '003


'47


8-9


-OI4+-005


55


l6-I7


'OO8 '004


74




50 60


+005


156


1-2


*ooo-f- *oo3


133


9-10


'006+: '004


68


I7-I8


009 '003 j 95




60 70


+ 'OOI


461


2-3


+ '005 '003


1 1 1


10- 1 I


+ '007 -004


87


18-19


-{-003^*003 | IjO




70 80


ooo


525


3-4


'007 ~^~ '003


95


I I-I2


'005 '004


74


19-20


+ -oo6'oo3


157




8090 | -|- - ooi


60 1


4-5


*ooo -f- '004


88


12-13


+ '004+ '004


75


20-21


+ '004+ '003


109




90-100


-005


339


5-6


+ '004 + -004


87


'3-H


+ 001 +-003


117


21-22


*oi o-f- "004


90




IOO I IO


'OO2


227


6 r j


'O02 + -003


99


14-15


+ 008 -004


89


22-23


*oi 6-1- '003


125




1 10-124


'006


8 9


7-8


-f-'ooi '003


107


I5-l6


ooo '004


87


23-24


+ '002 'OO4


79











SO 11426. GREENWICH FIVE- YEAR CATALOGUE FOR 1890.




10 GREENWICH FIVE-YEAR CATALOGUE OF FUNDAMENTAL STARS FOR 1890.



EXCESS OF N.P.D.'s OF 211 CLOCK STARS FROM FIVE-YEAR CATALOGUE ABOVE
THOSE OF THE TEN-YEAR CATALOGUE REDUCED TO 1890-0 FOR EVERY
HOUR OF R.A. AND EVERY 10 OF N.P.D.



Limits






limits






Limits






Limits





of


Correction.


I


of


Correction.


A


of


Correction.


bo


of


Correction. U


B.A.




ffl


E.A.




JD


E.A.




9


N.P.D.




2


h h
I


//
0-09


113


h h

8- 9


it

+0-13


47


h h

16 17


+ o"i3


87


, o
50 60


+ O*I3


137


12


O'OO


90


9 10


0-04


74


17 18


0'22


130


60 70


0-18


407


2-3


-0-14


9 1


10 II


0-09


78


18 19


+ 0'!2


148


70 80


o'og


499


3-4


0-18


76


I I 12


+0-03


93


19 20


O'O7


147


80 90


0-04


53 1


4-5


-0-15


64


12 13


0*05


66


2O 21


OTO


93


90 100


0'02


327


5-6


0-29


65


1314


+ O'I I


96


2122


-0-13


84


100 110


+ 0'OI


205


6-7


-0-15


79


14-15


+0-05


129


22 23


0'20


103


1 10 124


+ 0-13


79


7-8


+ 0-05


81


15-16


O'OO


94


23-24


0*07


57









V.- COMPARISON OF THE PLACES OF CIRCUMPOLAH STARS AS OBSERVED ABOVE AND

BELOW THE POLE FROM OBSERVATIONS MADE IN THE YEARS 1887-1891.

The following tables show the mean, excess of R.A. and of N.P.D. above Pole for
all stars in the Five-Year Catalogue, of which observations were made both above and
below the Pole. The star is designated by its No. taken from the Five- Year
Catalogue. The figures on the same line as the No. refer to the observations above
the Pole, those on the next line to the observations below. The excess of R.A. is
multiplied by sin N.P.D. in all cases, to reduce it to equatorial interval. The weights
assigned to each star are computed as follows : For R.A. if m and n be the number of
observations above and below the Pole respectively, the weight assigned is

. The maximum weight for any star is thus 20, which corresponds to
m + n + -5- mn J

an infinite number of observations above and below the Pole, and the expression is
equivalent to that for N.P.D. for stars at about 30 from the Pole. For N.P.D. the
weights used are determined by use of the " Probable Errors of Greenwich Observa-
tions in Zenith Distance," given by Mr. Stone in the Monthly Notices of the Royal
Astronomical Society for 1869 June 11, page 324. Putting n for the number of observa-
tions of a star above Pole, e for the probable error of one observation ; HI and c\ the
similar quantities for the observations below Pole ; e the probable systematic error
affecting all observations of the same star, and depending on outstanding division error,
Uncertainty in the constant of refraction, &c. ; the formula employed to determine the



INTRODUCTION.



