Star Fields and Clusters
This set contains observations of star fields and clusters. The plates were obtained through two astrographic cameras coupled to the main 649.9cm tube of the equatorial telescope of 45.8cm objective lens aperture. These are two cameras made by the english manufactures Taylor, with the diameter of the objective lens of 25.44cm and focal distance of 17.28cm.
Note: The images of scanned plates have their names formed, initially, by three letters associated to a number to facilitate their location in the digital database and physical archive of the Observatório Nacional library.
