German astronomer (1893-1960) who worked at Mount Wilson Observatory from 1931 to 1958, where, during World War II, he was able to resolve stars in the center of the Andromeda galaxy for the first time. With colleague Fritz Zwicky, Baade identified supernovae as a new category of astronomical objects. ALS, one page, 8.5 x 11, Mount Wilson Observatory letterhead, October 29, 1945. Letter to Cambridge astronomer F. J. M. Stratton, in part: "The reference to the shadow moving across NGC 2261 must be in the Mt. Wilson Report for 1937/38. I enclose 2 prints which illustrate this remarkable phenomenon. I have my doubts whether the dip in the light curve of Nova Herc has anything to do with obscuration…It seems to me that the explanation given by Grotrian is the correct one. There are some obscurities in Grotrian's description but they are easily removed when one really follows his basic idea. In fact if one combines Pike's and Grotrian's ideas of the ejection process one gets a very clear picture of a nova outburst." In fine condition.
