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DSLR Nebulae Imaging:
Elephant Trunk, Bubble, Pacman, Helix

Posted: 24 September 2016

Although it was clear Sunday night, 18 September 2016, I was unable to open the observatory due to a commitment that night. On Monday, 19 September, clouds from Pacific Hurricane Paine arrived. No rain was received here from that system. Friday, 23 September, there was a 10% chance of rain from another weather system. Got 0.1" from several very brief showers at Cassiopeia Observatory. The sky finally cleared as sunset approached on Friday.

Open: Friday, 23 September 2016, 1806 MST
Temperature: 77°F
Session: 1014
Conditions: Mostly clear, clouds in south, high humidity

Equipment Used:
12" f/8 LX600 w/StarLock
Wireless AutoStar II handset
2" 24mm UWA eyepiece
2" 9mm 100° eyepiece

D7200 DSLR

1818 MST: LX600 ON, StarLock OFF, High Precision OFF.

1821 MST: sunset.

Viewed the planet Venus, low in the western sky, 102X. Gibbous phase obvious.

Viewed the planet Mars, 102X. A limb cloud and a dark surface feature were visible.

1826 MST: viewed the planet Saturn, 102X. The view was not very good due to poor seeing (Saturn was low in the southwestern sky). There was a hint of the Cassini Division; the sky was still bright. 1841 MST: Saturn's moon Titan was now visible, 102X. 1854 MST: Saturn's moons Rhea and Dione were now visible. 1902 MST: tried to see Saturn's moon Tethys, 271X, but it was lost in the planet's glare.

Returned to Mars; seeing was not good enough for viewing at 271X.

1913 MST: viewed the planet Neptune, low in the southeast, 102X. Disk visible.

1926 MST: High Precision ON. Slewed to IC1396 (Elephant Trunk Nebula). A hint of nebulosity was visible at 102X. I had last imaged the Elephant Trunk Nebula on 3 September 2013 using the 8" LX200-ACF and D7000 DSLR. This night I would image it using the 12" LX600 and D7200 DSLR.

While waiting for Astronomical Twilight to end I enjoyed just looking up at the night sky. It was a pretty night with the Milky Way overhead. The Andromeda Galaxy (M31) was a nice naked eye in the northeastern sky.

1935 MST: mounted the DSLR at prime focus + focal reducer. As with all my Deep Sky Object (DSO) images now with the 12" LX600, I focused on the High Precision centering star using a focusing mask. Once centering and focusing was completed and the object was slewed to, the StarLock was turned ON for autoguiding.

My first DSO imaging target was IC1396 (Elephant Trunk Nebula). I did some framing tests but could not seeing the Elephant Trunk in the images on the DSLR screen. I decided to take some longer exposure images and see how well framing worked out during post-processing. Unfortunately, framing was not very good, as seen in this 5 minute, ISO 12800, black-n-white image:


The Elephant Trunk Nebula is only partially visible at the right side of the image. I will make another attempt on the next session.

The next DSO target was NGC7635 (Bubble Nebula) in the constellation of Cassiopeia. I plan to update my Cassiopeia astrophotography photo album with new images from the 12" telescope. This is a slightly cropped, 5 minute, ISO 12800, exposure:


Next was NGC281 (Pacman Nebula) in Cassiopeia. This is a 5 minute, ISO 12800, exposure of the Pacman Nebula:


My last planned DSO image for the night was NGC7293 (Helix Nebula). There were some clouds near the object, and as it turned out, the StarLock autoguiding was slighting impacted by the poor seeing. Some trailing occurred during all the exposures. This is a cropped 2 minute, ISO 12800, exposure:


I plan to redo the image on the next session.

2106 MST: ended DSO imaging. 2117 MST: tried imaging the planet Neptune at prime focus but seeing was too bad. Will try again on a future session.

2129 MST: viewed the planet Neptune, 102X. Then began closing up.

Close: Friday, 23 September 2016, 2139 MST
Temperature: 60°F
Session Length: 3h 33m
Conditions: Clear

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