. The Adolfo Stahl lectures in astronomy, delivered in San Francisco, California, in 1916-17 and 1917-18, under the auspices of the Astronomical Society of the Pacific. o orbits: Meteors of Novem- Orbits of ber 13 Comet 18661 Perihelion passage November January Longitude of perihelion 56° 25 .9 60° 28 .0 Ascending node 231 231 Inclination 17 17 Perihelion distance ^ Eccentricity Semi-major axis Period of revolution years years Direction of motion retrograde retrograde It is impossible to doubt that these
. The Adolfo Stahl lectures in astronomy, delivered in San Francisco, California, in 1916-17 and 1917-18, under the auspices of the Astronomical Society of the Pacific. o orbits: Meteors of Novem- Orbits of ber 13 Comet 18661 Perihelion passage November January Longitude of perihelion 56° 25 .9 60° 28 .0 Ascending node 231 231 Inclination 17 17 Perihelion distance ^ Eccentricity Semi-major axis Period of revolution years years Direction of motion retrograde retrograde It is impossible to doubt that these November meteors and thecomet referred to were travelina: in the same orbit. 48 The Adolfo Stahl Lectures The so-called Lyra meteors are visible atout x\pril 20 eachyear. It was noticed in 1867 by Weiss that the orbit of theLyra meteors is essentially identical with that of Comet 18611. Bielas comet, to which we have referred, when last seen in1852, as a double comet, was expected to return in 1866 andagain in 1872, but it was not seen then, nor later. A meteorshower of moderate intensity was observed on November 27,1872, movino in the orbit of the lost Fig. 4. Orbits of Meteoric Swarms, which are known to beassociated with comets. Not to dwell upon the remarkable identities of the orbitsof the four meteor swarms, respectively, with the orbits of thefour comets (Fig-. 4), two of which have disappeared, andthe other two, of relatively long periods, which may neverreturn, we express the prevailing opinion of astronomers insaying that the meteor streams have actually resulted fromthe disintegration of the four comets. Alexander Herschelhas prepared a list of seventy-six meteor streams whose orbitsagree fairly closely with the seventy-six comet orbits. A cer-tain proportion of the suspected identities probably represent Fig. 1—Spectrum of Comet Daniels, 1907.
Size: 1826px × 1368px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectastronomy, bookyear19
