Henrietta Leavitt non era sola nel suo lavoro. Presso l' Osservatorio di Harvard, tra la fine del XIX o secolo e gli inizi del XX o , lavorarono diverse decine di donne, divenute note come le Harvard computer , assunte per svolgere i compiti più tediosi dell' analisi dei dati astronomici e pagate circa la metà dei colleghi maschi. Henrietta era una di queste. Altre tre Harvard computer sarebbero entrate a pieno titolo nella storia dell' astronomia: Annie Cannon, Williamina Fleming, ed Antonia Maury. Il loro lavoro è legato the birth of stellar spectroscopy, one of the first steps of 'modern astrophysics.
in 1872 had obtained the first photograph of the spectrum of a star during the 80s or nineteenth century, the study of stellar spectra was a new frontier. All ' Harvard College Observatory a large prism was used to disperse the light and get the spectrum of a field with many stars at once. L 'Observatory was being taken to' systematic observation of the brightest stars in both 'southern hemisphere, which in' northern hemisphere and the data were collected in huge quantities for astronomers today, and most of the work of cataloging and analyzing data was done by Harvard computer.
These include Williamina Fleming contributed to the establishment of a first catalog appeared in 1890, which lists more than ten thousand stars, location, magnitude and spectral type (the star would become more than 220,000 in 'Henry Draper Catalogue published between 1918 and 1924 by Annie Cannon and Edward Pickering). In the course of their work, is that Annie Cannon Williamina Fleming discovered hundreds of variable stars and novae many stars, the latter revealed by their emission line spectrum widened.
But the true Grail of computer Harvard was a classification of stellar spectra in a number of types spectrum that included most of the stars, and were linked to their physical properties. Although there have classification systems of stars, including one developed by Pietro Angelo Secchi, they were designed for the 'visual observation and inadequate to explain the features of the spectra recorded on photographic plate. Annie Cannon redefined using the spectral classification of letters' alphabet, as Fleming had done, but more subtly, creating a sequence-dependent surface temperature of stars. Antonia Maury, the youngest of three, completed the classification and was the first to find that absorption lines could appear to be widespread che estremamente nitide. L' importanza delle sue osservazioni sulla larghezza delle righe spettrali divenne chiara con la scoperta delle stelle supergiganti.
La sequenza di tipi spettrali venne descritta da Annie Cannon nel 1912, nell' articolo Classification of 1,477 stars by means of their photographic spectra . Nella sostanza, è quella in uso ancora oggi, O B A F G K M ...
Proprio in questi giorni sul blog in lingua inglese corrispondente a Professione astronoma, ci si chiedeva quale tra le astronome del passato o contemporanee potesse essere una forte sorgente di ispirazione. Penso che tutte le Harvard computer , non solo quelle divenute famose, possano essere source of inspiration. But above all I think be Annie Cannon, Henrietta Leavitt and as suffering from profound deafness. Despite this considerable disadvantage, those who knew her says a cheerful and serene. His dedication to work on an unprecedented amount of data has allowed us to take a major step forward in understanding and lasting of our Universe. I think it's an example that still should not be forgotten.
Paola Marziani
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