As t r onornische Nachrich t en,

I have the honour to communicate herewith an i n k - resting letter from Professor C. H. F. Peters, Director ~if ' the Litchfield Observatory, relating to the Observations of a star observed at the Naval Observatory in October, 1850, by the late Mr. James Ferguson, and which was iupposed by some astronomers to bc a. trans-Xeptunian planet.

The explanation given by Professor Peters is entirely -atisfactory This explanation is put beyond doubt by the iact that Professor Hall finds, on examining the original observing - books, that Mr, Perguson actually

.Expedition aul' der Kijniglichen - Sternwarte bei Kid. W e r a u s g e b e r : Protl: L)r. C. A. F. Peters,

observed the diflerence of declination correctly on every occasion, except on that of the two transits of Oct. 16 and the first transit of Oct. 19. - A t these transits, the wire was recorded 1, but a t all the other transits, on Oct. 19 as well as on Oct. 2L and Oct. 22, the wire was recorded 2. For some unknown reason, Mr. Fer- guson in his reductions changed all his correct obser- vations to correspond with the erroneous ones.

18iS. Dcc. G . .Jolm Iiodgers, Rear-Admiral, Superintendent.

On the 3rd of September 1851, the Superintendent 11f the Naval Observatory reported to the Hon. secretary l j f ' the Navy, t h a t a star which in October ].Y5(1 ]lad heen repeatedly observed, was no longer found in its place, and therefore probably was an unknown planet I (:odd's Ast. Journ. Vol. 2, p. 53). Mr. Hind of London I ib. page 78) inferred from the positions given, that it could not have been a member of the planetoid group, but rather a planet with a distance of 137, hence beyond Septune, and upon this supposition a search atter it was instituted at the Washington Observatory ,,commencing ~ J I I August 29 and terminating December I I , 1851, d e n d i n g down to all stars of the 11th magnitude, between IY120nl and IShYG" AR, and -- lYo to - 2 i0PO' Uecl:' - (1. cit. page 91). The search was fruitless, and there the matter rested, until quite recently an

it up again; reasoning from the mentioned observations in favor an of exterior planet, using almost the identical, but very uncertain arguments of Xr. Rind of 1h years ago. In order, now, that nobody thereby might be induced to spend months and years upon a renewed search, I hasten to bring to your knowledge the errors I have detected in the ,,Washington Observations for 11160'' (on pages 320 & 321), and which alone have given rise to the misconception. - This pseudo-planet indeed is nothing but a star observed already by Lalande, occurring besides three times in Argelander's Zones and twice in Lamont's, - as I am now going to show.

I will first put together the places of the stars that will come into consideration, denoting them for simplicity of reference with letters.

Mean AR. 1850.0 1 911 131~47 848

17.40.96 19. 2.99 ?L. 39.24

19 23 1.3.82

Mean Dec. 18.50.0 jj' 5"7 52 50 t i 6 0 . 7,:) 43.47, H

-2cJ.42.45.1

I A u t h o r i t y Oe.-Arg. iY444--6, Lam. 886, Gr .12~. Cat. 1519, Yarnall 8268. LL. 36613, Oe.-Arg. 19335-7, Lam. 903. Washington Equ. Obs. 1352 pag. 448, and 1861 pag 391. Tarnal1 S343. LL. 36878, Oe.-hrg. 19669, Lam. 930, Yarnall 8350.

8

115 2240 116

The movablo platc of the micrometer, that served for measuring the differences in declination, carried 3 wires, denotad by 1 , 2, 3 (Wash. Obs. .1850 Introd. page XXX). The object in question, marked (* k), was compared on Oct. 16 twice with the star (a), on Oct. 19, 5 times with (c), on Oct. 21, 3 times with the planet H y g e a , on Oct. 22 once with star (e). Now it

happens that for all the 1 1 instances when (* k) was the object of pointing, the wire ww written wrongly as Nr. 1. while it was in fact Nr. 2. Making this correction, 2 instead of 1 under tlie heading ,,Mic. w." in column 7 wherever (* k) occurs on pp. 320 - 3.21 of ,,Obs. 185OU, the 9th column, with regard to the wire distances given in the Introduction, will stand thus:

Oct. 16 for +39'"'.217 read + 9r".053 ,, 39.017 ,, 8.851

Oct. 19 for +58rp''451 read +28rer*283 Oct.21 for --19rer*8G9 read -t101v'-i9S ,, 58.513 ,, 28.345 19.405 ,, 10.567 ,, 58.615 ,, 28.427 ,, 19.267 ,, 10.91)O ,, 68.600 ,, 28.432

, ,, 58.722 ,, 28.554 Oct. 22 for - 9.207 read -39.3i4

and the star therefore is identical with (ci) or Yarnall 8343.

After having recognized the star (* Ic) as LL. 36613, it remains yet to show that on Oct. 21 it was really

for this planet only the approximate ephemeris in the Berlin Jahrbuch for 3862, giving the places only to

the planet H y g e a that was observed. I have on hand

tenths of minutes. Correcting this ephemeris by the Washington Observations of H y g e a of preceding and following days, the planet's place is found therefrom for Oct. 21, 5500 Berlin m. t. (the time of observation) :

The reduction of the observation, assuming the a = 19h21m3 d = - 20°49' 9.

Corr. Chron. to be + 31816, stands thus: