Small Solar System Found

For years the search for exoplanets has largely been like Gulliver’s visit to Brobdingnag: colossal systems of giant gas planets orbiting mammoth stars. But astronomers have finally landed on the shores of Lilliput. They have found a tiny star with three puny planets, each smaller than Earth, zooming around it.

The three small exoplanets orbit a star called KOI-961. Their radii are calculated to be 78, 73 and 57 percent that of Earth. The sizes of the planets were worked out by Kepler Telescope observations that measured the dimming of the star KOI-961 as each planet passes in front of it. This plus crucial information about the star from Keck and Palomar telescopes enabled researchers to determine the sizes of the planets.

Although the masses of the three planets are unknown, they are suspected of being rocky, like Earth, Venus, Mars and Mercury. But they orbit too close to their star to be in the habitable zone where liquid water could exist. The three planets take less than two days to orbit around KOI-961, which is a red dwarf with a diameter one-sixth that of our sun, making it just 70 percent bigger than Jupiter.

“This is the tiniest solar system found so far,” said John Johnson, the principal investigator of the research from NASA’s Exoplanet Science Institute at the California Institute of Technology in Pasadena. “It’s actually more similar to Jupiter and its moons in scale than any other planetary system. The discovery is further proof of the diversity of planetary systems in our galaxy.”

Continue reading “Small Solar System Found”

Magnitude

Throughout the astronomical descriptions and event posts here on Darker View I use the term magnitude to describe the brightness of an object in the sky. Magnitude is a simple scale, but somewhat confusing without a quick introduction.

The origins of our current magnitude scale are as old as the science of astronomy itself. One of the first stellar catalogs, the Almagest, was compiled by Claudius Ptolemy in the 2nd century. To denote the brightness of stars the catalog assigned the brightest as being “stars of the first rank”, with a corresponding second rand, third rank, etc. The dimmest of stars, the faintest visible to the unaided eye, were assigned to the sixth rank. This system was used with little alteration for the next two millennium. Subsequent catalogs and observers used their own versions of the scale, perhaps adding a decimal place to denote finer differences in brightness. As there was no instrumental method of measuring the brightness, magnitude estimates varied widely from source to source.

With the dawn of modern photographic methods and later electronic methods, it became possible to systematize the scale. It was desirable to create a scale that approximated the old system and time honored traditions. Thus the current magnitude scale was developed, understanding the origins allows understanding of the modern system.

Continue reading “Magnitude”

Employment at Keck – Electronics Engineer

W. M. Keck Observatory position announcement…

The W.M. Keck Observatory seeks an Electronics Engineer to join a multi-disciplinary engineering team that operates, maintains, and improves high-technology systems at the observatory including telescope controls, primary mirror controls, adaptive optics and more. This is a challenging fast-paced technical environment where teamwork, and interpersonal communication are essential skills.

The observatory operates two of the largest and most scientifically productive optical/infrared telescopes in the world. The twin 10-meter telescopes are located amidst several other world class observatories on the summit of Mauna Kea, at 13,796 feet above sea level on the Big Island of Hawaii, one of the premier sites for astronomy. The successful candidate will have the opportunity to join a skilled and deeply committed team of technical professionals who enable exciting and important astronomical discoveries.

Qualifications for this position include a Bachelor of Science degree in Engineering with emphasis in electronics and control systems and five years of work experience designing, building, analyzing, testing and troubleshooting of electronics and electromechanical systems. The ideal candidate will have a strong understanding of analog and digital electronics, real-time PID motion control systems, computer interfaces, noise, shielding and grounding principles, and be well organized and have good documentation skills. Desirable skills include project planning and management, configuration management, and knowledge of electronics and electrical engineering standards. Because of the observatory’s location, a significant amount of time will be spent working at high altitude.

This position requires you to submit your resume on-line at: http://keckobservatory.iapplicants.com/ViewJob-262125.html with your cover letter that states why you are uniquely qualified for the position.

Additional information about WMKO and this position may be found on our website at www.keckobservatory.org EEO/M/F/D/V

Elongations, Conjunctions and Oppositions

As a planet moves across the sky there are particular points in its orbit that describe the motion, part of the jargon of astronomy that can confuse the uninitiated. These terms do not represent anything difficult, you just have to visualize what they mean. Understanding the movements of planets across the sky gives a little insight into our beautiful universe.

Elongation, opposition and conjunctions
Elongation, opposition and conjunctions, the apparent positions of a planet with respect to the Earth
The terms used commonly here on Darker View are ideas that date back to the early beginnings of astronomy. Those ancient astronomers were fascinated by the movements of the bright wandering stars, the planets. They tracked and recorded the motions meticulously and invented the terminology we still use today to describe those motions.

Superior Conjunction, Inferior Conjunction, Opposition and Maximum Elongation tell any experienced skywatcher exactly where a planet is with respect to the Earth, where it is in our sky, and where it will be in the coming weeks or months. It is all part of the intricate patterns of our solar system that allow anyone who learns to become familiar with the night sky.

Continue reading “Elongations, Conjunctions and Oppositions”

Science Illiteracy at the Star-Advertiser

We do like it when Keck Observatory is featured in the local papers. We are proud of the ‘scopes and take notice when we get some good press. The Star-Advertiser is the major daily paper for Honolulu and much of the state. I have even had some of my photographs published in the paper. Another article about Keck appeared today, but this time they simply display their ignorance of basic science.

