Giovanni Batista Donati (1827 - 1873) made the first spectroscopic observations of a comet tail (from the small comet, Tempel, 1864 II) on 5 August, 1864. At a distance from the Sun the spectrum of a comet is identical to that of the Sun, and its visibility is due only to reflected sunlight. Donati showed that comet tail formed close to the Sun contains luminous gas. In the spectrum of light from the comet tail, Donati saw three absorption lines bands superimposed on a continuous spectrum, which he named alpha, beta and gamma, and are now known as the Swan bands. These bands were also seen in a comet tail viewed by Pietro Secchi in 1866. Sir William Huggins (1868) identified that these were due to the presence of carbon (molecular carbon, C2). Reference: radjournal/articles/History/August/August.htm, Retrieved 26 June, 2012
Posted on: Tue, 05 Aug 2014 03:30:00 +0000
Trending Topics
Recently Viewed Topics
© 2015