381 35 74 382

Star Occultations observed a t Windsor, N. S. Waleg, in 1898. The thirty six observations during 1898 comprise disappearances only at the moon's dark limb. Nos. I , 4 and

8 were made with a portable 3'/4 inch telescope, Nos. 3 and 23 with the 41/2 inch equatorial, and all the others with the 8 inch equatorial. Transit observations for time were taken on every evening when an occultation was observed.

No.

I

2

3 4 5 6 7 8 9

I 0

I 1

1 2

'3 14 ' 5 16 '7 18

1,

Star

- Lalande 5746

- Lalande I 4963 Lalande 16807 ED. + I 502088

- -

Lalande I 4 3 5 o

Lalande I 6066

BD. + 1501972 43 Leonis

BD. +202385 Lalande 23737

-

BD. +I501973

-

Mag. Windsor M. T.

Jan. ~9~ 8 h 2 ~ m 652 )) 30 8 23 6.7

Febr. 25 7 40 36.6

Mar. 31 6 46 44.0 April I 8 1 2 10.3

>> 2 7 25 9.0 * 24 6 8 40.4 2 2 7 6 39 6.2 > 2 7 6 41 28.6

> 28 6 38 19.1 2 29 8 38 17.4

May 28 9 26 8.1 v 28 9 29 29.9 n 29 6 45 2 .1

B 31 6 48 21.9

= 2 7 8 '9 53.4

2 2 7 6 4 3 '5.9

2 29 8 5 0 39.4

- No.

' 9 2 0

2 1

2 2

23 24 2 5 26 2 7 28 29 30 3 ' 32 33 34 35 36

R e in a r k s. 20, 2 1 , 2 2 , 25, 26, 2 7 ,

28, 30, 3 2 , 34, 36. Disappearances instantaneous and ob- servations good. - 2, 5, 6, 9, 16, 18, 24, 3 1 . Disappear- ances not quite instantaneous and observations good. - 23. Disappearance instantaneous and observation pretty good. - 29, 33. Disappearances instantaneous. - 14. Disappear-

Observations respectively about 160O, I zoo, 80° and 1 4 0 O ance very slow. - 4. Observation good. - 1, 3, 41 8.

Star

Lamont I 196 Lalande 2 5 5 5 6 Lalande 28744 Lalande 30625 Lalande 3 5 5 30 Lalande 2 5 206

Lalande 7 1 2

Lalande 739 Lalande 45894

36 Piscium c Arietis I 7 Tauri 23 Tauri 7 Tauri 28 Tauri 2 7 Tauri

B. A.C. 5023

d +7O33'

- Mag.

8 6 'I,

7 7 7 8 6 7

6 ' 1 2

7 7 6

5 5

3 '12

6 4

6 'I*

Windsor M. T.

May 3 rd 7h34m~zS3

2 28 6 28 2 0 . 2

> 31 6 a 6 48.4 Aug. 2 2 7 6 I 1.6 Sept. 2 0 6 5 1 41.1 Oct. 2 7 8 I I 15.6

July 26 8 1 7 49.3

9 29 6 43 45.6

2 7 8 44 56.5 NOV. 2 2 7 39 29.5

)) 23 7 41 5 2 . 1

n 23 8 1 6 48.3 )) 2 5 8 24 37.4 a 2 7 9 46 12.1 > 27 '0 5 5 53.0 > 2 7 1 1 35 57.4 2 2 7 1 2 5 ' 57.4

2 7 ' 3 4 44.7

from N end of terminator. - 7, I I , 2 7 , 29, 33. Time uncertain to half a second. - 8, 35. Time uncertain to a second. - 8. Observation in strong twilight. - 9. 13S5 W and 6' S of 10. - 1 1 . 3So E an8 2' N of 10. - 16. 3T6 E and 5' S of 15. - 1 7 . Disappearance 90" from N. - 2 0 . Star blurred. - 29. Probably Lalande 2 0 7 . - 35, 36. In contact with terminator.

Observatory, Peninsula, Windsor, N. S. Wales, 1899 Febr. 2 2 . Yohn Tebbutt.

Right- Ascensions, Declinations and proper motions of several stars. By C J. Merfipld.

During the year 1898 the star 7 Virginis was used, by Mr. J. Tebbutt of Windsor F. R. A. S. Lond., as a com. parison star while observing the planet Jupiter, and a1

Scorpii for a similar purpose when observing Uranus. The same observer is now employing the star 114 Tauri for measures of Neptune.

The importance of these observations, and the ne- cessity for good values of the coordinates of the comparison stars, demanded a definitive discussion of the available data ; the results of these researches are appended.

In the deduction, the methods of Dr. H. S. Davis

The year 1875 has been selected as the epoch of reduction. For this purpose the formulae of Professor Hill and the constants of Peters and Struve have been adopted.

Systematic corrections have been applied and the results are referred to the Fundamental- Catalog fur die Zonen - Beobachtungen der Astronomischen Gesellschaft ; the values of these quantities have been interpolated from the tables of Professor Auwers, published in the A. N. 3195-96 and 3413-14.

