Chargers

No, this isn’t a post about a football team that started in Los Angeles, moved to San Diego, then returned to Los Angeles. This past week, I operated the WIYN telescope at Kitt Peak National Observatory. About halfway through the week, the charger circuit on the telescope failed. The WIYN is a telescope with a 3.5-meter primary mirror, making it the second largest aperture optical telescope at the observatory. This large telescope needs to track the sky as smoothly as possible to get the precise measurements we make of astronomical objects. Because of that, the motors don’t actually work off a power cord plugged into the wall that could be subject to brown outs or power spikes. Instead, we have a charger circuit that charges up a set of small batteries. The telescope drives actually are powered by the batteries, shown in the photo to the left.

Although I have some experience with electronics, I’m not actually an electrical engineer. When failures like this occur, my job is less to make a repair, but to see if I can find a way to limp along for the rest of the night and continue to take data in spite of the trouble. However, the circuit is so fundamental to the telescope’s operation and the problem bad enough that I couldn’t even limp along. We had to close up and wait for more expert help in the daytime.

Fortunately, our expert electronics crew was able to repair the charger circuit in less than a day, so we were back on sky and taking spectra of galaxy clusters the next night. What has always amazed me about the charger circuit on the WIYN telescope is that a bank of relatively small batteries can move a 3.5-meter telescope. Those batteries need to move the telescope in three axes. The obvious axes are altitude and azimuth. As WIYN tracks the sky, images rotate in the field of view, so there’s also a rotator that keeps north up in the images.

The charger system strikes me as a metaphor for my approach to seeking inspiration for my writing. The charger system takes current from the wall in whatever form it exists, uses it to charge batteries, which change the form of the current to produce good telescope motion. I take inspiration from my work in astronomy, from the books I read, the movies I see, and my time interacting with friends and family, allow myself to process that through my brain and turn that into the stories and novels I write.

I have taken variable star data with telescopes that use wind-up clock drives and that has helped to inspire and inform clockwork gadgets in my steampunk stories. I once helped an astronomer to take one of the deepest images of the center of our galaxy in the infrared, which helped me to imagine a voyage to the center of the galaxy in my Space Pirates’ Legacy novels. Working late nights on a lonely mountain top in meandering buildings informs my horror. If you’re a writer, I’d love to hear about some things that have inspired your writing in the comments below.

Explore the worlds I’ve created at http://www.davidleesummers.com

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Assembling the Puzzle

This has been another week helping to install the Dark Energy Spectrographic Instrument or DESI at the Mayall 4-meter telescope at Kitt Peak. In short, the goal of DESI is to study the effect of dark energy on the expansion of the universe. We plan to collect spectra of tens of billions of galaxies and quasars with the goal of making a three-dimensional map of the universe out to about 11 billion light years. You can read more about the DESI project at https://www.desi.lbl.gov/

The DESI project is spearheaded by Lawrence Berkeley Lab in California and being installed at Kitt Peak in Arizona. However, it really represents a worldwide collaboration. There are scientists working on this project from England, France, Spain, Italy, South Korea, China, France, Canada, Colombia, Australia, and others plus numerous institutions within the United States. All of these agencies are not only contributing expertise, but actually building components that will go into the finished instrument.

In an earlier post, I spoke about how we worked to remove the Mayall telescope’s original top end. The top end originally housed both a secondary mirror and a prime focus camera. Both of these have been used to make groundbreaking discoveries over the last five decades. The Mayall was the telescope Vera Rubin used to study rotation curves of galaxies, which led to the discovery of dark matter. I’ve helped with observations that have led to the confirmation of numerous exoplanets. We’re now replacing the telescope’s original top end with a new one that will hold 5000 fibers at prime focus. Each of those fibers will run to spectrographs that will break up the light from objects in the sky so it may be analyzed and the position of the object can be measured. In the photo above, you can see the new top end being assembled to the left of the telescope.

To get light from the sky onto the fibers, the telescope will collect it with the primary mirror. That sits in the big white structure at the center of the big blue horseshoe-like structure in the photo above. The mirror will direct that light to the top end. Because the mirror is curved, allowing the light to be collected and redirected, it means the focus changes across the field of view. To deal with that, you need to put some lenses in front of the fibers, sort of like glasses. Another real world problem of telescopes is that as you point toward the horizon, light gets spread out. So you need optics to compensate for where you’re pointing in the sky. Sort of like glasses that automatically adjust themselves for where you’re looking.

