Eclipse calculations and observation in Ottoman astronomy (1800-1922)

Since the 19th century, studies on eclipses have gained a different dimension due to scientific advancements. The British amateur astronomer Francis Baily's observation of irregularities in the Moon's surface during the annular solar eclipse in 1836 is an example. By 1842, helium emission lines became visible with the use of spectroscopes. The first successful photograph of a total eclipse was taken in July 1851 by Johann Julius Friedrich Berkowski at Königsberg. This photograph is important in the history of solar physics, as it was the first photographic record of the upper layers of the atmosphere of the Sun. The French astronomer Pierre Janssen observed the 1868 total solar eclipse in India with his spectroscope, and discovered the emission line of helium, a new and unknown element in the solar spectrum by then. Coronal eclipse spectra taken in 1869 revealed mysterious green and yellow spectral lines so-called 'coronium'. This study aims to examine the lunar and solar eclipses in Ottoman astronomical literature between the years 1800-1922. For this purpose, firstly, the dates of eclipses occurring in this period was determined from NASA-Five Millennium Catalog of Lunar and Solar Eclipses, among these eclipses, those occured in the Ottoman geography were noted. Primary sources such as zijes, annual calendars (takvîm-i sâl), prognostications for the ascendent of a year (ahkâm-ı tâli'-i sâl), and yearbooks (sâlname) were examined to collect information about lunar and solar eclipses of the mentioned period. Moreover, we went through textbooks, translated from European texts to examine the introduction of novelties in astronomy through eclipses between 1800-1922. A study of news published in Ottoman helped us to reveal the effects of eclipses on Ottoman society.