Comet Lovejoy in the Daylight

I did attempt to see comet C/2011 W3 Lovejoy in the daylight. I actually tried several times. Once on the morning of the 15th and a couple more times on the morning of the 16th after I heard that the comet had survived perihelion passage. Neither time did I see the comet with an unaided eye.

On the 15th I was not surprised I could not see it. I was in Waimea where there was a lot of low altitude haze and a lot of glare around the Sun. On the 16th I had a much better chance using the clean high altitude air of the summit of Mauna Kea. But still, no comet seen even though it should be just over four degrees from the Sun. This is about the same separation that had allowed me to see comet McNaught in early 2007.

Just to be certain I set the camera on a tripod, placed it just inside the shadow of the Keck 1 dome, and blazed away. Examining the photos on the camera display likewise revealed no trace of the comet, but there were some interesting spots of light.

It was not until I sat down and really analyzed the raw frames that I found something. Using some astronomy software, I calculated the position of the comet when the shots were taken and the field of view of the camera. And lo! There it was, a small spot with a trace of tail. It showed up best in the green channel, and not at all in the blue thanks to Rayleigh scattering in our atmosphere. Stacking nine of ten frames and processing the heck out of the frames does allow you to clearly see the comet…

Comet C/2011 W3 Lovejoy
Comet C/2011 W3 Lovejoy photographed 4° from the Sun on at 19:47UT on the morning of 16Dec2011. Canon 60D and an 85mm lens, stack of nine frames, green channel only.

Postcard from the Reef – Caving

the Kona Coast is riddled with caves, old lava tubes, wave carved openings in ancient sea cliffs, or simple small openings in the coral. The caves are high on many diver’s priority lists when exploring the reef. In these caves you find many species that hide during the light of day, lobsters and night active fish. The larger caves offer a sheltered environment, safe from the pounding winter surf. The walls are covered with colorful sponges and the nudibranchs that feed on them.

If there is a cave, you will probably note my fins disappearing into it.

Caving
Olivier Martin exploring a cave at O’oma

Daytime Comet Reminder

Will Comet C/2011 W3 Lovejoy be visible in the daytime? This is the morning to find out. Look about 2° below the rising Sun once it is well up in the clear sky for a small white object. Two degrees is four times the Sun’s width in the sky.

C2006/P1 McNaught
C2006/P1 McNaught photographed five degrees from the Sun, stack of three images
If the comet is not visible to the eye, it should be spectacularly visible in the imagery sent back by one of our solar monitoring satellites. Check out the SOHO page for the latest imagery. The comet should have entered the field of view of the LASCO C3 instrument early on Dec 14th (late on the 13th HST) and well in by the time this posts. If the comet does not survive perihelion passage, this is one of the best views of the event.

I have seen one other daytime comet in my life, C2006/P1 McNaught back in January of 2007. That time the comet was about 5° from the Sun, over twice as far away from the glare. The photo at the right should give an idea of what to look for today. Remember to shield your eyes from the Sun’s glare by positioning yourself to put the Sun behind some object like a wall or streetlight. There is no guarantee that Lovejoy will be at all visible, but it is worth taking a look this morning.

Geminids

The annual Geminid meteor shower has become one of the most reliable annual meteor showers. First observed over 150 years ago this is a interesting meteor shower. The parent body for the Geminids is not a comet, but rather the asteroid 3200 Phaethon. It is somewhat of a mystery how this mostly rocky body gives rise to the debris stream needed to generate a meteor shower.

The evening of Dec 14th into the morning of Dec 15th is favored, starting around 8pm as Gemini rises in the east.

While the 2011 Geminids are expected to just as numerous as usual, viewing will be hampered by a bright Moon in the sky. Certainly the brighter fireballs will be easily visible, but the dim meteors will be lost to the moonlight. If you do wish to try your luck, view between midnight and dawn on the night of the 14th and into the morning of December 15th. It may be possible to see some meteors after the radiant rises, about 8pm, and before moonrise around 10pm on the evening of the 14th.

Watching meteors requires no more equipment than your eyes and a dark sky, and can be enjoyable for just about anyone. Set the alarm clock, this one should be worth the early morning wake-up.

A Missed Eclipse

Plans for a summit run and some lunar eclipse photography. A midnight alarm clock and departure for the summit was the strategy. I planned to shoot time lapse of the eclipse setting over the Keck telescopes. But the best laid plans sometimes hit a snag…

I had noticed some minor power loss and roughness in the engine heading into work. Some condensation in the system? Perhaps just some bad gas? It was on the way home that the trouble became truly clear. A rhythmic stutter accompanied by a more severe power loss. As I limped home listening to the engine I realized that at least one cylinder of the six was not firing. A faint smell of gas when I got out of the vehicle just seemed to confirm the hypothesis.

That evening I spent a bit poking at the engine, inspecting for a loose connection or some other easy cause. I removed and cleaned the mass air sensor, a known trouble spot. Checked the air intake and ignition system. Removed battery power to allow the electronic engine controls a full reset to default settings. Still, when I started it up there was that rhythmic stutter.

Lunar Eclipse 20070828
Total lunar eclipse of 28 Aug 2007, photo is a 8sec exposure with a Canon 20Da on a 90mm f/12 APO
I was not going eclipse chasing this night. No way was a partially crippled vehicle going to make it to the summit of a 14,000ft mountain.

Instead I simply set the alarm clock for a bit before totality and watched the eclipse from my front lanai. I made no attempt at photography, I do have quite a few decent eclipse photos. Instead I simply watched as the Moon ghosted through a thin layer of clouds. It was quite pretty, a bright Orion and Gemini were visible through an opening for a while. Much of mid totality was lost to the clouds, but it opened up again at the end allowing a nice view of the first touch of direct sunlight on the Moon.

As for the vehicle? I still was not certain what was the issue. This could be the result of something truly serious considering the engine has well over 180,000 miles on it. Plans for a replacement vehicle are under consideration, but I love this old truck. The first new vehicle I had ever owned, a veteran of hot dusty Arizona mining roads, of icy mountain passes, of rocky Hawaiian coastlines carrying scuba gear in the back. How many times has this vehicle waited through the night, telescope setup beside it, while I explored the sky from some remote and dark campsite? A trusted steed that has carried me to so many great places and always gotten me home.

The maintenance manual has a list of a dozen things that can cause misfires. May as well start with the easy (and cheap) stuff. I drove Deb’s car into Waimea to run a few errands and pick up a set of ignition cables and spark plugs.

Damaged Spark Plug Cable
A damaged spark plug cable shows why.
It was the first cable I removed the revealed the trouble, a bad break in the cable where it had rubbed against a mounting bracket for the fuel line. Arced and blackened it was clear that my hunch was correct. A sense of relief, perhaps it was something this simple. I won’t know until I finish the job of replacing all six cables and plugs.

That would be almost two hours later, two hours of cursing the engine designers who would obviously not ever have to replace the plugs on this engine. Who puts a hard fuel line right in line with the spark plugs? I go back to the toolbox for the 3/8″ universal joint and spend a few minutes figuring out what combination of extensions will get me through which gap in the hoses and lines. Really? Is cylinder three’s plug under there? I will have to do it entirely by feel.

Finally! All plugs in place, cables neatly routed around the block, tools picked up from around the engine compartment, I have a chance to turn her over. A quick crank and she starts, idling with a smooth purr that is simply music to my ears. My old friend will be with me for a little longer.

This was the last total lunar eclipse for the next three years. I did watch it, remembering other total lunar eclipses across the years. An eclipse seen from among a stand of saguaro cacti in the Arizona desert, another eclipse watched from the Mauna Kea VIS just a couple years ago. A copper moon high over the broken walls and ruins of a 12th century priory. This eclipse will mark yet another memory, to be recalled when I again sit under a blood red Moon in the middle of the night.

Postcard from the Reef – Hawaiian Spiky Sea Cucumber

These sea cucumbers are well known to divers and can be found in the local guide books. There is no scientific name, the species has never been properly described. An odd state of affairs for a relatively common critter. As for the name? I could come up with a few other common names that seem to describe the appearance. However, naming a species after a pile of doo-doo is not generally acceptable.

Hawaiian Spiky Sea Cucumber
Hawaiian Spiky Sea Cucumber (Stichopus sp.) at 100ft depth off O’oma, the species is well known but undescribed in the literature

A Daytime Comet?

The rumor is running around the various astronomy sites and listservers that Comet C/2011 W3 Lovejoy might be daytime visible. Will it be? That is a very qualified maybe.

C2006/P1 McNaught
C2006/P1 McNaught photographed five degrees from the Sun, stack of three images
This sun-grazer comet was discovered just a few days ago, on November 27th, by Australian amateur astronomer Terry Lovejoy. The comet is a member of the Kreutz comet family, and like other members of the family it will approach the Sun quite closely, about 548,000 miles (882,000 km) from the Sun. Of course those distances are solar centric distances. Taking the radius of the Sun into account means that the comet will be a mere 115,000 miles (186,000 km) above the photosphere, hot indeed!

It becomes a valid question to ask if comet Lovejoy will even survive perihelion transit.

Passing that close to the Sun will mean that the volatile elements of the comet will be streaming off the comet at a fantastic rate, enough to dramatically brighten the comet. Below you will find the ephemeris for perihelion on Dec 16th (Dec 15th HST) from the Minor Planet Center. As you can note, the predicted magnitude is -8! This is bright enough to be seen in broad daylight. Thus the possibility of a daytime comet.

The catch is that the comet will be quite close to the Sun. Within 2° as the Sun and comet rise on the morning of the 15th here in Hawai’i. For observers in the islands the best chance to look is on the morning of the 15th, as perihelion will occur in the afternoon as the comet passed behind the Sun from our point of view.

Will it be visible? Maybe. It depends on the accuracy of the magnitude estimates, which are uncertain to say the least. It could be substantially dimmer, or even substantially brighter than forecast under such conditions. The proximity to the Sun also complicates the issue. It is worth a look, seeing a daytime comet is highly unusual.

If you do look please take a few simple precautions… Do NOT use any sort of optical aid this close to the Sun, the risk of permanent eye damage is too great. If it is bright enough the comet should be a naked eye object. It will greatly help to position yourself to put the Sun just behind some obstruction. A building, a streetlight, anything to block the Sun’s glare and aid in picking out the comet. On the morning of the 15th the comet will rise 2° behind the Sun, thus 2° lower in the sky.

Give it a try!

Green Flash

It was a beautiful evening as I drove home from work. The clear air allowing appreciation of all five volcanoes that loom over South Kohala. Indeed, the horizon was completely clear, the island of Kahoʻolwe visible over 60 miles away.

As I drove I noted the Sun beginning to settle into the distant horizon. At the wheel I couldn’t look long enough to be certain, but I thought I saw an Etruscan vase effect as the solar disk made first contact with the horizon. Curiosity peaked, I pulled over to properly watch the end of sunset. A pleasant surprise rewarded my view, a decent green flash was apparent as the last glimmer vanished.

Better yet, the camera caught the effect as well. Of the dozens of sunsets I have stopped and watched, this was the best green flash seen yet from such a high elevation. Still, it was modest compared to a couple flashes I have seen from sea level. I can only wonder how good this evening’s flash was as seen from the shoreline, 2,000 feet below.

Green Flash
A modest green flash as seen from the Mamalahoa Highway outside Waimea, 1 Dec 2011

Postcard from the Summit – Colorful Commute

As winter descends on Mauna Kea, commuting to and from the summit had become… interesting. Fog, snow and ice being regular features of the drive. Winter weather has also brought fantastic cloud formations, all the more interesting as you drive into them. The later dawn and earlier sunset means that our usual arrival and departure times are filled with dramatic light. All elements become part of a spectacular show.

Colorful Commute
Shane, a Mauna Kea Ranger, heading down the mountain into a rainbow