Scientists from England assembled those specialized “glasses” for the telescope. Those arrived last week and I was on hand during their assembly at Kitt Peak. You see those assembled optics in the lower photo. Scientists from Italy built the “Hexapod” pointing system, which keeps those optics aligned. That arrived and was tested about a month ago. Scientists from Fermilab in Chicago are responsible for integrating those systems and putting them together in the top end ring. That process will start next week. It’s all quite a puzzle and it’s been remarkable to see it all come together. It’ll be even more amazing to see what science it yields.

Of course, work at Kitt Peak helps to inspire my science fiction. As a reminder, this is the last weekend of the Smashwords Summer/Winter sale. You can learn about my science fiction books that are on sale at:

We also have fantasy and steampunk titles on sale. You can learn about them at:

Ramping up the Refit

This past week, I’ve continued my work supporting the refit of the Mayall 4-meter telescope for the upcoming DESI spectrograph. DESI is the Dark Energy Spectroscopic Instrument and it will be capable of measuring of the spectra of 5000 objects at a time. Its mission objective is to collect data to help us understand the nature of Dark Energy in the universe. We don’t yet know what Dark Energy is, all we really know is that appears to make the expansion of the universe accelerate with time. To be able to collect these 5000 spectra, the telescope needs a new top end. Indeed, the first thing I saw when I came to work on Monday morning was the old top end sitting on a flatbed trailer outside the telescope being ready to go into storage.

The Mayall 4-meter is a reflecting telescope and the primary optical component is a big 4-meter diameter mirror at the bottom. The light from that mirror is then focused at that top end and either collected by a camera sitting there at “prime focus” or a sent down to an instrument underneath the telescope using a secondary mirror. The top end held both the prime focus and the secondary mirror and could be flipped end-for-end to allow either to happen. DESI will have its 5000 fibers in a new top end and indeed, part of the reason for selecting the Mayall was to have a telescope sturdy enough to handle that large an instrument. At the moment, the telescope is missing its top end, but the new one will be installed soon. There are work platforms, which enabled people to loosen the old top end so it could be lifted out with a crane. The work platforms also keep the telescope structurally stable while there’s no top end in place.

The top end only holds part of the instrument. It will have 5000 optical fibers which may be precisely positioned onto target objects. The light from those fibers is sent along the fibers to spectrographs in an environmentally controlled room where the light will be spread out and photographed so it can be analyzed. In the dark energy survey itself, most people will be looking at the so-called redshift—how far the characteristic spectral “fingerprint” of certain chemicals shifts to the red as a result of its velocity away from us. However, those same chemical fingerprints may be used to understand properties of the objects being looked at and this data will be available to anyone who wants to use it.

Because dark energy is an exciting topic in its own right, but also because this project will be generating so much raw data that’s useful to so many astronomers, it’s a major worldwide undertaking. To break the light from the fibers into spectra will require ten spectrographs which will reside in a carefully climate-controlled room. An exciting milestone I got to watch this week, was unpacking the first of those spectrographs when it arrived from France. Below, you can see the engineers inspecting the optical elements. Note the rainbow visible on the corrector plate of the right-most optical element. That’s exactly what this device is built to do! Break the light into rainbows.

Today finds me in Phoenix, Arizona for Leprecon 44. If you’re in town, I hope you’ll drop by and check out some of the panels and workshops.

NEID – A New Way of Seeing Exoplanets

Last week, I talked a little about the work we’re doing refitting the Mayall 4-meter Telescope for the Dark Energy Spectrographic Instrument. However, it’s not the only construction going on at Kitt Peak. The WIYN 3.5-meter telescope, which I also work with, is getting a new spectrograph installed called NEID. Deploying NEID doesn’t require a full telescope refit like deploying DESI, but there’s still quite a bit of work happening in the building.

Most of the work right now is going into building a new bench spectrograph room. NEID is an acronym for “NN-explore Exoplanet Investigations with Dopler spectroscopy”. The word “neid” is also the Tohono O’Odham word meaning “to see.” An appropriate choice, given Kitt Peak’s location on the Tohono O’Odham Nation in Southern Arizona. The goal of NEID is to provide the astronomical community with a state-of-the-art Doppler spectrograph to investigate exoplanets around nearby stars.

The way this will work is that an optical fiber assembly will be mounted to the telescope itself at the port in the photo to the right with the sign on it. That optical fiber will carry the light from the star to the new bench spectrograph downstairs where it will be spread out, like a rainbow. The reason for doing this is not to see a pretty rainbow, but to see dark lines interspersed through the rainbow. Those dark lines are like the star’s chemical fingerprint.

