M 40

Urban Astronomy: Observing the Messier Objects from the City Not Available
The Nature of the Double Star M40 WNC 4 is listed as a double star in the literature dating back to 1869. Charles Messier catalogued this object as M40 in his famous list. Using new TYCHO-2 and other data, the minimum distance to the pair is found to be 170 +/- 70 pc. The new parallax and proper motion data failed to support any assumption that the two stars in the pair are gravitationally connected. The observed position angle changes of the pair can be explained by the TYCHO-2 proper motions of two optically aligned stars instead of real orbital motion. If the components were gravitationally connected, the data suggest a minimum separation of 5,000 AU, and a minimum period of 232,000 years, which is highly improbable for a true visual binary star system.
Shoot-out at Star Hill Inn Not Available
Catalogue des nebuleuses et des amas d'etoiles. Not Available

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