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DSLR imaging: NGC2264, Asteroid Edmondson, & NGC2261

Posted: 13 January 2018

Friday afternoon, 12 January 2018, I attempted to see the launch of a Delta 4 rocket from Vandenberg AFB, California. I didn't have any high hopes of seeing this daytime launch and certainly did not expect anything spectacular like the 22 December 2017 sunset launch of a SpaceX Falcon 9 from VAFB. While waiting for the launch I did get this photo of a red-tailed hawk:


As expected, the daytime launch was not seen. Unforecasted clouds in the western sky didn't help.

Open: Friday, 12 January 2018, 1818 MST
Temperature: 70°F
Session: 1185
Conditions: Mostly clear

Equipment Used:
12" f/8 LX600 w/StarLock
2" 24mm UWA eyepiece
1.25" 15mm eyepiece
Focal Reducer

D7200 DSLR

1823 MST: LX600 ON, StarLock OFF, High Precision OFF. SYNCed the AutoStar on the star Aldebaran.

Slewed the 12" telescope to NGC2264. I would image it after the end of Astronomical Twilight.

1844 MST: decided to relax on the observatory patio bench while waiting for the sky to get darker. Always nice to watch the stars come out. 1908 MST: returned to the telescope.

1918 MST: mounted the D7200 DSLR at prime focus + focal reducer. Focused on the star Aldebaran. Then did a series of framing test exposures of NGC2264 using the iOS app AstroAid. Once I was happy with the framing I took this StarLock autoguided, 5 minute, ISO 6400, White Balance 3570K image (slightly cropped):


The Cone Nebula is faintly visible at the left and the bright blue Fur Nebula is at the right. This was actually the second 5 minute exposure of NGC2264 I took this night. The first was photobombed by a satellite.

1947 MST: returned to Aldebaran and rechecked the focus in case it had changed due to the dropping temperature; it hadn't.

1949 MST: saw a very bright meteor low in the northeastern sky.

2000 MST: Wi-Fi ON. Used SkySafari 6 Pro on the iPhone to GOTO Asteroid (1761) Edmondson. I had previously made an attempt to image this faint (Mag +17.2) asteroid on the previous night and needed an image 24 hours later to check for motion. After slewing to the asteroid I realized I had not changed the camera orientation to match what it had been on the previous imaging of the asteroid. Oops. Returned to Aldebaran, quickly rotated the camera, refocused. Fortunately I completed the reconfiguration in time. 2010 MST: took a StarLock autoguided, 5 minute, ISO 6400, WB 3570K exposure. During post-processing I did a "blink compare" of the images from the two nights. I confirmed I was able to image Asteroid (1761) Edmondson. As I had mentioned on the previous report, Dr. Frank Edmondson was the Chairman of the Indiana University Astronomy Department when I was an undergraduate student 1966-70, and during my four years at IU I worked on the IU Asteroid Program. Here are the two images with the asteroid location marked:

Asteroid Edmondson, 11 January 2018

Asteroid Edmondson, 12 January 2018

The galaxy at the top is IC1723 (Mag +14.02). A smaller fainter galaxy is visible near the center of the image.

This animation clearly shows the movement of Asteroid Edmondson in 24 hours:

Asteroid (1761) Edmondson

On future sessions I plan to try to image other asteroids named after some of the professors I knew while an undergrad. Most of these are also very faint and so will be challenging.

2030 MST: removed the focal reducer, focused on Aldebaran, and slewed to NGC2261 (Hubble's Variable Nebula). When I removed the reducer I heard a rattling sound. I discovered that a lens retaining ring was loose. I re-tightened it.

After doing some framing test exposures (the faint nebula was difficult to see in the camera viewfinder), I took this StarLock autoguided, 5 minute, ISO 6400, White Balance 3570K image (cropped):

NGC2261 (Hubble's Variable Nebula)

I had hoped to compare an image of NGC2261 I took in 2012 using the 8" telescope with this one captured using the 12" telescope to see if any changes were evident. Unfortunately, the difference in equipment and exposures made the comparison impossible.

2046 MST: StarLock OFF. Ended imaging. Removed the camera.

2056 MST: viewed NGC2261 (Hubble's Variable Nebula), 102X. Then viewed M79 (globular cluster), 102X and 163X.

2103 MST: LX600 OFF.

Close: Friday, 12 January 2018, 2118 MST
Temperature: 52°F
Session Length: 3h 00m
Conditions: Clear

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