Dragonfly Cluster, aka the Owl Cluster

Dragonfly Cluster
Dragonfly Cluster

By the naked eye, the night sky is only tiny points of light, occasionally blotted out by the moon. The enormous clouds of gas and dust, the majestic galaxies, are mostly invisible. So sometimes it’s nice to just see stars.

While the cluster looks more like an owl, I can also see the two bulbous eyes of a dragonfly and maybe a hint of a slender body.

Reprocessing reprocessing…

I’ve purchased a new plugin for PixInsight, called “BlurXTerminator” (BXT). It uses AI trained on astronomical data to sharpen stars, and the edges of nebula.  It seems to work pretty well.

Here is a reprocessed version of the “Cygnus Wall” (part of NGC7000, the North American Nebula):

The "Cygnus Wall", an irregular band of nebulosity in the North American Nebula.

BXT actually works. This image is significantly sharper and more detailed than my previous version (though you have to look close). I worry if the new detail is “real” or manufactured? Is this picture a more accurate representation of reality?

Here is a reprocessed version of M81 and M82. The data for this image was collected back in February.

M81 and M82, neighboring galaxies

The major problem with this image is the overexposure of the central region of M81. One of these days I will work out the technique for fixing that, but for now, this isn’t bad. Once again, if you look closely, the enhanced fine delicate detail is apparent.

On a completely different topic, I started reading “A Tale of Two Cities” recently. Man, it’s so clear that Dickens was being paid by the word…


Callao, Lima is a very busy port, and since our ship didn’t move for two days, we had plenty of time to watch it. When we arrived, there were several hundred new cars parked, fresh off the boat; the next day, they were gone. My attention was drawn to these:

Giant grain hopper

Ports are full of exotic machinery…

From Lima, Peru

We arrived at the Lima international airport, and were whisked to our hotel, the JW Mariott, to recover from our 24-hour ordeal flying from SFO. The next morning we transferred to the ship where we would live for the next 21 days, cruising the Chilean fjords, then around Cape Horn.

The plan was to depart that evening, but it didn’t work out — shortly after our arrival at the airport, a serious accident happened on the single runway and blocked all air traffic for a day. There were no flights for disembarking passengers to fly home, and the passengers on arriving flights couldn’t land and thus couldn’t join the ship.

Information about the accident has been hard to find. There was a plane taking off, and a firetruck, possibly on a training mission, collided with the tail section. Two firefighters were killed, but everyone on the plane survived. However, the plane couldn’t fly, and the crash would have to be investigated. The wreckage blocked the runway for more than a day. Flights were diverted or canceled, and temporary lodging had to be found for stranded passengers from literally around the world. Several hundred people were affected.

The upshot was that the ship delayed its departure for two days while the cruise company scrambled to make new arrangements for their customers. We were lucky to get on the ship at our scheduled time.

Mendocino Coast

I wouldn’t say Mendocino is spectacular, but it is bewitchingly pleasant…

The sun looking at us from a great distance.

Catching up on astrophotos

The days are clear, but the mist rolls in about midnight, so it’s been difficult to take any pictures. Here are a few from the last month or so…

NGC7635 (the Bubble Nebula), M52, and NGC7538

NGC7538 is sometimes called “The Brain” or “The Northern Lagoon”. It’s the bright knot at the top center. M52 is the open cluster bottom left of center.

IC1340, part of the Veil Nebula in Cygnus. Called “The Bat” for some reason.
Another view of the Bat, IC1340. More exposures.
IC1396, the Elephant’s Trunk. It’s poorly framed…
IC1396B - Elephant's Trunk
Better framed version. Couldn’t get the colors right.
IC63, The Ghost Nebula — for its shape.

Someday, maybe, I’ll move to a mountain top, with clear dark skies. For now, I live in haze and city lights.

The Witch’s Broom

NGC6960, The Witch's Broom
NGC6960, The Witch’s Broom Nebula (part of the Veil Nebula

This image is from 18 5-minute exposures. With luck, I’ll get some more tonight and sharpen it up a bit.

Edit: As promised, here’s the same image with additional exposures:

NGC6960, The Witch's Broom
…with 65 sub-exposures

The single exposures aren’t bad on their own. However, the noise in the image is terrible:

NGC6960 raw exposure
Single exposure with all defects exposed

(The electronics in the image sensor caused the odd artifact along the upper right edge.)

For your convenience, here are a couple of 100% crops of the single vs. combined images.

Single exposure:

100% crop
Single exposure, 100% crop

Note the many tiny bright blue dots. These are defects in the image; pixels that fired inappropriately. There are many other fine grain flaws, but the blue dots stand out.

…with 65 sub-exposures:

100% crrop
Combined multiple exposures, 100%crop

The blue dots are gone.

When I started this hobby I thought the purpose of multiple exposures was to make dim objects brighter. But it isn’t — the goal, the magic sauce, is noise reduction. With many exposures, the errors cancel out, and a clearer view of the underlying reality emerges. We hope.

In the single exposure above, the inaccuracies of the individual sensor elements give a gritty character, as if the image was a sand painting made with somewhat impure sand. The image that results from combining the 65 sub-exposures has much less of that gritty appearance.

Comet K2

Comet K2
Comet C/2017 K2 Panstarr next to Globular Cluster M10

M10 is left of center; K2 is a little lower and on the right side. This picture was taken 14 Jul 2022, just about the comet’s nearest approach to Earth.

I took the picture under desperate circumstances; high fog was crashing my party, and I only had about a half hour to collect these photons. Even worse, the telescope was having trouble pointing (something I will need to troubleshoot when I’m not under time pressure).

It’s a standard weather pattern for this time of year — beautifully clear during the day, with high fog / low clouds developing as the night cools down. It has been like this for a couple of weeks.