“Micrometric Measurements for Differences of cury and the Sun's North and South Limbs. fraction. Sidereal Time of Observation. h. m. Sun's Limb. Declination of Mer- 3.00 43 18 45.3 B1 3. OBSERVATIONS ON THE COMETS OF 1845 AND 1846. Observations on the Comet of June, 1845, made at the Cambridge Observatory. Lat. 42° 22′ 49′′. Long. 4. 44m. 32". The observed differences of A. R. and Dec. were applied to the A. R. and Dec. of the stars referred to the mean equinox of January 1st, 1846. 1845. d. h. m. s. h. m. S. h. m. 8. June 2 15 39 063 27 32.7 38 15 273 24 59.57 38 03 37.0 4 Bessel's Zone, 448. 3 34 41.0242 05 01.4 17 9 42 35 7 43 17.2 38 15 39 24 09 02 57 14.6+06 04.28 29 7 36 18.3237 53 10.7 3 Bessel's Zone, 493. 3 30 30 8 37 18 50 29 19 19.6 8 37 45.90 28 43 34 3 122222 "The comet was first seen at 14" 15", June 2d. The observations of this morning are made with the spider-line micrometer, and under favorable circumstances. "June 4th. The differences of A. R. were obtained this day from the hour-circle of the equatorial, which reads to single seconds of time. The comet could be seen with the naked eye after most of the stars of the second magnitude had disappeared. It being somewhat cloudy, the length of the tail could not be well determined. The nebulosity was very much condensed and beautifully defined near the head of the comet, the tail was plainly divided into two branches. "June 6th, A. M. The head of the comet broad and full; in the course of six hours, it has undergone a remarkable change, becoming pointed, and appearing with a spur or secondary tail (which is the brightest of the two) of two degrees in length. The axes of the tails are inclined at an angle of twenty degrees, though the estimation is quite uncertain. The principal tail may be traced through five degrees. The observations are made as on the 4th. “On the 9th and 10th, the observations are made with the spider-line and annular micrometers. The changes in the physical appearance of this comet from night to night are particularly interesting. "June 25th. Observed with the spider-line and annular micrometers, the comet being still sufficiently bright to bear illumination; its tail is one or two degrees long. Observations on the Comets of February and May, 1846. Cambridge Mean Solar Time. 1816. d. h. m. 8. A. R. Comet's h. m. 8. Dec. N. Feb.26 08 11 44 1 00 25.7 3 19 17 66 66 66 66 66 แ 21 07 30 16 0 46 57.4 33 45 28 0 48 45.67 34 01 38.1 1 Hist. Cel., p. 20. 31 07 50 45 0 34 15.242 51 32 Apr. 1 07 51 48 0 32 49.4 43 40 50 0 28 25 17 43 38 17.4 2 08 07 58 0 31 20.6 44 30 00 0 29 14.28 44 45 21.2 3 16 24 21 0 29 21.4 45 34 17 0 38 18.36 45 31 19.0 14 08 31 14 0 11 27.5 53 33 350 08 32 67 53 48 09.7 15 08 54 17 0 09 27.854 17 05 0 02 44.56 54 29 05.5 0 09 06.14 54 07 29.6 0 04 55.59 55 00 08.1 0 33 56.57 43 05 35.1 4 3 B. A. Cat., 152. 3 " Bessel's Zone, 443. Bessel's Zone, 444. 2 Hist. Cel., p. 249. 3 23 40 39 91 62 57 42.3 2 23 42 55.73 62 53 14.8 2 66 แ May 4 15 02 17 23 09 51.1 67 21 12 23 12 19 32 67 16 10.8 18 10 48 16 21 20 44.5 74 35 44 21 10 17.07 74 36 46.9 12 09 02 48 6 57 49.3 33 58 13 6 58 06.63/34 04 00.3 5119524 Groomb. Cat., 4142, "[4149. B. A. Cat, 8121. 4. SOLAR ECLIPSE OF MAY, 1845. Micrometric Measurements during the Solar Eclipse of May 5th, 1845. Corrected for Refraction. Cambridge Observatory, Lat. 42° 22′ 49′′, Long. 4. 44m. 325.. Mean Solar Time. d. b. mi. 8. May 5 17 00 43.0 14 51.8+48.4 15 40.2 Diff. of Dec. of the sun's north limb 4 57.5 16 05.340.2 16 45.5 7 19.1 16 17.2 +33.8 16 51.0 and the south cusp. 9 54.01 39.702.3 1 42.0 Diff. of Dec. of the sun's north limb 11 28.3 2 12.1 02.9 2 15.0 and the north cusp. 66 "NOTE. The sky was clear, but the sun's limb was very tremulous. The refraction corrections are somewhat uncertain, the sun being but one degree above the horizon at the commencement of the series. The observations were made by William C. Bond with the 46-inch equatorial telescope (aperture 2 inches), and Troughton's spiderline position micrometer. "The time of ending of the eclipse, expressed in mean solar time for the meridian of this Observatory, as observed by Hon. William Mitchell, with an achromatic telescope, by Tully, of 31-inch aperture and 45 inches focus, was 5d. 17h. 18m. 02.2s. "As observed by W. C. Bond, with a refractor by Troughton and Simms, of 23-inch aperture and 46 inches focus, it was 5 17h. 18. 04.3". "As observed by George P. Bond, with a refractor by Lerebours, having a rock-crystal object-glass of 3 inches aperture and 4 feet focus, it was 5d. 17h. 18m. 04.2". 5. SOLAR ECLIPSE OF APRIL, 1846. Micrometric Measurements during the Eclipse of April 24th, 1846. Corrected for Refraction and for the Sun's Motion in the Intervals 2.01 Diff. of A. R. of sun's 1st limb and preceding cusp. 66 2d limb and following cusp. Diff. of declination of the cusps. 1.80 Diff. of A. R. of sun's 1st limb and preceding cusp. |