The data of each catalogue give an equation of con- dition in the form

VF (a, - [B + &o (t - 7-11 = R) ; have been followed; a rCsume of which has been given by the writer, and published in the Monthly Notices of the Royal Astronomical Society London. The following remarks a similar equation for the declination is obtained by re- will however be compatible with this note. placing a, by d, and accenting B , Ap0 and R. The

383

notation of this equation, also the method of reduction will be found in the resume mentioned.

35 74

?'T = v '1875' + [(T - TO) rp I2

accenting Y in the case of d .

384

o Tauri I 14 virgini is 15 cu' Scorpii 9 cuzScorpii 1 0

1855.42 99 25 1865.15 1161 44 1856.28 80 1 8 1859.23 1x8 2 2

The probable errors of the results have been obtained from the squares of the residuals in the usual manner. The probable errors of a and d for any epoch T may be found from the following

+3?5997 +3.0723 +3.5007 i-3.5059

Name I To I Obs. ICat.

+oToo67 +osooor +oToo6 ~ o T o o o 2 2 + 0 . 0 0 2 7 -0.0056 &o.oor fo.00003 +o.o145 -0.0009 &0.007 -)-0.00020

+0.0146 t 0 . 0 0 2 6 fo .004 ~ 0 . 0 0 0 1 4

Name I To 1Obs.ICat.

o Tauri 114 1862.06 7 1 23 ri Virginis 15 1865.62 731 41 wlScorpii 9 1857.60 76 18 co2Scorpii 1 0 1859.09 108 2 1

The writer desires to acknowledge the kindness shown to him by Mr. H. C. Russell C. M. G., for granting per- mission to consult the star catalogues of the Sydney Obser- vatory, and for the courtesy uniformly extented to him.

'1875 I L ' I 4 N

+zio49'4o9247 + 3:'4713 -0!'5185 -0!0482 + o I 40.684 -20.0194 t 0 . 0 3 4 9 +0.1648 -20 19 44.322 -10.0651 +0.4454 +0.1327 - 2 0 31 45.560 -10.0213 t-0.4477 +0.1331

R i g h t - A s c e n s i o n s .

5 h 2 0 m 75687 1 2 13 30.662

16 o 4.618 ' 5 59 29.851

To = Date of observation; p = proper motion; Y~~~~ - - probable error of yP = probable error of p at the epoch To.

P'

-0:'o 1 0 5

-0.0 13 I -0.0380 -0.0529

Y'~875

&0!'036 t o . 0 1 3 t o . 0 6 3 t o . 0 7 4

Sydney, 1899 March 6. C. J. MerjeZd.

Ueber Aenderungen in der Helligkeit des Cometen 1899 a (Swift).

Y'P

&o!oo 14 &0.0006 * 0 . 0 0 2 0

- +0.0026

Am 5. Juni ging folgendes Telegramm aus Dorpat bei

B Juni 4 bedeutende Helligkeitszunahme des Cometen der Centralstelle ein :

Swift. PokrowskLa.

Auf eine an mehrere Sternwarten gerichtete Bitte, diese Beobachtung bestatigen zu wollen, sind die folgenden weiteren Mittheilungen eingegangen.

Telegramm von Dr. Hnrtwzg d. d. Juni 6 : 2 Juni 5 Helligkeitszunahme unzweifelhaft. Kern 91/a Gr.

Gesammthelligkeit 5. Gr. Durchmesser der Coma I 2'. a

Telegramm von Dr. Sckorr d. d. Juni 6 : > Juni 5 stark excentrischer fixsternartiger Kern 6.5 Gr.

Gesarnmthelligkeit des Cometen 5. Gr. Coma 9' Durchmesser.~ Mittheilung von Dr. Holetsckek d. d . Juni 5 : ))In den letzten Tagen habe ich die folgenden, die Re-

obachtung des H. Pokrowski bestatigenden Werthe gefunden. M. Z. Wien Kern (Refract.) Gesammthelligkeit

Juni 1 I O ~ / ~ " 9.10'" 5m4 2 > 9.10 5.7 3 )) - 6.0 4 a 7.8 5.3 a

Kiel, 1899 Juni 7. H. l ireutz.

Neuer Planet 1899 EN. Planet Witt 7. Juni. Position: Juni 8 x z h 16910 M. 2. Urania RA. = ~ 7 2 ~ 5 9 ' PD. = 95'0' tagl. Bew. - 1 2 ' +4' Gr. 9.3. Witt.

I n h a l t zu Nr. 3573-74. A. Anfoniuzai. Osservazioni di pianeti e della cometa Wolf 1898 IV. 353. - W. ViZZiger. Beobachtungen des Cometen 1899 a (Swift). 373. - R. C. AitRcn. Measures of the Satellite of Neptune. 373. - L. Schulhoj. Elements et CphC- meride de la comPte Tempel, 1899 c (1873 11). 375. - A. Stichtenofh. Ephemeride des Cometen 1899 a (Swift). 379. - 7. Tebbutt. Star Occultations observed at Windsor, N. S. Wales, in 1898. 381. - C. 7. MerjeZd. Right-Ascensions, Declinations and proper motions of several stars. 381. - H. Kyeutz. Ueber Aenderungen in der Helligkeit des Cometen 1899 a (Swift). 383. - Wiff. Neuer Planet 1899 EN. 383.

Beschlossen r899 Juni 9. Herausgeber: H. K r e u t a . Druck von C. Schaidt . Expedition: Kid, Nieinannswep 103.