Remembering Earth-that-was
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:
Ports are full of exotic machinery…
I wouldn’t say Mendocino is spectacular, but it is bewitchingly pleasant…
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…
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.
Someday, maybe, I’ll move to a mountain top, with clear dark skies. For now, I live in haze and city lights.
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:
The single exposures aren’t bad on their own. However, the noise in the image is terrible:
(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:
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:
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.
NGC7635, the “Bubble Nebula”, is towards the lower left, and M2 is the open cluster along the upper right side.
The Hubble has, as usual, produced a lovely rendition of the Bubble — I guess we could call it the “Hubble Bubble“.
On a different note, the New Space Telescope has dropped its first images, and they are spectacular, as expected. Ditch astrophotographers such as myself tremble in awe. Several side-by-side comparisons of HST and NST images show wonderful improvements in clarity and detail. Stephan’s Quintet has special significance to me because it is the most difficult object I ever saw visually, back many years ago when my eyes were better and I had a 10″ Dobsonian. It was only discernable with averted vision, but definitely there.
However, the Hubble images are still as exquisite as they ever were. The universe has wonders at every scale — it is a fractal of wonder. The Hubble reveals wonders at its scale. The New Space Telescope reveals wonders at a different scale. And My Little Telescope (MLT) reveals wonders at its scale.
Another heroic image 🙂 — 18 hours with a small telescope and poor conditions. Post-processing is minimal — just some brightness and contrast adjustments in gimp to minimize the distracting sky glow.
Life these days is extremely depressing.
Morbius: ‘My poor Krell. After a million years of shining sanity, they could hardly have understood what power was destroying them.’
This image is my deepest view so far of M51. About twelve hours total exposure time, but it represents much more telescope time because I’ve discarded many hours worth. The night before last, for example, out of five hours total time I dumped four, because after I went to sleep fog rolled in, and all the exposures were flat gray.
A close crop:
The dark red coloration is consistent with images on the web, so I presume it is a reflection of reality.
How did this happen? What does it mean?
As fate would have it, more light was available last night. Not great, but better.
Here’s the larger view:
NGC6946 is dim. I only had about three hours total exposure; it would be better with twice that. Unfortunately, the weather is sketchy, and I probably won’t be able to collect those photons any time soon.
Stellarium has several fanciful names for NGC6939 — the “Ghost Bush Cluster”, the “Flying Geese Cluster”, and the “Silk Fan Cluster”. I prefer “Silk Fan Cluster”.
This image was cropped to balance the two objects. A closer crop of the galaxy shows lots of potential, but it would take time and good conditions to do it justice:
