Exploring Galaxies

This past week, I’ve been working at Kitt Peak National Observatory’s WIYN telescope using one of the workhorse instruments called HexPak to help astronomers better understand how galaxies work. At left is a photo I took of the galaxy M51 with the New Mexico State University 1-meter telescope. While we can learn a lot studying photos like this, wouldn’t it be nice if we could learn more, and understand what chemical elements make up the different parts of a galaxy? The instrument HexPak is designed to do just that.

One of the best tools we have for understanding the chemistry of objects in space is spectroscopy. Back in the nineteenth century, it was discovered that if you looked at heated elements through a spectroscope, you would see a characteristic set of lines in the rainbow-like spectrum. These lines are like a fingerprint for each element. It turns out that stars are really good at heating up elements! Below is a photo of the WIYN telescope with HexPak mounted.

HexPak is the white hose-like thing on the right plugged into side of the telescope. Inside that hose-like unit is a bundle of optical fibers arrayed in a hexagonal pattern. They look like this:

We can then align those fibers with a galaxy like M51 above, so different parts of the galaxy line up with different fibers. When that’s done, it looks something like this:

Now, I should note, this image was created just for illustration purposes. I haven’t tried to match the scale or alignment of my NMSU 1-meter image of M51 with the HexPak fiber array. However, you will see that different parts of the galaxy now line up with different fibers. That light is now sent downstairs to a bench spectrograph where it’s broken into its component parts. Here’s WIYN’s bench spectrograph. You can even see the rainbow like spectra on the grating at left we use to analyze the light from galaxies.

Light from each of the fibers in the array becomes a single spectrum and the image of that spectrum is recorded on a camera, shown at the right of the image above. Each one of those spectra will tell us about the elements present in each of the parts of the galaxy as lined up above. So, for example, you can figure out if the spiral arms have different amounts of a certain element than the bulge in the center. You can see what’s going on in the space between the galactic arms. If you look closely at my photo of M51, you’ll see it has bright regions that line up with parts of the spiral arm. An instrument like HexPak can help an astronomer learn if those parts of the spiral arm are different from other parts of the spiral arm, and maybe see what those regions are made of.

As I’ve mentioned in other blog posts, this work does inspire my writing. Sometimes I look at a galaxy like one we study with HexPak and think what it would be like travel between the different parts of a galaxy. M51 has a lot in common with our own galaxy. What’s it like in the arms? What’s it like between the arms? What’s it like the galaxy’s center? What’s more, working with astronomers in the control room sometimes does feel like being a crewmember on a spaceship exploring uncharted reaches. All of these elements have influenced science fiction stories like Firebrandt’s Legacy and The Pirates of Sufiro. I’m getting ready to release the former and I’m rewriting the latter with help from supporters at my Patreon site.

You can get involved in the fun by becoming a patron. My patrons are the first people who get to read new stories in my science fiction universe and they get to download complete books when they’re available. What’s more, one of my goals at my Patreon site is to make this blog ad free. If you like behind-the-scenes looks into astronomy like this one, but don’t like the ads at the blog, please consider supporting my Patreon site at: http://www.patreon.com/davidleesummers

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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.

On Turning 50

Over the weekend, while at TusCon in Tucson, Arizona, I celebrated my fiftieth birthday. It’s one of those points in life where I find myself looking back to see where I’ve been as well as looking forward to see where I’m going.

david-at-50

In my first fifty years, I’ve written and published nine novels, eighty-four short stories, and fifty-four poems. I’ve edited three anthologies, plus two magazines for ten years each. I contributed to the commissioning of the WIYN 3.5-meter telescope and the NMSU 1-meter telescope. I’m co-discoverer of two variable stars and I helped take data that contributed to the discovery of dark energy. Most of all, I’m proud to be the father of two incredible young ladies, one in high school, the other in college, who have a wide range of talents in such areas as computer science and mathematics.

