Tag: Keck

Aussie Scientist Finds Rare Supernova at Keck Observatory

W. M. Keck Observatory press release by Dr. Duncan Forbes…

It was a dark and stormy night in the city of Angels. Well, actually it wasn’t. But more on that later…

It was a clear night on the summit of Mauna Kea at Keck Observatory on the 20th March. My colleagues and I were using the Echellette Spectrograph and Imager (ESI) instrument, which looks at faint objects in the visible wavelengths, to study star clusters and small galaxies.

SN2014ai
Can you spot the supernova? Supernova SN2014ai on March 20th, 2014
I was actually in our special ‘remote ops’ room at Swinburne University, with my postdoc, Joachim Janz. This is a room decked out with a computer, a backup computer, a video-link to Keck Observatory and a dedicated Internet connection. As we are 21 hours ahead of Hawaii, it was a Friday afternoon when we started observing that Thursday night. My colleagues Sam Penny and Mark Norris were in the Keck control room, and Aaron Romanowsky was in his remote ops room at UC Santa Cruz.

Shortly into our night’s observing, we noticed a bright source in the guide camera image that wasn’t on our finding chart of that region. Still we managed to find our target and took a spectrum of it. But we decided to go back and see if that `new’ bright source was still there. Sure enough it was and it hadn’t moved. It was probably a supernova (or an asteroid coming straight at us!), so I decided to get a 5min spectrum with ESI. And indeed we had found a supernova—a type Ia to be exact. Type Ia supernovae are fairly rare in the nearby Universe and represent the explosion of at least one white dwarf star in a binary system. It is this same type of supernova that led to the discovery of Dark Energy in the Universe using the Keck Observatory, and three Nobel prizes.

Our supernova is located in the outskirts of a galaxy some 100 million light years from us—so it exploded 100 million years ago but the light only reached us that night.

I later found out that an automated telescope on the Palomar Mountain overlooking Los Angeles detected the supernova shortly before us. They also managed to get a spectrum but that was taken after our Keck II/ESI spectrum. The exciting thing is that both the Palomar Observatory and ourselves managed to observe the supernova in the 1-2 weeks before it reaches its maximum brightness (and then fades steadily after that).

The supernova has been given the designation SN2014ai.

All in all, not bad for a late night at the office…

Duncan Forbes is a professor of astronomy at Swinburne University in Melbourne, Australia, and a 2014 Evenings with Astronomers presenter at the signature Friends of Keck lecture series. Swinburne astronomers are awarded time for their research on Keck Observatory through an agreement with the California Institute of Technology.

Snow Day

It was a snow day at the summit. We arrived to a new layer of snow atop the snow that had been accumulating all weekend, about 8 inches in total. It continued to snow much of the day, sometimes heavy. By the time we left the total was closer to a foot of white atop the mountain.

Instructions from summit lead were clear, start nothing we could not put away in a few moments in case the decision to abandon the summit was made. Despite this I did get some productive things done… Fixed the K1 Laser Safety System, an easy fix, helped perform a maintenance check on the MOSFIRE rotator, and arranged some fabrication for a camera mount in the K1 dome.

John made the call to leave the summit just before 3pm, as conditions began to worsen and the temperature started falling again. Observing was officially cancelled about the same time, the nighttime operators would not attempt to make the summit. An interesting day. What will we find tomorrow?

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Distant Asteroid Revealed to be a Complex Mini World

W. M. Keck Observatory press release…

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.

624 Hektor NIRC2
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/Marchis
This 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).

Continue reading “Distant Asteroid Revealed to be a Complex Mini World”

Water Vapor Detected in the Atmosphere of a Hot Jupiter

W. M. Keck Observatory press release…

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.

Exoplanet Water Spectra
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.

Continue reading “Water Vapor Detected in the Atmosphere of a Hot Jupiter”

A Lecture and a Star Party

If you did not make a point to come to the last Keck lecture you missed a fun night.

Greg Doppmann
Keck astronomer Greg Doppmann lecturing on the spectra of planet forming disks
Our regular free lecture featured one of Keck’s own this month. Greg Doppmann gave a very informative talk on using one of the Keck spectrographs, NIRSPEC, to examine the inner planet forming disks around young stars. In the near infrared it is possible to determine the presence of water and organic compounds in the material that rocky world may form from.

Greg did a very nice job of explaining spectroscopy. this is never easy, the details can get pretty technical. Making sense of spectra while talking to a general audience is a neat accomplishment. This is even worse when you are talking about the spectra of water in the near infrared where there are thousands of emission lines. Good graphics and a step by step explanation worked, animations of dancing water molecules, and dancing Greg not withstanding.

Waiting for Tony
Tony with a large line of folks waiting to see Jupiter in his 12″ ‘scope
After the lecture everyone was able to enjoy great views of the Moon and Jupiter through telescopes set up by our astronomy club. We got lucky, the notoriously fickle Waimea weather gave us a break. At the start of the lecture is was raining, not hard, just the usual Waimea mist. As Greg’s lecture wound down I ducked outside to be greeted by a bright Moon and no clouds. Somewhat stunned I hurried back inside to give the thumbs up to the crew, who scrambled to setup the ‘scopes before the Q&A session ended.

When the crowd poured out we were ready. A lot of folks stayed to view, and five ‘scopes were in operation to meet them. I have to give thanks to Tony, Chris, Rickey, Cliff, Bernt, and Purcynth, who manned the scopes and answered the flood of questions. As we were breaking down the clouds were rolling back in, very good timing indeed.

The lecture was recorded and should show up on the Keck website soon. I’ll try to post a link to it when it does appear. In the meantime, if you have not already done so, get your email on the Keck Nation list so you know about these events before they happen.

Seven Years on the Mountain

Numerologists love the number seven. Another odd number that has come to have a special meaning for no real reason.

First Target of the Night
The Keck 2 AO Laser attempting the first target of the night with the light of sunset and a setting Moon behind
I have been working atop Mauna Kea for seven years now. This place that once seemed so alien is now so familiar. I walk through the observatory and look about, noting all of the things I have worked on, installed, or been involved with in some way. There are few parts of the facility I have not touched.

I helped install much of the Keck 1 laser system, from running the cables to aligning the launch telescope. The weather monitoring system atop the roof and in the domes is all my work, a complete replacement of the system over the last few years.

Secondary Selfie
A self shot looking into the Keck 2 secondary, at a reflection of the primary.
It is the AO systems I have been most involved with, responsible for the day-to-day functionality of the hardware. Entering an AO enclosure so many memories stream about. There is little I have not had to repair or work on in some capacity. I am familiar with every cable, every button and switch. I can recall schematics of many of the devices, the documents that show where everything is interconnected, I have drawn or edited most of them. I have had my small part in every discovery that comes from these amazing systems.

Mauna Kea Shadow
The shadow of Mauna Kea appears through the mist and haze at sunrise
I recall nights with both lasers stabbing the sky, golden beams amongst the bright stars. There have been glorious sunsets, of foggy sunsets when the world turned golden. There have been days we have dug our way into the building through drifts of snow, coatings of ice on every surface with foot long sideways icicles. Of driving through drifts of snow, tire chains scraping the ice, with snow flying and the vehicle skidding towards the guardrail. Of winds so strong they threatened to overturn the vehicles as we scramble to abandon the summit. I have watched the dawn after a long night of observing, the Sun rising above billowing clouds, the first brilliant rays etched into my memories.

Mauna Kea is a place of wonder and beauty that I have been privileged to experience, a treasure of memories to enjoy for a lifetime.