Cassiopeia Observatory

DSO Imaging: Abell 70, NGC7008, NGC6572,
M72, NGC1491, NGC1333, NGC1514
Posted: 13 September 2012

The observatory had not been opened since 29 August 2012 (2 weeks ago) due to monsoon season cloudy skies and storms. On Sunday, 9 September, we had 0.5" rain in 35 minutes (which allowed me to submit a NWS Trained Spotter report). Later the same day, this monster bug flew past the observatory, as seen on my Live Webcam:

Cloudy skies and monsoon storms continued until Wednesday, 12 September. The observatory was opened at 1819 MST, 89°F. There were clouds along most of the horizon but I had hopes for a clear night. At 1832 MST, a few minutes before sunset, I viewed Saturn, low in the west, 77X and 133X. Other than the ring, no details were visible. Sunset was at 1835 MST. I then began reviewing my selected DSOs for imaging this night. At 1851 MST, viewed Mars, low in the southwest, 77X and 133X. No details were visible. At 1900 MST, slewed to the star Altair, near my first DSO imaging target. The humidity was 42%; not ideal for viewing and imaging.

I began camera preparations, including attaching the Vello Wireless ShutterBoss Timer Remote. At 1924 MST, slewed to Abell 70. I did not expect to be able to see the planetary nebula as it was too faint (Magnitude +14.5), but I wanted to identify surrounding stars. I used SkySafari 3 Pro to show the star field. As the sky continued to darken, I attempted to ID stars, with limited success. At 1930 MST, I attached the D7000 DSLR at prime focus of the 8" LX200-ACF using the Off-Axis Guider. Next, I did a focus test on Altair using the Bahtinov Mask. I then slewed to Abell 70 and began doing a series of framing test exposures while looking for a guide star. I found a faint one and tried a 5 minute exposure. Unfortunately, the star was too faint for accurate guiding. I searched for a better guide star and found a slightly brighter one. This is a cropped, guided, 5 minute, ISO 6400, exposure:

The planetary nebula is visible in the image. The bright area along the top of the "ring" is actually a faint galaxy (PGC187663).

I then slewed to the next DSO, NGC7008, planetary nebula. This is a cropped (as with all the images on this report, it is cropped to the same scale as the other images), 60 second exposure, ISO 6400:

The next target was NGC6572, another planetary nebula. I did several exposures trying to capture this small, bright nebula. I had to keep reducing the exposure length and ISO setting to avoid overexposure. Eventually, I captured this cropped, 5 second, ISO 1600, image:

My next imaging target was M72, globular cluster. This is a cropped, 30 second, ISO 6400, exposure:

Unfortunately, I did not notice that the unguided image was trailed until I was doing image processing on the computer. I will re-take the image on the next session.

I ended imaging at 2046 MST. Removed the camera from the telescope. The humidity was now 57%. I viewed M72 at 77X. Then NGC6572 at 77X and 133X. NGC7008 was viewed at 77X and 133X; it was interesting at 133X using averted vision, with lots of faint structure visible. I then viewed M31 (the Great Andromeda Galaxy) and its companion galaxies M32 and M110, at 133X and 77X. Great views. At 2155 MST, viewed the Double Cluster, 77X, always a nice view. At 2221 MST, the humidity was 60%, with the temperature at 67°F. I then slewed to NGC1491, a diffuse nebula, low in the northeast. It was faintly visible at 77X. I would image it once it was higher in the sky. I then viewed NGC1333, another diffuse nebula, low in the east, 77X, using averted vision.

At 2257 MST, I attached the camera and did a focus test on the star Algol. I then did some framing test exposures of NGC1491 while looking for a guide star. This is a cropped, guided, 5 minute, ISO 6400, exposure:

The next DSO target was NGC1333, diffuse nebula. I did several framing test exposures as I looked for a guide star. At 2343 MST, I took this cropped, guided, 5 minute, ISO 6400, exposure:

I slewed to NGC1514, planetary nebula, low in the east. I would wait for it to rise higher. Humidity was now 62%. At 0001 MST, I began framing test exposures. This is a guided, cropped, 5 minute, ISO 6400, exposure:

I ended imaging at 0018 MST. I then viewed NGC1514 at 77X and 133X. Its nebulosity was just visible and best using averted vision.

Next, I viewed Jupiter, 77X. The four Galilean Moons were visible. The North Equatorial Belt (NEB) was an interesting sight. Jupiter was still low in the east and viewing was not ideal.

I then viewed NGC1048, galaxy, 77X. I attempted to see the supernova 2012ec but it was not visible. Humidity was now 64%, and everything was getting damp. I decided to end the session.

The observatory was closed at 0047 MST, 65°F, humidity 65%. An enjoyable 6h 28m session. It was also a challenging imaging session since most of the objects were faint, as were the selected guide stars. And with the poor seeing due to the high humidity, accurate guiding was difficult.

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