After 8 years of observations scientists from the SETI Institute have found an exotic orbit for the largest Trojan asteroid, (624) Hektor—the only one known to possess a moon. The formation of this system made of a dual primary and a small moon is still a mystery, but they found the asteroid could be a captured Kuiper body product of the reshuffling of giant planets in our solar system. The results are being published today in Astrophysical Journal Letters.
Two adaptive optics observations made in July 2006 and October 2008 with the Keck II telescope. The center of each image shows the elongated shape of Hektor. The small, faint moon is shown in the cyan circle. Credit WMKO/MarchisThis study, based on W. M. Keck Observatory data and photometric observations from telescopes throughout the world, suggests that the asteroid and its moon are products of the collision of two icy asteroids. This work sheds light on the complex youth of our solar system, when the building blocks that formed the core of giant planets and their satellites were tossed around or captured during the giant planet migrations.
In 2006, a small team of astronomers led by Franck Marchis, astronomer at the Carl Sagan center of the SETI Institute, detected the presence of a small 12 km diameter moon around the large Trojan asteroid (624) Hektor. They used the 10 m Keck II telescope atop Mauna Kea, fitted with the NIRC-2 (the Near-Infrared Camera 2) instrument behind the adaptive optics and laser guide star system (LGS-AO).
The corral is one of the relics of ranching that litter the Waimea countryside. Just a short detour off my daily commute, I have long noted the photo potential of the place. A foggy day offered an interesting opportunity to shoot the corral, enough that I missed my usual turn to take advantage of the even, subdued light offered by a grey afternoon.
Arriving I noted that recent rains had transformed the brown grass into a verdant green. Vines had appeared to cover the old fence posts in foliage. This was a good day to go shooting.
Photography is an art that has to be constantly practiced. You need to shoot, shoot some more, and critique the results with a stern eye. I have better gear than I have ever had, it helps. Still, the magic is up to the photographer, not the camera. A practiced eye, composition and creativity, any camera can shoot a great photo in the right hands.
I did get some good shots. But did I get any great shots? I am always my own worst critic.
An old corral falls into ruin south of Waimea
Recent rains have turned the brown land to verdant green
Old wood and wire, patched and modified for generations
The wear of many seasons of work scar the wood, rust betrays the lack of use
Vines now keep this old gate permanently shut, Canon 6D and 24-105mm f/4 L lens
Tomorrow morning, Feb 27th, the planet Mercury can be seen about 3° below the rising Moon. Mercury will rise about 05:29HST and be over 15° above the horizon at sunrise. The Moon will be quite old, a very thin 4% illuminated crescent. the pairing should make for a pretty dawn.
California Institute of Technology (Caltech) astronomers using data gathered at the W. M. Keck Observatory have developed a new technique for planetary scientists that could provide insight into how many water planets like Earth exist within our universe. The results have been published on February 24th by The Astrophysical Journal Letters.
Simulated data showing the method used for detecting water vapor features detected around the hot Jupiter tau Boo b. Credit: Alexandra Lockwood (CalTech) background image used with permission from David Aguilar (CFA)Scientists have detected water vapor on other planets in the past, but these detections could only take place under very specific circumstances, according to graduate student Alexandra Lockwood, the first author of the study. “When a planet transits, or passes in orbit, in front of its host star, we can use information from this event to detect water vapor and other atmospheric compounds. Alternatively, if the planet is sufficiently far away from its host star, we can also learn about a planet’s atmosphere by imaging it.”
However, a significant portion of the population of extrasolar planets does not fit either of these criteria and there wasn’t really a way to find information about the atmospheres of these planets. Looking to resolve this problem, Lockwood and her advisor Geoffrey Blake—Caltech professor of cosmochemistry, planetary sciences and chemistry—were inspired by the recent detection of carbon monoxide in the extrasolar planet, tau Boo b and they wondered if they could detect water in a similar manner.
Venus approaching inferior conjunction, 24Dec2013Tomorrow morning, February 24th, will see a brilliant Venus paired with a crescent Moon. Look for the pair to rise about 04:00HST to be 33° above the horizon at sunrise. An 18% illuminated Moon will be a nice match for Venus shining brilliantly at -4.6 magnitude. Separation will be about 7°.