Now, here’s the fun part. When a planet moves around the star, it drags the star just a tiny amount toward the Earth which causes that spectral fingerprint to shift a little bit toward the blue end of the spectrum. When the planet passes behind the star, it drags it away from the Earth and moves the spectral fingerprint toward the red end of the spectrum. Looking for this shift is the “Doppler” approach to finding planets that NEID will employ.

In addition to discovering new planets, NEID will be used to follow up observations by NASA’s Transiting Exoplanet Survey Satellite (TESS) and will help to determine masses and densities for planets TESS discovers. By the way, the NN-Explore that’s part of NEID’s acronym stands for NASA-NSF-EXoPLanet Observational REsearch. The current plan is to begin commissioning the instrument this fall and for regular observations to commence in 2019.

Being part of on-going research into planets around other stars is what inspired Dr. Steve Howell of NASA’s Ames Spaceflight Center and I to invite science fiction writers to imagine what these planets around other stars might be like. The results were our two anthologies, A Kepler’s Dozen and Kepler’s Cowboys. You can learn more about the anthologies by clicking on their titles.

Once NEID goes online and starts making discoveries, Steve and I may have to “see” into the future and collect a third anthology. This time, including stories about planets discovered by a telescope on a mountaintop in Arizona’s Tohono O’Odham Nation.

Refitting the Mayall: Teardown

I was in 8th grade when Star Trek: The Motion Picture came out. One of the things that fascinated me in that movie was the refit of the Starship Enterprise. I was captivated by how the ship looked at once much the same and yet completely different. It looked sleeker and more powerful and familiar space on the ship such as the bridge, sickbay, and the transporter room had all been updated. I’m getting to experience something much like the Enterprise refit in real life. In this case, I’m involved in refitting the Mayall 4-meter telescope at Kitt Peak National Observatory.

Like the Starship Enterprise, the Mayall has a forty-five year history of discovery. Originally built to use photographic plates, the telescope has played an important role in such discoveries as establishing the role of dark matter in the Universe from measurements of galaxy rotation, and determining the scale and structure of the Universe. Over the years, new instrumentation has been added to the telescope including advanced digital cameras and spectrographs.

The purpose of the refit is to install a new instrument called DESI, which stands for Dark Energy Spectroscopic Instrument. 5000 optical fibers will be installed at the telescope’s prime focus (the top end of the telescope) and run to cameras in another room. The goal is to observe tens of millions of galaxies and quasars, constructing a three-dimensional map spanning the nearby universe to 10 billion light years.

In order to achieve this goal, the entire top end of the telescope has to be replaced and much of the control software and electronics are being redone so that it’s truly state of the art. To achieve this goal, we literally have to gut the telescope and install new components from the inside out. During my most recent shifts at the telescope, I’ve been involved in just that. In the photo to the right, you can see that the bottom of the telescope is missing and replaced with scaffolding. That’s because the large 4-meter mirror is out for recoating. Also, all the optics are missing from the secondary mirror assembly at the top of the telescope. Ultimately, that will be removed completely and replaced with a new secondary ring. The men in the photo are removing a counterweight assembly used to precisely balance the telescope when instruments are added and removed. Electrical panels are open on the side of the telescope where control cabling going back to the photographic days will be removed and replaced with new control cabling. Modern electronics mean the telescope will have about 10% of the cables as it did when originally built!

The refit has also allowed me a rare opportunity to see parts of the telescope I’ve never been to before, even after operating it for some thirteen years. Earlier this week I got to help the electronics technicians work on some cabling in the “horseshoe.” That’s the big, blue horseshoe-shaped mount you see in the photos above. We actually ended up working down in the broad, blue, oval-shaped tube you see in the photo just above. I dubbed it the sinking submarine, because it’s a cramped space and we were standing at a 32-degree angle relative to the ground!

It’s going to be exciting to watch the telescope take shape again after the teardown process. New parts will be arriving in the coming months. A large crane will be deployed outside the 4-meter to lift out the old secondary ring and bring in the new one. The plan is to be back on sky to test components of the new instrument later this year. Once those tests are completed, other components will be finished, revised if needed and then installed. At that point, the Mayall’s new five-year mission to map the universe will begin.


