Shooting in the Dark

A supernova, a comet, a new camera and a dark night.

I have had the Canon 60D for a while now. Since April in fact. It was my main carry camera in Alaska this summer. This was the camera used to produce the laser shots and videos that were published far and wide. But I have never used the camera on a telescope. A new Moon observing weekend is an opportunity to change that.

Astrophoto Setup
The NexStar 11″, the TV76mm and a Canon 60D setup for astrophotography at the MKVIS
I have recently re-assembled my astrophotography rig in the garage. But that rig has some technical issues that need to be solved before it is ready to use. Instead I packed up the NexStar 11″ scope, a scope usually used for public observing, but also a nice photographic platform. Piggyback the TeleVue 76mm atop the larger scope, attach the 60D and I am ready to shoot. Well? Maybe a bit more work than that. With alignments, focusing and more it was an hour before the first exposure.

While my camera was busy shooting sequences, I wandered around and visited with the other folks enjoying the night. A few peeks through other scopes at favorite objects was about all the visual observing I did. There were a couple groups using cameras without telescopes to shoot stars capes under the dark sky. We traded hints as multiple cameras worked the night.

An orange glow in the clouds betrayed new lava flows on Kilauea. Even thirty miles away we could make out bits of a channelized a’a flow. The pair of binoculars I had brought became one of the most popular optical instruments around.

I was using the rig without any autoguiding, as a result guiding errors spoiled a number of exposures. I kept the exposures short, and shot bright objects. I have sequences to process of a lot of old favorites… M31, M42, a few open clusters like M11 and M38, the Pleiades and more. Just before dawn I even shot a sequence of the Tarantula Nebula skimming the slope of Mauna Loa. Two 8Gb SD cards filled and part of a third. I will be some time processing the many images taken through the night. There is even some video of Jupiter and Mars to process into high resolution planetary images.

There were three telescopes still operating when dawn appeared. Maureen, Cliff and myself watched as the sky grew bright and a thin crescent Moon rose above the slopes. Even then we spent a little time observing and photographing the Moon or Mars as the stars disappeared. We were still breaking down gear as sunlight swept the hillsides around us. Tired and yet elated we greeted the Sun.

The usual suspects setting up gear for a great night of observing on Mauna Kea...

A Very Dark Night

Planning a night of observing is a challenge. There is the choice of equipment, setting up observing lists of objects to target. And then there is deciding where to go.

Finding a dark spot can be a challenge in Hawai’i. Almost every bit of land is gated and tied up in bureaucratic rules. We often use the area around the Mauna Kea VIS to observe. Located at 9,000ft on the south side of Mauna Kea the area has much to recommend it for amateur astronomy. This land is under the administrative control of OMKM, who actively support astronomy, both professional and amateur. But the area does have a number of lights, and there is regular vehicle traffic, even in the middle of the night. Thus I have been actively looking for other places.

Ready for Dark
The 18″ setup at 9000ft on the side of Mauna Kea
The area around the MK VIS is state land, under the control of the State of Hawaii Department of Land and Natural Resources. Just below the VIS is the start of a back road that almost entirely circles the mountain, R-1, also part of the Na Ala Hele trial system, a road designated for public access. Perfect! All I need is a place just enough out of the way to avoid any lights or activity in the night.

State land is an interesting issue in Hawai’i. No camping is allowed outside of designated sites, period. But, according to the DLNR administrative rules it is not camping unless you are… “in possession of a backpack, tents, blankets, tarpaulins, or other obvious camping paraphernalia, any time after one hour after sundown until sunrise in a forest reserve” (Section ยง13-104-2 Hawai’i Division of Forestry and Wildlife). I made certain I had no “camping paraphernalia” with me. I am merely picnicking… in the middle of the night.

Continue reading “A Very Dark Night”

Postcard from the Summit – Red Bow

Waimea is a place of rainbows. So common are they here it is a rare day that goes by without at least one rainbow.

But what does a rainbow look like at sunset? When the Sun’s light is reddened by passage through so much air and haze. The bow will begin to lose all color except for red, this creates a red bow…

Red Bow above Mauna Kea
A snow covered Mauna Kea at sunset as seen from Wiamea, with a bit of a red sunset bow above the western slope

Shoveling Snow

Monday I spent the day on the summit, I often choose Mondays, if I have a choice, as we often have a smaller crew and getting access to the various parts of the telescope is easier. There are fewer people trying to do fewer things at once. Monday turned out to be very good choice indeed, the first clear day at the summit since Christmas. We arrived at the summit to deep blue skies over a landscape of white. Poli’ahu has again blessed the summit of the White Mountain with deep snow.

Snow Day
Looking across at the Keck 1 dome from the top of Keck 2 with Mauna Loa in the background
A small crew does have a disadvantage as well, the chance of being drafted into whatever job needs being done. Not that I was unwilling, the job in this case was clearing snow and ice from the domes. This meant climbing to the top, one place in the facility I had not yet had a chance to go.

So after rigging myself in full safety harness I climbed the dome with the crew. The view from the top is stunning! A full 360 degree view of the summit on a perfectly clear sunny day. The entire summit is blanketed in a beautiful white coat of snow, one of the most dramatic scenes I have ever witnessed. The small Canon G9 camera fit in a breast pocket, small enough not to interfere. I began filling my memory card with many images of the view from the top, reveling in the spectacular vista.

Shoveling Snow
Mike Dahler clearing snow from the edge of the Keck 2 shutter
Not that it was all sightseeing, there was work to do, shoveling snow and chipping ice from the areas where it could interfere with operation of the telescope. Ice and snow coated the upper sections of the dome. Several inches of ice needed to be hammered free of the steelwork and drifts of snow, up to two meters (six feet) deep were packed into any corner and along the side of the shutter. Blocks of ice and shovelfuls of snow flew, crashing to the ground 30m (100ft) below. A crew worked each side of both domes for several hours to complete the task, made all that more difficult by the extreme altitude.

In the thin air there is only so much you can do before you are short of breath. Put down the shovel for a few moments and take a few more pictures. I have material from which to assemble a full panorama as well as dozens of individual images.

After much of the snow and ice had been cleared by hand there was one more step to accomplish. Clear the large drift of snow from the back of the shutter by using the shutter itself as a snowplow. This drift is many tons of snow, over 2m (6ft) thick at the top and about 12m (40ft) wide. When it came down it becomes an artificial avalanche, with huge blocks of snow falling to the ground far below.

Avalanche from Andrew Cooper on Vimeo.

The Symmetry of Mountain Shadows

The sunset view from the summit of Mauna Kea is truly spectacular. From the summit you are usually above the clouds, watching the sun sink into a cloud layer thousands of feet below. The colors are intense, the deep blue sky, the red cinder and the gleaming telescope domes. This spectacle draws tourists from across the globe, trekking up the mountain just in time to witness sunset.

The Shadow of Mauna Kea
The shadow of Mauna Kea rising through the haze at sunset with the pink of the Belt of Venus above
One part of this spectacle is the enigmatic shadow that rises through the eastern haze, a beautiful pyramid of darkness that stretches to the distant horizon. A serene and yet awesome sight, the shadow reaches for infinity through the pastel shades of the Belt of Venus above the blue-grey shadow of the Earth itself. The shape is a perfect pyramid, with a symmetry not expected in a natural phenomena.

Oddly enough, it seems that the actual shape of the mountain is not that important in the creation of such a triangular shadow. The shadow will show that beautiful shape regardless of the mountain’s profile. Even a flat topped mountain will have a shadow that converges to a point at the top. This contradicts our experience, where common shadows match the shape of the casting object. We expect a shadow to portray the object.

A mountain shadow is different, the shadow is elongated to a great distance by the scales involved, in this situation the geometry dictates a different result. The secret to the shape of the shadow is that it is driven by the effects of perspective, with the shadow reaching to a vanishing point in the far distance. In 1979 the problem of the mountain shadow shape was mathematically modeled by William Livingston and David Lynch. They showed that regardless of the mountain’s profile a conical shadow would be perceived by a viewer near the summit. The proportions may differ depending on the profile of the mountain, but the conical shape would remain.

In the case of Mauna Kea, the effect is not obvious, the mountain does have a fairly symmetrical shape with steep sides. A viewer might not recognize the fact that the projected shadow does not match the shape of the volcano. An astute observer may notice a discrepancy, Mauna Kea is notably rounded at the summit, yet the shadow possesses a sharp apex.

I was completely unaware of this until it was pointed out to me a few days ago by Dean Ketelsen when I posted the Mauna Kea mountain shadow image. I suspect Dean has had many opportunities to see this phenomena from atop Kitt Peak, a flat topped mountain that casts a conical shadow.

Two Moonrises

I enjoyed moonrise tonight on the way home, and then enjoyed it again. The first was just after leaving Waimea, a golden full Moon rose over a band of clouds, a beautiful sight as I drove home from work. My drive then takes me deep into the shadow of Mauna Kea, the Moon disappearing behind the bulk of the mountain. A second moonrise found me about ten miles further down the road, with that golden orb rising over the summit. Two beautiful moonrises to grace the end of a long day.

Venus was visible in the golden glow of sunset, mercury right below if you knew to look for it. I saw no sign of Saturn which should have been a ways below the other two, it was probably hidden by a band of clouds that occupied the right spot.

Yes, I did say I was driving home from work on a Saturday. One of the guys on the crew is out with a bad back, and I worked a couple more days on the summit to cover. I was performing some procedures I had never done before, optical alignments in preparation for using the interferometer that night. As a result I will have spent five out of seven days on the summit, quite a bit more than my usual two days a week. I get a day off tomorrow, then back at it Monday. Even tomorrow will not be completely a day off, with an interferometer run in progress there will be some work I need to do from home to check the systems and insure they are ready for the night.

Hopefully the phone stays silent through the night.

Turkey Strike!

There are many hazards in driving the legendary Saddle Road… bad pavement, regular fog, blind curves and hills, one lane bridges, and do not forget the low flying turkeys.

It came out of nowhere, coming across the road at the very worst time as we rounded a sharp curve with no chance to take evasive action before it struck. My wife saw it first, giving that peculiar short half scream I have long ago associated with impending disaster. We were lucky and it didn’t come through the windscreen as it very well might have. A full grown turkey is a big bird, I suspect large enough to smash right through the safety glass and into the face of the driver and passenger. Instead it struck the pillar on the driver’s side and my side view mirror.

Other that my wife’s shocked nerves the only damage is a completely smashed side view mirror and a dent in the molding. What damage the turkey suffered is unknown as it disappeared, apparently still mobile and able to flee the scene of the accident.

So I will be spending a little time on the phone, calling around to junkyards to see if anyone has a side view mirror for a Ford Explorer and reminding myself it could have been much worse.

Turkey Strike
Damage to the side view mirror resulting from a turkey collision on Saddle Road, 30 May 2008

Of Lava Flows and Lunar Eclipses

A good lunar eclipse high in the sky. This was something I have not seen for a while. I have seen several lunar eclipses over the last few years. But they always seemed to be low in the sky from Tucson, rising with the eclipse already in progress. Thus as the date of this eclipse approached I was planning to view it properly. The eclipse would be high in Hawaiian sky, transiting with the Moon in totality. Perfectly placed to view the entire eclipse under the most ideal conditions.

Eclipse Revelry
Everyone at the VIS was enjoying the night!
The timing was highly convenient as I was scheduled to be on the mountain in any case that evening to help prepare for an interferometer run that night. Simply pack the telescope in my vehicle and drive to Hale Pohaku at the beginning of the day so it is waiting with what I need that evening. The scope I chose was my 90mm APO, the focal length was appropriate to frame the Moon well on the Canon 20Da camera. This I mounted on the Losmandy G-11 mount quickly polar aligned with the polar scope and set to track at lunar rate. This particular setup had not been tested together and I thought it would work. I was pleasantly surprised when everything not only worked, but worked quite well.

There was quite the crowd gathered at the Mauna Kea VIS. No surprise, the VIS is the best place on the island to view anything astronomical. Above the clouds and tropical haze the side of Mauna Kea offers a clear view of pristine skies and several telescopes available for anyone to look through. What was surprising was the weather, while the skies are usually clear the VIS can be very cold, and if you add wind the conditions can be miserable. This was not the case! It was cool but not cold and there was no wind beyond a slight breeze.

Eclipse Observing
How to properly observe an eclipse, set the camera on automatic and sit back and enjoy!
We had a couple busloads of high school students, quite a few local folks who knew where to go for an eclipse and the usual group of tourists. The atmosphere was rather festive, a couple musical instruments had appeared and everyone enjoyed the night as the moon slid out of the light.

The proper way to watch the several hours of a lunar eclipse is in comfort. Thinking ahead I brought a lounge chair and setup properly where I could monitor the camera and see the frames on the LCD screen as they came in. This worked perfectly. I could view each frame as it was taken without getting up and adjust settings on the camera simply by reaching over. Between each frame just lay back and enjoy the view.

Well, maybe I am understating the amount of work, things were not that relaxed and the camera took a fair amount of tending. I could not get the camera to autoexpose well with a single bright object in an otherwise black frame. The camera insisted on overexposing the Moon badly, even with automatic bracketing the situation did not work until I just put the camera in manual and adjusted the exposure regularly. The scope did not track perfectly and I did need to adjust the position a few times each hour. But the setup and tending were worth it as the resulting pictures are quite satisfying.

Lava flow from the MKVIS
Lava flowing from the July 21 vent of Kilauea as seen from the Mauna Kea VIS about 30 miles away, taken with the TV-76
This eclipse was darker than any I have seen lately, the Moon dimly seen high in the sky, my camera exposures running to 30 seconds to get a decent image. Once the view of totality had worn off it’s novelty the other telescopes began taking advantage of the truly dark conditions to show deep sky wonders to the crowd. The scopes jumped from Galaxy to globular clusters with the view being fully as good as a moonless night. It seemed of to be looking at M31 and other deep sky objects with the unaided eye on a night of a full moon.

As the eclipse wound down word of another spectacle made its way to me, the glow of something odd seen to the south. This got me out of my comfortable chair to go and see. Surprisingly the usual solid clouds on the east side of the island had parted and the brilliant golden glow of fluid lava was to be seen! There was some confusion as to what it was, some thought it was the lights of Hilo, but there was no confusion to those of us familiar with the view from Hale Pohaku.

The latest lava flow from a rift on the eastern flank of Kilauea was a river 100m wide and several miles long, even from our vantage point thirty miles away we could clearly see the stream. We could see the lava falls near the head of this river with binoculars as well as most of the course. The view of an eruption and an eclipse was and extraordinary reminder of the dynamism of the earth and universe around us.

Above is one of my photos from mid-totality taken with the 90mm APO and a Canon 20Da DSLR, note that several stars frame the moon. Check out a few more pictures of the eclipse from the visitor center by Simona Vaduvescu

Lunar Eclipse 28Aug2007
Total lunar eclipse, photo is a 8sec exposure with a Canon 20Da on a 90mm f/12 APO