The following morning, February 25th, will see the Moon 7° below Venus. Observant sky-watchers will note Mercury another 16° closer to the eastern horizon and the rising Sun.
A result from Saturday night. About an hour of integration all told… Good color, very nice stars, good detail. While encouraging, I really need more time on this one, there is too much noise in the fainter regions of the nebula. I can get more data and add it to the stack to continue to improve the result. From up on the mountain I should be able to use longer exposures with darker skies. Colder conditions will reduce the dark current in the camera, also aiding in longer exposures.
A single unprocessed subframe of the Rosette Nebula, Canon 6D and TV-76mm, 240s @ ISO6400Compare the processed shot with the single subframe I published yesterday. The final shot is a stack of 10 x 4min, 10 x 1min, and 10 x 15s frames, 30 frames for just under an hour of exposure. Also needed is another 10 x 240s dark frames and 10 flat field frames to use for calibration. This takes another hour, but was done after the telescope was rolled back into the garage and I went to bed.
The Rosette Nebula is a large star forming region just east of Orion in the constellation of Monocerus. It is quite large, the main body seen in the photograph is well over a degree across. The dark region in the center is about the size of the Full Moon
The Rosette Nebula, NGC2237, NGC2238, NGC2244, NGC2246, Canon 6D and TV-76mm, 10x240s+10x60s+10x15s @ISO6400
A single unprocessed subframe of the Rosette Nebula, Canon 6D and TV-76mm, 240s @ ISO6400After solving the little equipment issues, waiting out weeks of bad weather and waiting for the Moon to go away, I finally had a nice photographic night. Setting up at sunset I shot until the Moon rose. Most of the targets I have shot before, Orion, Rosette, Markarian’s Chain. I also shot Melotte 111, an object that has always intrigued me. The full frame camera and the TV-76 has a wide enough field to capture this very large and nearby star cluster.
I want to use this combination camera and telescope with a very wide field to work over the dark nebulae of the Summer Milky Way. With 384mm focal length the full frame camera gives me over 5.35° x 3.56° field of view. The beehive also lent itself to the wide field, another large object that was worth a stop to shoot.
Aside from one little equipment issue to start, more an operator education issue, the gear worked great. Note to self… Must turn off camera WiFi before the camera will link to the computer via USB. I am currently using APT to control the camera, a very impressive bit of software. The auto-guider worked perfectly, frame after frame nearly identical. I can slideshow through dozens of sub-frames and not see any difference, no drift!
A single sub-frame of the Rosette Nebula is shown to the right. The Rosette is an emission nebula with most of the light emitted at the wavelength of Hα 656.28 nm. My Canon 6D is stock, no astrophoto modifications. Despite an IR cutoff filter that blocks much of the Hα light the camera captures a fair amount of the nebula. Perhaps I should get a 48mm Hα filter for the camera to shoot from the driveway.
With everything working so well I really need to haul the rig up to Hale Pohaku for a night of imaging under darker skies than I get down at 1000ft. Next weekend is dark-of-the-Moon weekend. Need to plan an outing?
It will take a bit to process the results of the night. As usual, keep an eye here on Darker View for the finished photos.
We found a few of these when hiking in Volcanos NP a couple weeks ago. A little searching revealed some ripe ones. Nice flavor, a little tart, not unlike cranberry they need a little sweetener to make them really good.
ʻŌhelo berry (Vaccinium reticulatum) fruiting on lava flows along Saddle Road
Occasionally I use the Google image search function to see if any of my photos are being used on other websites. Yes… It is something to do when insomnia strikes.
Earlier this month I found quite a few of my photos being used on an very obnoxious site. The same page also contained numerous images from the West Hawai’i Astronomy Club website. I will forgo including the URL or link here, no need providing them one more incoming referral. Suffice it to say that the entire website was constructed of stolen or scraped material, the sole purpose of which is to serve as search engine bait. Once on the website clicking on anything generated pop-ups, pop-unders, a slew of ads. This was not innocent infringement, this is a business built on theft of intellectual property.
A little sleuthing revealed that the site was located on a hosting service out of the Netherlands, WorldStream.nl. As this site is not within the US a DMCA takedown notice is not legally enforceable. However, European law is pretty good with respect to copyright, the hosting provider should take a notice of infringement seriously. Thus I sent an email off to the listed customer service address…
