Isaac Roberts astrophotos

This first group of photos were published in

Isaac Roberts, A Selection of Photographs of Stars, Star-Clusters and Nebulae, 1890, The University Press, London . Vol. 1

All these astrophotographs were taken with a 20" reflector. Unless otherwise noted the scale of the images is 1mm equals 24 arcseconds.

	M34 1 hour exposure taken on 12/26/1892
	M35 66min exposure taken on 2/7/1893
	M44 90 min exposure taken on 2/13/1891
	M103 60 min exposure taken on 12/23/1892
	Cygnus star field 1mm =31.7 arcseconds Right Ascension 19h 41m 14s to 19h 50m 26s Declination 34d 28’ to 36d 38’ 1 hour exposure taken on 8/14/1887
	Double cluster in Perseus 3 hours exposure taken on 1/13/1890
	M42- the Great Nebula in Orion 81 minute exposure taken on 12/24/1888
	M42- the Great Nebula in Orion 205 minute exposure taken on 2/4/1889
	M45--the Pleiades 4 hour exposure taken on 12/8/1888
	Veil nebula 4 hour exposure taken on 9/28/1891

The second group of astrophotographs were published in

Isaac Roberts, Photographs of Star-Clusters and Nebulae, 1899 Knowledge Office, Vol. 2.

	M1 1mm=8 arcseconds 60 min exposure taken on 1/25/1895
	Veil Nebula 1mm=30arcseconds 2 hours 55 min exposure taken on 11/4/1896
	M51 1mm =12 arcseconds 90min exposure taken on 4/15/1898