M40 / WNC 4

Designation(s)M40, WNC 4
Object Type(s)
Relevant Catalog(s)All (Chron), Messier
Obs. Lat/Long42° 17', 073° 57'
ConstellationUrsa Major
Date and Time Observed2024-04-20 21:51:00
InstrumentSeeStar S50 f5.0-250mm FL
CameraBuilt-in IMX462 Sensor
Image DetailsTotal integration time was 4m. Exposures 10s@auto gain. 93% moon; intermittent high clouds. Darks subtracted, no flats. .
DescriptionFift capture of a strange evening when it rained right up to the moment it cleared around 9 PM. Because of the 93% moon, I had planned to capture a number of Messier objects, mostly clusters, and decided to observe with the SeeStar. This is an "optical" double, two stars that just happen to appear close together from Earth's vantage point. Messier himself found it looking for a nebula reported by another astronomer in the same area of the sky. It's the only double star in the Messier Catalog, possibly because his telescope didn't resolve them clearly.
Catalog Links
 Messier Listings 
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