Author: Andrew

An electrical engineer, amateur astronomer, and diver, living and working on the island of Hawaiʻi.

Shoveling Snow in a Tropical Paradise

I shoveled snow in Hawaiʻi today.

Not the first time I have shoveled snow here. Somehow the novelty of snow in a tropical paradise never grows old. Not that shoveling snow at nearly 14,000ft gets any easier. The weekend storm left a foot of fresh snow on the mountain. As the Monday crew never made it to the summit, it fell to those of us working Tuesday to clear out the snow for access.

It was only a foot of snow? Not too bad? The snow came with 120mph winds, stripping the slopes bare and piling a three foot deep, fifteen foot wide drift in front of our loading dock and main doors. That was going to be a chore.

We needed power. The grader was working to clear the IRTF access road just above us. As the crew moved the vehicles I made a trip up to intercept the grader. At my request the driver joking asked how much cash I had. No. Beer? No. I offered cookies and the deal was made. A few minutes later the grader was clearing much of the snowdrift in our way.

Shoveling Snow
The crew shovels the loading dock clear while the OMKM grader clears a troublesome snowdrift.

Postcard from the Universe – Rosette Revisited

For my first pass on the Rosette I used about an hour of data. Ten four minute exposures, ten one minute exposures and ten 15 second exposures. The stack is designed to capture a wide dynamic range by using several different exposure lengths. Multiple images taken at each exposure to reduce the noise inherent in long exposure astrophotgraphy. All of this data is aligned and stacked to produce the final image.

The Rosette Nebula
The first pass at the Rosette nebula with one hour of data, 10x240s+10x60s+10x15s @ISO6400
When looking at the result it was apparent that I had not been successful in reducing the noise far enough. More exposure time was needed. The shorter exposures were not the problem, I needed more of the longer four minute exposures to reach the faint nebulosity.

The next night I acquired and shot again, another 24 exposures on the Rosette, another 1.6 hours of exposure. A planned astrophoto outing to the MKVIS at 9,200ft elevation offered a chance to get even more high quality exposures. This time I got 30 more exposures, another two hours of total exposure time.

Combining all 3.8 hours of exposure resulted in a notably nicer image. The noise in the fainter sections of the image is pleasantly reduced. It should be with 54 four minute exposures used.

I need to do some sort of systematic comparison of the data gathered in my driveway versus the data obtained at the MKVIS up on the mountain. Having a series of exposures taken with the same gear, on the same target, and at the same time of night just a few days apart should allow a reasonable comparison. I was unable to expose any longer at the VIS despite the colder temperatures (the camera was about 10°C colder). How much better is the VIS? Can I get data nearly as good without packing up the gear and heading up the mountain?

The Rosette Nebula
The Rosette Nebula, NGC2237, NGC2238, NGC2244, NGC2246, Canon 6D and TV-76mm, 54x240s+10x60s+10x15s @ISO6400

Geomagnetic Activity and Airglow

Taking starscape photos last week I was surprised at the intense red glow appearing in the photographs. All across the southern sky were glowing areas of sky, here and there dark rifts cut through the glow. Set beside the Winter Milky Way it created beautiful photographs.

Airglow or auroral glow?
Airglow or auroral glow? An odd red glow in the photos during a strong geomagnetic storm.

The airglow was intense enough to be visually seen when I stepped away from the camera and let my eyes adapt to the darkness. Away from the Milky Way, in what should be dark sky, a faint red glow pervaded. I wondered what was going on, the normal airglow over Mauna Kea is quite faint and usually very green.

I was even further surprised when I later found out that a strong geomagnetic storm was in progress that night. Kp=6 conditions from back to back CME’s were creating strong aurora over Canada and the upper US.

Was I seeing some sort of auroral glow? In Hawaii? At 20°N latitude? This did not seem likely, but something unusual was occurring!

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A Night of Shooting in the Dark

The plan was to do some astrophotography Saturday night. The weather forecast forced a re-schedule, a winter storm arriving Saturday afternoon, Friday it was to be.

The Pleiades
The Pleiades, M45, with the Canon 6D and TV-76mm
The timing proved to be excellent, Mauna Kea providing glorious skies Friday night. Clouds hovered over the side of the mountain on arrival, but there was no worry. These were the sort of clouds that would vanish with the daylight. Anxious tourists wanting to see through the telescopes repeated the same question, will the clouds go away? I answered the questions with the relaxed assurance of experience of years on Mauna Kea, and continued to set up the gear. The clouds didn’t even last as long as I expected, dissipating as the sun settled into the horizon.

Setting up at the Mauna Kea VIS means a crowd of people. Hundreds of tourists that have come to enjoy a dark Mauna Kea Sky. I was joined by Raymond, a Hilo amateur also looking to take some photos. We setup side by side in a parking space just off the patio where the VIS was setting up their telescopes for the night. We would be in the center of the crowd for a while.

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