11



weight to be given to that star is



would make e =*0"'16, the weight becomes
for use in this investigation.



2?i "l 2 I,' 1

-, 5 o , or assuming ft -*& e, which

,*>' 4- )^ J -I- A nn <>-' o ~ lw

/t|C i /CGI T^ /t/t-iC n

2 nHj



- + ne* + %



-^ which has been adopted



TABLE OF THE EXCESS OF MEAN K.A. AND MEAN N.P.D. ABOVE POLE, ARRANGED

IN ORDER OF RIGHT ASCENSION.



s ir'<
So,


Moan 11. A.

1 890-0.


Beta

Data.

1800 +


No. of
Ota


ExeC93 Of
11. A.
above Pole
x sin N.P.D.


Wuight.


Mean N.P.D.

i S^o'o.


Mean
D-ite,

1800 -t-


No. of
Obs.


Excess of
N.P D.
above Pole.


Weight.




h in B






,




o / i











7


o. 34. 16-000

15-940


89-3I

89-98


2

3


+ 0-033


4


34- 3-58-28
59-07


89-81
89-98


3

3


- 0-79


5


12


o. 53.48-194

48-153


89-83
90-13


34
38


+ 0-003


16


4. 2O. O'2I
0-42


89-66
90-25


35
34


0'2I


29


16


i. 18. 30-679
30-680


89-25
89-48


230
224


O'OOO


'9


i. 16. 41-30
41-76


8?53


296
33=


0-46


38


22


i. 46. 28-909
28-952


91-36

9''45


3
i


0-019


3


26. 52. 19-50
18-46


91-51

90-77


4
3


+ 1-04 6


37


3. 16. 28-097




2


rvnfiS




40.31. 51-36


91-00


2


' l
*




28-202


88-35


I


<-) \J\JO




51-51


88-35


I




46


4. 2. 13-562
13-233


90-24
90-35


34

47


+ O-027


16


4.44. 8-37
8-86


90-59
90-35


13

47


- 0-49 25


56


5- 8.33-578


91-38


3


0-188


c


44- 6.53-93


91-08


2 + 0-06


2




33-847


88-12


3




J


53'87


88-12


3




76


6. 48. 46-624
46-016


89-84
89-10


25
46


+ 0-031


15


2.46.54-40

54-88


89-38
89-49


88

177


0-48


36


90


7.46.51-175
51-670


90-30

90-48


49
104


0-009


17


i. 2.25-81
26-31


90-13
90-56


36

79


0-50


32


98


8. 51.40-489


88-19


3


_ , o*n i o




4'- 3i- 37'22


88-19


3


1-77


]




40-504


87-64


I


\J \J 1 W




38'99


87-64


i


77




IO2


9- 21. 21-791

21-678


89-92
90-88


'.I


+ 0-016


'3


8. 1 1. 17-96

17-78


89-97
90-90


23

22


+ 0-18


25


117


10. 56. 56-212


89-61
89-80


I


0*0 10


4


27. 39. 19-64
20-16


89-40

89-80


. 8

2


- 0-52


5


122


I 1. 24. 52-078
52-2O8


.88-37 ! i
89-80 3


- 0-045


3


20. 3. 43-30 ,
42-63


89-32
89-80


8
9


+ 0-67


'4


126


I I. 48. 2-568
2 - 6l I


91-30 , 2


0-025


4


35.4I.37-28

37-28


90-31
91-30


5

2


O'OO


4


,3,


12. 14. 22-I57

20-8I5


90*07 48

89-96 i 54 ;


'1.41.24-97 90-09
25-45 89-89


4'
44


- 0-48


3'


151


14. I. 24-658
24-776


88-01
0-050 v
90-69 3


2 5 . 5-53-86


87-78
89-27


'4
9


+ 0-03 15


'59










I 5. 23. 41-61 89-40


'7


0-53 11












42-14 88-93


4


J -J




'164


15. 12. 50-2O3


90-24


'3 i Q-O32 1 6


2.20.41-43 90-17


43


O'l I


28




49'427


90-47 30


4'"54


90-45


22






170


15.47. 59-665
59-942


89-22
88-78


J - 0-057 6


1 1. 52. 2-60
2'33


89-46
89-01


12

7


+ 0-27


'5


'75










28. 14. 12-29


88-36


3


+ 0-51


4












11-78


90-88


2







GREENWICH FIVE-YEAR CATALOGUE OF FUNDAMENTAL STARS FOR 1890.



TABLE OF THE EXCESS OF MEAN R.A. AND MEAN N.P.D., &C. continued.



Star's
No.


Mean E A.
I Sijo'o.


MOOD

Date.
1800 +


No. of
Obs.


Excess of
H.A.
above Pole
x sin N.P.D.


Weight.


MeanN.RD. ^f"

"^ f+


No. of
Obs.


Excess of
K.P.D.
above Pole.


Weight.






j


|




o / "






"






h in s




















182


16. 57. 14-900
15-639


87-94
gi-O}


3 o-ioo

2


4


7.46.57-53
57-06


89-32

89-40


'9

6


.

+ 0-47 1 6


I8 7


17. 27. 56-806
56-708


88-53
87-96


8 ,
+ 0-060


3


37-37- i-39
1-38


88-47
87-96


8
i


+ o-o i


2


195


18. 7- 47'59 8
47-32I


88-98
90-03


59
3


+ 0-015


16


3.23. 17-92
18-41


89-32
89-26


'7 1
61


- '49


34


209


I9-33- 35-3i8
337>5


89-39
89-79


65

18


+ 0-029


15


i. 1.59-02
59-51


89-29
89-27


'45

82


- '49


35


220


20.33.44-984
45-276


90-04
90-1 1


59
'9


0-044


15


8. 56. 24-06
24-18


89-97
90-0^


65

24


0'12 28


230


21. 15.57-172
57-I3I


89-21
88-71


10
8


+ 0-019


9


27. 52.49-00
49-96


89-17
88-83


16

8


0-96 13


232


21. 21. 28-509
28-OI2


89-93
90-18


43

7


+ 0-030


1 1


3.25. 9-19
9'94


89-92 28
90-16 6


- o-75 '7


2 34


21. 27. 14-281

I4-455


88-92
89-82


2

3


- 0-059


4


19. 55. 19-51
19-47


88-77
90-09


6
6


+ 0-04 1 1


243


22. 21. 58-914
58-833


90-21
90-21


56

2 7


+ o'ooS


16


4.26.45-09 ' 8.9-94
45-61 89-78


36
i?


- 0-52 25


253 23.27.49-643

49-3I5


90-23
89-94


56

35


+ 0-019


16


3- i7-57'4 2
57-50


89-92 45
89-75 '< 35


0-08 30


255


23- 34- 49'74

50-078


90-86
87-34


2
I


0-076


2


12. 58. 52-63

5 2 '95


89-42
88-90


9
*$


0-32


19



The weighted means for each 6 h - of R.A. are shown in the following table, the
corresponding numbers for the Ten- Year Catalogue, as found from the table on page 46
of its Introduction, being added for comparison.



Limits of
RA.


Mean Excess of R.A. above


1 3 4

Online LibraryRoyal Greenwich ObservatoryFive-year catalogue of 258 fundamental stars, deduced from observations extending from 1887 to 1891, made at the Royal observatory, Greenwich → online text (page 1 of 4)