| Description | Large, intermediate spiral galaxy in Cam, discovered by William Herschel on 1 November 1788. GA Tammann and Allan Sandage calibrated Cepheid variables in NGC 2403 in a.1968 paper using the 200" Mt Palomar Telescope, making it the first galaxy beyond the Local Group within which Cepheid's were used in the Hubble constant distance calculation. Analysis of Cepheid's increased the estimated distance to approximately 8 million light years. Similar to M33, NGC 2303 contains numerous HII star-forming regions, one of which is designated NGC 2404. The gallery includes an additional, heavily stretched version of the image that makes these regions more visible. |