Looking ahead, my tenth novel, The Astronomer’s Crypt, is nearing release. I have two anthologies in the publication queue: Kepler’s Cowboys and Maximum Velocity: The Best of the Full-Throttle Space Tales. I have four short stories accepted and awaiting publication. Beyond that, I’m in the early phases of writing a new novel and I have a “fix-up” novel a little over half completed. Plus I have story treatments for four more novels. Presuming no major funding shifts, I expect to be involved in commissioning two new instruments at Kitt Peak in the coming years.

As I reach fifty, I’m arguably in the best health I ever have been. The arthritis that plagued me for years is in remission and I regularly take long walks through my neighborhood. Nevertheless, one specter looms over me. My dad was only fifty-two when he died suddenly of a heart attack. In the plus column, my doctor is helping me watch my heart health and both of my brothers have now outlived my dad by over a decade. I have no immediate reason to fear for my imminent demise. Nevertheless, I find myself grieving for how truly short my dad’s life was cut and watching my health has taken on a new urgency.

In short, as I turn fifty, I feel proud of what I’ve accomplished. My regrets are minimal. While there are some harsh words and rash actions I’d take back if I could and some friends I’ve lost touch with over the years, it’s hard to say I’d have a better life if I’d taken a different path. I have several exciting things to look forward to in the coming months and years, plus plans and goals for the years beyond that.

Thanks to my readers for sharing some of this fifty-year journey with me. I look forward to sharing the coming years with you as well.

Collimating WIYN

About a week ago, I was assigned the task of collimating the primary mirror on the WIYN 3.5-meter telescope at Kitt Peak National Observatory. Large telescopes like the WIYN work by using large mirrors to collect and focus light from distant stars onto a camera or a spectrograph. When the telescope is disassembled for regular maintenance, the mirrors have to be precisely realigned so that we get the very best possible image quality. Here you see a photo of me with my daughters in front of the WIYN primary and tertiary mirrors.

With Daughters at WIYN

Although I work with optical telescopes all the time, my specialties are more in the electrical and mechanical aspects of telescopes than with the optics, so this precision job was, to be honest, pretty scary. Sure, I’d helped the site engineer collimate the telescope plenty of times, but this time he left me with a set of instructions and went off to bed. I did my best, followed the instructions and everything seemed to go well. It was especially gratifying over the next three nights when the visiting astronomers reported getting half-arcsecond images. What that means is that stars subtended no more than half a second of arc on the sky, which is pretty tiny. That also means we’re minimizing the blurring one would expect to see from the atmosphere. I have to say, it’s the kind of thing that makes me feel pretty good.

The whole idea of characters being challenged to do new things they didn’t think they could do is an important part of my fiction. Recently, in Lightning Wolves, Larissa Crimson is challenged to find a way to make a set of unwieldy lightning guns portable enough to be practical in combat. She’s not sure if she has the skills necessary to do the job, but she gives it a shot and finds a solution.

WIYN’s newest instrument is a camera called the One-Degree Imager. It’s a camera that takes pictures of a large swath of the sky at high resolution, which means you can see things at great detail. If the telescope mirrors are misaligned, the camera cannot take pictures with the kind of detail it was designed for. So, the litmus test for the alignment exercise came this past Monday, when an observer took images of globular clusters with the One-Degree Imager. She also reported half-arcsec images, much like in the photo below. This photo, by the way, was taken with WIYN, but with the old mini-Mosaic camera before the One-Degree Imager was implemented.

A.Saha (NOAO)/WIYN/NOAO/NSF

A.Saha (NOAO)/WIYN/NOAO/NSF

Globular clusters such as the one shown above, are immense balls of ancient stars that orbit our galaxy. As it turns out, they feature prominently in my Old Star/New Earth series. Those novels are:

The ebook of the first novel is free. The paperback editions feature wonderful illustrations by Laura Givens. So, why don’t you start an epic voyage to the stars today!