Keck telescope helps discover 3 small planets outside Milky Way

The headline quickly had my attention. Exoplanet discoveries are coming fast with the Kepler Spacecraft / Keck Observatory team confirming alien worlds at a breakneck pace. It was the “outside the Milky Way” part that had my attention. I had no idea our current technology was capable of that! KOI-961 is a red-dwarf, a small, fairly dim class of star. It is difficult to even detect these stars at great distances, much less get the data needed to confirm orbiting planets. Something wrong here.

I double checked other sources… KOI-961 is actually fairly close to us in galactic terms, a mere 130 light years away. Given that the Milky Way Galaxy is well over 100,000 light years across, it puts KOI-961 well inside our galaxy. The article is actually reasonable, it appears to have simply taken the information from a press release, hard to screw up a cut and paste job. The headline however is where they stumbled hard.

Someone at the Star-Advertiser needs to take a basic astronomy course. Or maybe, simply check Wikipedia!

Update… They have fixed it. I forwarded the link to Larry O’Hanlon, the Keck PIO, whom I work with regularly. He called the S-A and apparently pointed out the issue. I would have loved to listen in on that conversation. The headline and text are edited now on the S-A website, but I kept a screenshot…

 

Outside the Milky Way? Not really...
Outside the Milky Way? Not really...

Venus and Neptune

Venus will pass about one degree from Neptune on January 12th. The two will be quite close for several days, under 3°, from the 10th to the 15th, with close approach on the 12th. As the two are located high in the evening sky they are well placed for observation. This is an opportunity to find the distant ice giant with no difficulty at all. A telescope is required to see Neptune, at about 8th magnitude Neptune is about 60,000x dimmer than Venus shining at -4 magnitude. Check a chart for proper identification, there are several moderately bright stars in the region to confuse with the dim planet. On the 12th, a 6.9 mag star will directly between the two. The odd green-blue color of Neptune should help distinguish the planet.

Yeah, It Was One of Those Days

Can anything go smoothly? Please?

A simple job. Get an 80 pound optical interferometer back under the bench. Nothing like two guys setting the thing on my chest so I can worm my way underneath and heave this beast back onto it’s shelf. Then we have to bolt the fold mirror back in place, another thirty pound piece of awkwardness, just hold it in place to get the bolts in. I hold while Olivier tries to thread the bolts. We also have to replace the pellicle, a bit of ultra-thin optical film that will break if you touch it. Then there is an hour spent aligning the thing. chasing my tail trying to get a properly centered image of the deformable mirror. Sometimes optical alignments just go that way. I finally got a decent image, just to learn there was some vibration in the system. I adjusted some shims to reduce the issue, but there is more to be done.

Much of the remaining day is spent troubleshooting a simple optical shutter in the K1 laser. It fails to completely open. When it fails the safety system detects the failure and shuts down the entire laser. A couple hours of checks later has me convinced that the hardware is working, more or less. The design could have been better. The critical issue is the tight timing requirements. The circuit expects the mechanical shutter to actuate in 50ms, it used to, but as it has been used for a few years, it doesn’t any more. Why they did not simply allow a few hundred milliseconds I have no idea, dumb design, there is no issue with a longer timing window.

One of those days
One of those days on the summit in the K1 laser enclosure
Of course I can not simply change the timing. It is hard coded into a Xilinx CPLD. Give me a few days to setup the Xilinx software, another day or two to understand the code, then maybe I could fix it. I have one day, then the laser is scheduled to be on-sky. Great, time to use my hacking skills to dream up a solution in one day… Tomorrow.

There is a camera in the laser enclosure. We use it for tele-presence. As I worked, Pete, our laser engineer, was on the phone assisting from headquarters. He could run the software remotely and watch as I probed the system to measure the timing. Unbeknownst to me, Pete saved a couple images from the camera and sent them to me. The photo does reveal the day I was having. Thanks Pete… I think.

Employment Opportunity at Keck – Adaptive Optics Opto-Mechanical Engineer

Adaptive Optics Opto-Mechanical Engineer

W.M. Keck Observatory seeks a qualified Opto-Mechanical Engineer at its facilities in Hawaii to join a team that develops optimizes and maintains the Observatory’s Adaptive Optics (AO) systems.

Keck Observatory operates two of the largest and most scientifically productive optical/infrared telescopes in the world. Both telescopes are equipped with operational Laser Guide Star (LGS) AO systems whose capabilities continue to be developed to maintain their scientific competitiveness. The twin 10-meter telescopes are located on the summit of Mauna Kea, at almost 14,000 feet above sea level on the Big Island of Hawaii, one of the premier sites for astronomy.

Responsibilities

  • Opto-mechanical design including analysis, tolerancing and error budgets.
  • Implementation and optimization of opto-mechanical systems including installation and alignment.
  • Maintenance of the AO system opto-mechanics including preventative maintenance,
  • Performance monitoring and troubleshooting.
  • Prepare and review written documentation and drawings for new systems and modifications to existing systems.

Qualifications

  • B. S. in Opto-Mechanical, Optics or Mechanical Engineering or equivalent.
  • Experience with Adaptive Optics or instrument development.
  • Track record of precision designs of opto-mechanical components/systems.
  • Competence with Zemax, SolidWorks or equivalent.
  • Engineering process and documentation experience.

Applications/Resumes are received online only via the website:
www.keckobservatory.iapplicants.com