Looking Between Clouds

Inaccurate Forecast

Meteorologists usually give good temperature forecasts, but their cloud cover predictions are often faulty. That's been my personal experience at least. Cloudless skies were forecast on May 28th for my location. Based on this prediction I set up my Seestar for some astrophotography late in the evening. My first target was a trio of closely spaced galaxies in the constellation Leo. I began a planned 30-minute exposure. A few minutes later I glanced up toward Leo and saw a large cloud slowly drifting towards my target location from the west. As time ticked by the cloud edged closer and closer until it began covering the three galaxies. I had to stop the exposure at 29-minutes, so I almost completed the original plan. This particular Leo trio galaxy image is the first image below.

In the previous image the bottom elliptical galaxy is M105, the middle elliptical galaxy is NGC3384, and the smaller spiral galaxy to the left is NGC3389.

The large drifting cloud in the west began to slowly evaporate. East of this cloud the sky remained cloudless, so I moved to another multiple galaxy target in the constellation Virgo. This time I was able to complete the 30-minute exposure shown next. I can see at least nine obvious galaxies in this one field of view and two more dim ones on the edge of visibility!

All eleven visible galaxies are identified in the following labeled image.

All these galaxies are part of the big Virgo Galaxy Cluster which is too large to fit within the field of view. This particular group is part of a beautiful elongated galaxy array called Markarian's Chain. Seestar's small field of view is incapable of capturing all members of the chain, but bagging eleven galaxies at once is still amazing.

Bright elliptical galaxies M86 and M84 are prominent. NGC 4438 and NGC 4435 near the top are actually interacting galaxies. The relatively faint wispy bridge of disrupted material between the pair is barely visible above the background.

By this time Sagittarius had risen high enough to present good targets. I moved to bright nebula M20, the Trifid Nebula, to try a longer exposure than my May 12th attempt. Small troublesome scattered clouds began appearing around the sky, including in the south where M20 is located. Nevertheless, I was able to complete a (non-filtered) 30-minute exposure of M20 between drifting clouds.

The 30-minute exposure above is only slightly better than the 5-minute exposure on May12th. The additional 25 minutes revealed a little more of the blue/white reflection nebula beside the red.

While scattered clouds continued to slowly increase I moved to nebula M16, the Eagle Nebula. Although nearby clouds didn't block this nebula, the two thirds illuminated waning Moon had just risen very close to the horizon. An unobstructed 30-minute exposure is the next image.

Cloud density began increasing. I was able to expose giant globular cluster M22 for only one minute before clouds interfered. This quick image is shown next.

Searching among the diminishing number of cloud gaps, I moved to open cluster M11 in the constellation Serpens. Clouds stayed away during the following 10-minute exposure. M11 is a beautiful sight in a telescope eyepiece. The image scale below makes it look almost as compact as a globular cluster like M22 above. In spite of superficially similar appearances open cluster M11 and globular cluster M22 are quite different. In general, globular clusters are older, contain more stars, and are farther away than open clusters. M11 is about 250 million years old, contains about 2,900 stars, and is about 6,000 light years away. M22 is 12 to 13 billion years old, contains about 500,000 stars, and is about 10,400 light years away.

It was now after 2:00 am. Scorpius had risen to a nice altitude and, for the moment, no clouds were parked there. I took a quick 5-minute exposure of NGC6334, the Cat's Paw Nebula, without the nebular filter.

The Cat's Paw Nebula needs a longer exposure and better centering to show up better. I'll try again sometime.

At this point scattered clouds and moonlight were increasing as the Moon rose higher and higher. It was time to quit at 2:30 am.

I haven't used my nighttime telescopes for visual observing since purchasing Seestar. Seestar is producing much better views than I could hope to see at a telescope eyepiece, especially in my light polluted sky. My eyepieces never reveal the nebular colors that Seestar produces, although individual star colors are much prettier in an eyepiece. It takes so much effort to set up a telescope for visual observing I'm beginning to wonder if it's worth the trouble at this point.