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D7200 DSLR imaging: Dumbbell Nebula, Pleiades

Posted: 12 November 2015

Clouds began appearing on the western horizon shortly after sunrise on Tuesday, 10 November 2015, as another weather system approached. The sky cleared on Wednesday, 11 November, but with a freeze warning for overnight. Winter is coming!

Open: Wednesday, 11 November 2015, 1816 MST
Temperature: 56°F
Session: 879
Conditions: Clear

Added the focal reducer to the 8" LX200-ACF telescope. Then viewed M27 (Dumbbell Nebula, planetary nebula), 53X. Began preparing to image it once astronomical twilight ended. Slewed to the star Altair, which would be the focus test star, and mounted the D7200 DSLR at prime focus + focal reducer + extension + off-axis guider. Did the focus test on Altair using the Bahtinov Mask. Slewed to M27. It was visible in the camera viewfinder. Searched for a guide star; found a faint one (not ideal) that provided reasonable framing of the Dumbbell Nebula. This is a cropped, 3 minute, guided, ISO 5000, exposure:


1937 MST: slewed to M45 (Pleiades), still slightly low in the eastern sky. Had to rotate the camera to get the entire cluster in the camera field-of-view (FOV) with the focal reducer. Then did some short unguided exposures as I could not locate a good guide star that provided good object framing with the Pleiades nearly filling the entire FOV. This is a 2 minute, unguided, ISO 5000, exposure:


This short exposure captured some nebulosity.

I plan to re-image both objects on the next session and try for better guide stars.

1955 MST: ended imaging. Removed the camera and focal reducer from the telescope. Viewed M45, 83X.

Then did a sky quality reading as a test of a new beta version of the iOS app "Dark Sky Meter". Passed the results to the developer.

It was getting breezy at this point so decided to close up.

Close: Wednesday, 11 November 2015, 2026 MST
Temperature: 45°F
Session Length: 2h 10m
Conditions: Clear, breezy

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