iPhone: Mercury, Venus;
D7000: M51 Galaxy (guest), Epsilon Lyrae (Double-Double)
Posted: 30 May 2013
Two more pack rats near the observatory were captured and released on Wednesday, 29 May 2013. Count is now 18 live pack rats and 2 dead ones.
The observatory was opened at 1824 MST, 95°F. The sky was clear but a little breezy. At 1836 MST, I viewed Venus, then Mercury, 83X. I set up for iPhone afocal imaging at 444X. I did video recordings using FiLMiC Pro and used the best frame from the videos. Seeing was not very good. This is Mercury, edited and cropped:
This is Venus, edited and cropped, but at the same image scale as the image of Mercury:
At 1858 MST, still about 30 minutes before sunset, viewed Jupiter, 83X. The equatorial belts were barely visible.
I then slewed to the star Spica and switched to the 12mm illuminated reticle eyepiece. Spica would be used for a training session on manual guiding using the reticle eyepiece. At 1930 MST, my guests arrived. Mary Helen, the lady who I've been helping with her telescope, and who visited Cassiopeia Observatory on 27 May, wanted an image of M51, the Whirlpool Galaxy, which she had seen that night. I offered her the chance to take her own image. But first, she had to learn how to control the telescope for making manual guiding corrections. I showed her how to use the handcontroller slew arrow keys to keep the guide star centered in the "box" in the reticle eyepiece. We started with Spica and progressed to practicing with fainter guide stars over the next hour.
At 2030 MST, I saw the first Kissing Bug of the season. It was terminated with extreme prejudice. Apparently the attempts at preventing Kissing Bugs by spraying and removing pack rat nests near the observatory have not been totally successful. But there are still two more known nests to be removed.
At 2047 MST, we took a break from guiding practice and observed several deep sky objects (DSOs). Using 83X, we observed the globular clusters M4, M5, M68, and Omega Centauri. We also observed the Centaurus A galaxy.
At 2105 MST, I began preparing the D7000 DSLR for prime focus imaging with the 8" LX200-ACF. The camera was mounted on the telescope using the off-axis guider. I then did a focus test on the star Vega using the Bahtinov Mask. As I did each step, I explained what I was doing and why. I then did an unguided framing test exposure of M51, the Whirlpool Galaxy, using a 1 minute, ISO 6400, exposure, seen here full-frame:
I began searching for a suitable guide star. Unfortunately, none was initially found. I finally managed to find a faint one that was usable, but a framing test exposure showed that the galaxy was near the edge of the camera field-of-view (FOV). I decided to go with it. Mary Helen did a guided 1 minute exposure for practice with the faint guide star. (It was at this point in the night that I saw a second Kissing Bug, also terminated.) Additional guided exposures were done by Mary Helen for 2 minutes, 5 minutes, and even 10 minutes. These are the results, which are very good considering that this was her first experience at guiding a telescope while doing astrophotography. The images have been edited and cropped from the full-frame photos:
2 minutes, ISO 6400:
5 minutes, ISO 6400:
10 minutes, ISO 6400:
We completed imaging of M51 about 2230 MST, and my guests left shortly afterwards. Mary Helen seemed to have had a great time at the telescope and I hope she enjoys seeing her first attempts at astrophotography.
The light on the hill to the east was off again this night. Not having this nuisance light on really makes a difference in the quality of the night sky. Thanks neighbor!
At 2247 MST, I viewed Saturn, 83X. Four moons were visible. I then viewed Epsilon Lyrae ("Double-Double" star), 83X. On the previous session I had photographed Epsilon Lyrae using the iPhone 4, and attempted to photograph the stars using the D7000 DSLR. The DSLR images were all overexposed. This night was more successful using the D7000. Using the "Hat Trick" method, ~1 second, ISO 100, I captured this (cropped) image of the four stars:
I ended imaging at 2303 MST. Viewed M57 (Ring Nebula in Lyra), 83X and 222X. The view was very good in the 2" 9mm 100° eyepiece (222X).
The observatory was closed at 2320 MST, 69°F.
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