Dmitry Ivanovich Dubyago (Дмитрий Иванович Дубяго in Russian) (September 21 (N.S. October 3), 1849 - October 22, 1918) was a Russian astronomer and expert in theoretical astrophysics, astrometry, and gravimetry. September 21 is the 264th day of the year (265th in leap years). ... In Britain and countries of the British Empire, Old Style or O.S. after a date means that the date is in the Julian calendar, in use in those countries until 1752; New Style or N.S. means that the date is in the Gregorian calendar, adopted on 14 September... October 3 is the 276th day of the year (277th in leap years) in the Gregorian Calendar. ... 1849 was a common year starting on Monday (see link for calendar). ... October 22 is the 295th day of the year (296th in leap years) in the Gregorian Calendar, with 70 days remaining. ... 1918 (MCMXVIII) was a common year starting on Tuesday of the Gregorian calendar (see link for calendar) or a common year starting on Wednesday of the Julian calendar. ... An astronomer or astrophysicist is a person whose area of interest is astronomy or astrophysics. ... Theoretical astrophysics is the discipline that seeks to explain the phenomena observed by astronomers in physical terms with a theoretic approach. ... This article does not cite its references or sources. ... Gravimetry is the measurement of a gravitational field. ...

A crater on the Moon is named after Dmitry Dubyago. Dubyago is a lunar crater that lies in the eastern part of the Moon, so that it appears significantly foreshortened when viewed from the Earth. ... Bulk composition of the Moons mantle and crust estimated, weight percent Oxygen 42. ...