Faintest Early-Universe Galaxy Ever, Detected and Confirmed

W. M. Keck Observatory press release

An international team of scientists has detected and confirmed the faintest early-Universe galaxy ever using the W. M. Keck Observatory on the summit on Maunakea, Hawaii. In addition to using the world’s most powerful telescope, the team relied on gravitational lensing to see the incredibly faint object born just after the Big Bang. The results are being published in The Astrophysical Journal Letters today.

MACS2129.4-0741
Color image of the cluster taken with Hubble Space Telescope (images in three different filters were combined to make an RGB image). Credit: Bradac/HST/W. M. Keck Observatory
The team detected the galaxy as it was 13 billion years ago, or when the Universe was a toddler on a cosmic time scale.

The detection was made using the DEIMOS instrument fitted on the ten-meter Keck II telescope, and was made possible through a phenomenon predicted by Einstein in which an object is magnified by the gravity of another object that is between it and the viewer. In this case, the detected galaxy was behind the galaxy cluster MACS2129.4-0741, which is massive enough to create three different images of the object.

“Keck Observatory’s telescopes are simply the best in the world for this work,” said Marusa Bradac, a proefssor at University of California, Davis who led the team. “Their power, paired with the gravitational force of a massive cluster of galaxies, allows us to truly see where no human has seen before.”

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Dual Lasers on the Galactic Center

I have been trying to get some good photos of both Keck lasers on the galactic center for some years. Other photographers have produced spectacular photos that have me seething with envy. Why can I not get equivalent photos? It is not like I have a lack of access. The answer is mostly bad luck and circumstance. I do work, this limits the nights I can make the attempt. On those times I have ascended the mountain to photograph I have been plagued by bad weather.

Dual Lasers on the Galactic Center
Both Keck lasers aimed at the center of the Milky Way galaxy
There are only a few nights a year when Andrea Ghez and the UCLA Galactic Center Group have both telescopes scheduled, the night when both lasers will be focused on the core of our galaxy and the massive black hole that dwells there. Last year I had attempted a night only to find clouds and fog through the night allowing only a few moments of dual lasers and disappointing results.

This year looked to be much the same. The night was set, I had volunteered to host several local photographers, we had film permits on-hand, an observatory vehicle reserved, all the arrangements made. The only issue? The Mauna Kea Weather Center forecast promised high clouds and fog for the night. I was bracing for yet another disappointment.

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Metal Content in Early Galaxies Challenges Star Forming Theory

W. M. Keck Observatory press release

An International team led by scientists at ETH Zurich in Switzerland used the W. M. Keck Observatory to study the role of star formation rates in metal contents of distant galaxies. What they discovered is the amount of metals are very similar, irrespective of galaxies’ star formation activity, raising new questions about star-forming theory. Their findings were recently published in the Astrophysical Journal.

Heavy Elements
A galaxy observed in this study (surrounded by a blue rectangle). The light we received from the galaxy in the distant Universe tells us – from hydrogen, oxygen, and neon emission lines – that they followed a different rule to produce the heavy elements. Credit: 3D-HST / NASA / ESA / STSCI
Using the MOSFIRE instrument installed on the Keck I telescope – one of the two world’s largest optical telescopes at Keck Observatory – the scientists gathered data on 41 normal, star-forming galaxies that were 11 billion light years away.

The team found typical galaxies forming stars in the Universe two billion years after the Big Bang have only twenty percent of metals (elements heavier than Helium) compared with those in the present day Universe. They also discovered the metal content is independent of the strength of the star-formation activity – in stark contrast with what is known for recently formed, or nearby galaxies.

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Four Synchronized Planets Reveal Clues to How Planets Form

W. M. Keck Observatory press release

The search for planets orbiting other stars in our galaxy has revealed an extraordinary family of planets whose orbits are so carefully timed that they provide long-term stability for their planetary system. The data came from observations from the Kepler Space Telescope and the W. M. Keck Observatory on Maunakea, Hawaii. A paper describing the formation of this planetary system by a research team was published in the journal Nature today.

Kepler223 Animation
The Kepler–223 planetary system, click on the image for an animation. Credit: W. Rebel
“The Kepler-223 planetary system has unusually long-term stability because its four planets interact gravitationally to keep the beat of a carefully choreographed dance as they orbit their host star,” said Eric Ford, a professor of astronomy and astrophysics at Penn State and a member of the research team. Each time the innermost planet (Kepler-223b) orbits the system’s star 3 times, the second-closest planet (Kepler-223c) orbits precisely 4 times. Thus, these two planets return to the same positions relative to each other and their host star.

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Mercury Transit

It was a beautiful morning! Alarm set for 4:30am, out of the house at 5am, setup just at sunrise on the old Saddle Road. The sun rose through low clouds over the grasslands of Parker Ranch with Waimea to one side and Mauna Kea on the other.

Mercury Transit 9May2016
Mercury transiting the Sun on May 9, 2016. Celestron C8 and Canon 6D at f/10.
Setting up a telescope as the Sun was rising seemed just wrong. I am used to breaking down a telescope as the Sun comes over the horizon at the end of a night’s observing. It is not often that an observing session results in my risking sunburn!

The seeing was pretty horrible at sunrise but rapidly improved as the Sun rose. As the transit ended the seeing was quite sharp and the photos not all that bad. At least as long as I kept the shutter speeds high. Visually the view was quite nice, a sharp black dot against the Sun, a far cry from the dancing blur you usually see when trying to view Mercury in the glow of Sunset.

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Mercury Transit Reminder

Just a quick reminder that mercury will transit the face of the Sun tomorrow morning. You can read full details in my earlier post or check out a decent transit calculator. For observer in Hawaii the transit will already be well underway at sunrise, making this a set-the-alarm-early exercise. My telescope and solar filter are already loaded… Are yours?

Transit of Mercury
The 2006 transit of Mercury, photographed with a 90mm telescope and a Canon 20Da

Moon in the Hyades

This evening a pretty crescent Moon will pass through the bright Hyades star cluster. The Moon will be a very thin crescent, only 2.9% illuminated and 1.5 days past new. As such it will not be so bright as to completely over power the star cluster. The Moon will be 3° west of the bright red star Aldebaran, at the center of the vee shaped cluster. As the cluster is 15° above the horizon at sunset there should be ample time to enjoy the sight before the Moon sets at 20:12 HST.