Page images
PDF
EPUB

meteors seen was much greater. The increase was especially noticeable as the Moon sank toward the western horizon and was obscured by clouds. The total number of meteors counted on Tuesday night was 198, of which 53 were platted as shown on the accompanying chart. Many are noted as showing trains persisting for a few seconds and seven were thought to follow a slightly curved path. In no case was a meteor seen to explode, to change its course abruptly or to leave a train persisting for more than a few seconds. The chart shows six meteors which were quite certainly not Leonids and as many more are doubtful.

Several photographs were taken Tuesday night by a camera mounted on the equatorial telescope but no meteor trails were shown on the plates.

The total number of meteors counted on Thursday night, Nov. 16, between 15h and 18h 30m was 30. Two of these were not Leonids. Details of the count are given in the following table:

[blocks in formation]

12:30-12:45 0 Hazy. Moon shining. 17:30-17:45 26 Clear.

[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][ocr errors][merged small][ocr errors][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small]

BOSWELL OBSERVATORY, Doane College, Crete, Nebraska.

LEONIDS AT UNIVERSITY PARK, COLORADO.

The following observations of the meteoric shower were made by the writer, except on the night of Nov. 15-16, when they were made by a corps of volunteer observers. Mountain Time was used as the standard:

Nov. 13: 12:30-13:00; no Leonids; clear.

13:30-14:00; no Leonids; clear.

14:30-15:00; one Leonid; clear.

15:30-16:00; eight Leonids; Moon has set: clear. One of the sixth magnitude glanced.

16:30-17:05; four Leonids; one faint one glance 1; clear.

The average brightness was equivalent to that of a star of mag. 3 or 4. Nov. 14: 17:00-17:35; eleven Leonids; hazy, but stars of mag. 5 were visible. Three or four were brighter than mag. 1, and no one was as faint as mag. 5. The average magnitude was 3.

17:35-18:00; four Leonids; low lying haze spread rapidly toward the zenith, and during the last five or ten minutes the stars in the Sickle were barely visible. One meteor, brighter than mag. 1, dashed across the western sky at a Leonid's pace, but its trail, which lasted perhaps two seconds, passed about five degrees above the Sickle, and it was not counted as a Leonid. The sky was cloudy before 17:00; after that there was no Moon.

Nov. 15: see below.

Nov. 16: 13:00-13:15; no Leonids; hazy so that nothing fainter than mag. 3 was visible.

13:30-13:45: no Leonids; some what clearer.

14:00-14:15; no Leonids; only the brightest stars visible. After this it became cloudier and observations were useless.

Nov. 17: 14:15-14:30; no Leonids; observed through a large rift in the clouds. 14:45-15:00; 1 Leonid; an area as large as I could survey was clear.

15:00-16:15; cloudy.

16:15-16:30; no Leonid; large clear area of sky.

16:45-17:00; no Leonid; sky perfectly clear in the vicinity of Leo.

17:15-17:30; no Leonid; sky cloudless.

17:45-18:00; one Leonid; sky cloudless, but light because of approaching dawn.

Nov. 16. The observers were mostly in pairs, one person observing for fifteen minutes while the others rested; the two thus kept a continuous watch upon some part of the sky. Each pair was instructed to face N., or N. E., or E., etc., and to watch a point at an altitude of 45° noting every Leonid seen, and rejecting others. The zenith was also watched by observeis recumbent on a mattress. Professor E. B. T. Spencer was in charge of those counting: he rang a bell at each quarter hour, having given a warning signal two minutes previously. Below is a very condensed summary.

Mary C. Traylor and Grace M. Sater faced north and counted five between 13:00 and 15:00. Clouds then intervened. Between 15:00 and 16:15 Miss Traylor faced east and counted four.

Myron A. Pattison and Guy W. McCreery faced east and counted forty-four between 13:00 and 16:45.

Edward Stauffer and Chas. F. Seitter faced north-east and counted fifteen between 13:00 and 15:15. Clouds then came. Between 16:00 and 16:15 Mr. Stauffer counted one.

Fred Winship and Loyd Winship faced the zenith and counted three between 13:00 and 14:30. From 14:30 to 17:00 the zenith was mostly cloudly but seven were counted.

Fred Stover and Earl K. Terry faced south-east and counted sixty-four between 12:45 and 18:30, none being seen during the last fifteen minutes.

Earle Blakeslee and Wayne Blanks watched the zenith between 13:00 and 14:45 and counted six.

Bertha Brooks and Elise C. Jones faced east and counted fourteen between 13:00 and 17:00.

Daniel N Jones and Ervin N. Edgerton watched the area bounded by lines joining Rigel, Betelgeuse, Sirius and Proeyon from 13:00 to 14:45 and saw two within the area.

Mr. McReynolds faced south and counted three between 14:00 and 14:15. Between 14:30 and 14:45 he saw one.

[blocks in formation]

CHART OF LEONIDS DRAWN BY JAS. B WESTHAVER.

Hazel B. Bush noted the exact times of appearance of ten of the brightest, with a stop watch.

Frank Hiller faced north and saw two between 13:00 and 14:15. Leonora Colmer faced south-east and observed steadily from 13:30 to 16:45 excepting next to the last quarter hour; she counted thirty-three.

The radiant-point was located by a drawing by James B. Westhaver.

A study of the results shows (1) that the south-east was the most favorable direction to face, (2) that few Leonids were seen before 14, on any night; (3) that between 14" and 17h on the night of Nov. 15-16 about the same number were visible in each quarter hour, (4) that the average magnitude was about 3.5, (5) that the absence of the Moon did not materially increase the number seen, and (6) that the best time was probably not later than that predicted by Stoney and Downing, and may have been earlier. After making allowance for

probable duplicates the number seen at University Park is 180, 150 of which came on the morning of Nov. 16. For about a week prior to Nov. 13 the number of telescopic meteors seen while observing nebulae with the 20-inch refractor was about three every four hours, the field of view being 15′ in diameter. This is judged to be at least three times the ordinary frequency of such objects. But there was no evidence from their direction that they were Leonids. Has any one ever studied these telescopic objects, in order to see whether they are the residue of naked-eye meteors, or distinct minute bodies?

CHAMBERLIN OBSERVATORY, UNIVERSITY PARK, Col.

HERBERT A. HOWE.

[ocr errors][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small]

The Leonids Observed at THE ROYAL OBSERVATORY IN LISBON, PORTUGAL,
Nov. 12-17, Local M. T.

OBSERVATIONS AT LISBON, PORTUGAL.

Name of observers; CR: = Campus Rodrigues; 0 = F. Oom. Post office address: Royal Observatory, Tapada, Lisbon, Portugal. Latitude + 38° 42'.5; Longitude = 36m 45 W. Gr.; Time: Local mean.

[graphic][subsumed][subsumed][merged small][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][merged small][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][merged small][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][ocr errors][ocr errors][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][ocr errors][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][merged small][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][ocr errors][ocr errors][merged small][ocr errors][subsumed][ocr errors][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][ocr errors][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][ocr errors][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][ocr errors][subsumed][ocr errors][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][ocr errors][subsumed][subsumed][ocr errors][subsumed][ocr errors][ocr errors][ocr errors][subsumed][subsumed][ocr errors][subsumed][subsumed][ocr errors][subsumed][ocr errors][subsumed][ocr errors][subsumed][subsumed]

* One meteor not Leonid: See Individual Meteors, Nov. 17, 12h 37m.

C. A. DE CAMPOS RODRIGUES, Director.

LISBON, TAPADA, Royal Observatory,

1899, November 25.

« PreviousContinue »