Finder Scopes

One of the things I like about working at Kitt Peak National Observatory is that my job has a lot of variety. I contribute to important science projects and I help with engineering that helps to achieve the observatory’s science goals. Sometimes I act as something of a councilor, commiserating with observers during inclement weather. I even get to employ my writing skills when documenting tasks for our operations manuals.

This past week, one project I helped with was testing a new finder scope for the 4-meter telescope. Finder scopes don’t often get a lot of attention, but they serve an important function. Telescopes often give you such an enhanced view of the sky that it’s difficult to know exactly where you’re pointed. A finder scope is simply a smaller telescope mounted to the bigger telescope that lets you see a wide swath of the sky and confirm that you’re looking where you think you should be. Even my 90mm telescope has a finder scope on it. It’s the little tiny telescope piggybacked on the bigger telescope.

Here’s a view of the finder scope mounted to the top of the 4-meter telescope at Kitt Peak. Note that it’s basically just a camera lens directing light into a little digital camera.

This will prove vitally important when we start using the DESI spectrograph on the 4-meter. With that instrument, we’ll have fibers directing most of the light to spectrographs instead of a direct view of the sky. We will have a guide camera, but if, for some reason, the telescope pointing is off, it may be hard to find where we are. Because of that, it’s nice to have a widefield view of the sky. The images taken with the finder scope won’t be the ones you see in most magazines, but still, we played a little while testing and took a nice photo of the Andromeda Galaxy, M31 and it’s companion, M110.

We also took an image of the Pleiades, which is a nearby open cluster visible with the naked eye. These are young stars with nebulosity still around them. Even with our small telescope, it only took 30 seconds to see some of the nebular clouds.

Speaking of variety, another job I did this week was help an astronomer monitor a Jupiter-sized planet as it transited its star. This planet had a rotational period of only 1.6 days and we monitored it with the WIYN telescope at the same time the Kepler Space Telescope monitored it. Having two telescopes monitoring it at the same time allows for scientists to confirm and double check results. The system we were watching is very much like system I wrote about in the anthology A Kepler’s Dozen. You can learn more about the book and find places to order at http://www.davidleesummers.com/Keplers-Dozen.html. The book gives a unique look at the types of worlds discovered by the Kepler Space Telescope. My co-editor on the project was Dr. Steve B. Howell, head of the Astronomy and Astrobiology Division at NASA’s Ames Research Center.

Hunting Asteroids

I rang in the new year by helping Robert McMillan, Jim Scotti, and Melissa Brucker from the University of Arizona hunt for potentially hazardous asteroids in our solar system at the Kitt Peak 4-meter telescope. This is important work since asteroid impacts are one of the few completely predictable and preventable natural disasters. Here I am at the telescope console.

As it turns out, this observing run was something of a bittersweet milestone. Bob, Jim, and Melissa are the last scheduled visiting observers on the 4-meter. At this point, we have about five more weeks of observing with a scheduled imaging survey program and then the telescope shuts down so it can be refitted with an instrument called the Dark Energy Spectroscopic Instrument, or DESI. DESI will measure the effect of dark energy on the expansion of the universe. It will obtain optical spectra for tens of millions of galaxies and quasars, constructing a 3-dimensional map spanning the nearby universe to 10 billion light years.

So, what about the asteroids? Well, the good news is that there are smaller telescopes on Kitt Peak devoted to the search. The reason Bob, Jim, and Melissa use the 4-meter is that it allows them to look for more distant asteroids on nights when the small telescopes are not as effective. In this case, we were attempting our observations during the full moon. Because the moon is so bright, it’s hard to see faint, distant objects with small telescopes because you need to expose on the sky for a long time. The 4-meter can take shorter exposures and still detect these faint objects without having the skylight swamp the exposures. In the meantime, Bob, Jim, and Melissa have applied for time on other telescopes around the world to do the work they were doing on the Kitt Peak 4-meter.

Often times when I’m involved in these runs, I’m asked if I’ll let people know if something is going to fall on us. Well, if I know, I’ll tell. However, what we often do is identify small objects a long ways away. It’ll usually take more than the observations we get to determine the object’s orbit and find out whether or not it presents a serious hazard.

So what actually happens if we discover an asteroid that might hit the Earth? I found this NASA video that gives a nice explanation. I notice there is also an image credit from my friend Mike Weasner, a talented amateur astronomer who is also a science fiction fan.

If you want to get more of a sense of what life is like behind the scenes at an astronomical observatory, be sure to read my novel The Astronomer’s Crypt. You can learn more about the novel and get a sneak peak at http://www.davidleesummers.com/Astronomers-Crypt.html