Mount Pleasant Radio Observatory

16 05 2012

26m Radio Telescope, Mount Pleasant Radio Observatory, Tasmania, Australia

Because you can never have too many radio telescopes, today’s wallpaper features the Hobart 26m antenna at Mount Pleasant Observatory.

Click on the image to go to the download page. Once on the download page, click the button “Give me the matching wallpaper” and follow the provided directions.

Wallpaper Wednesday

11 04 2012

Very Large Array (VLA)

I’m not sure who took this beautiful photo of Antenna 6 of the Very Large Array (VLA), so I can’t credit them. I can, however, tell you to click on the image to download it. I can also direct you to an aerial view of the VLA acquired by the Earth Observatory so you can get some idea of the scale of the array. No. 6 might be the most photographed antenna in the array since it’s on the path of the 1/4-mile self-guided walking tour. The VLA Visitors Center welcomes visitors between 8:30 a.m. and sunset daily. Can’t get there in person? Watch a video of it produced by the VLA Education Officer Judy Stanley and Kate Theisen (saves you $0.25 on the brochure, I guess).

The VLA has been in the process of upgrading to the EVLA for some time now—the project is supposed to finish later this year. Along with new functionality comes a new name: NRAO announced earlier this year that the radio telescope will now be known as the Karl G. Jansky VLA, named for founder of radio astronomy. In 1932, Jansky was the first to detect the radio waves coming from the center of our galaxy, so it seems appropriate to attach his name to one of the longer-lived instruments produced by his discovery.

Wallpaper Wednesday

28 03 2012

Very Large Array. Photo credit: Tom Coates

Today’s wallpaper selection is a bit different. Instead of directing you to one download, I’m giving you a link to several, including the above image. Check out kuriositas’ 10 Spectacular Radio Telescopes Around the World for some beautiful photos. Afterward, come back and place your bets—which one is my favorite?

McDonald Observatory

5 10 2011
Cover, Big and Bright

Cover, Big and Bright

So, to pick up from where I left off in the story of Frank K. Edmondson’s career, I’d like to share a few thoughts on McDonald Observatory.

My last post reported the intellectual and labor connections between Lowell Observatory and the Department of Astronomy at Indiana University (established via W. A. Cogshall). Edmondson did the work for his Master’s thesis on the motions of the globular clusters and galactic rotation at Lowell. After finishing his thesis, he stayed on for another year at the observatory, taking plates for Clyde Tombaugh, before matriculating at Harvard University. He went to Harvard with the understanding that if he finished his Ph.D., there would be a place waiting for him at Indiana University, and that’s just how it worked out. He apparently had to choose between the new  position at Indiana and a more established position at UVa. Howard Shapley counseled him to take the place that had been created for him at IU, because he felt it was more important to expand the number of astronomy posts across the academy than to settle into an established spot at UVa.

At the time, it must have seemed like a strange decision. Edmondson had been working on stellar kinematics (study of the movement of stars), so it would’ve made more sense for him to go work with Alexander Vyssotksy, who was focusing on galactic kinematics and proper motion, at Virginia. But, as we know, Edmondson had many successes at Indiana, including his role in founding a cooperative project between IU, Texas (McDonald Observatory) and Chicago. Actually, Edmondson credited Otto Struve for the start of the project, noting that Struve had published a paper calling for more cooperation in the profession.

From Edmondson’s oral history:

[Edmondson]: “If my memory’s right, Struve’s paper is to be found in the SCIENTIFIC MONTHLY. In the neighborhood of somewhere around 1938, ’39, somewhere along in there. Struve had an article called “Cooperation in Astronomy.” And his basic thesis was — “Look,” he said, “we’re training young astronomers, and then they’re going to schools where they have no telescopes at all, and something has to be done to provide them with the means to continue their scientific careers.”

“So his proposal at that time was to get some university interested in this sort of thing, and go to a foundation to get money for a second telescope at the McDonald Observatory.

“So I wrote to Struve, and asked him for two or three reprints of his article. I said, “I would like to have our President and some of the deans here read what you have written.

“So Struve sent me the reprints, and he said, “I’m also interested in getting going as fast as we can, so here’s my proposal.”

“He said that Vyssotsky had been in communication with him about doing this K star work at McDonald, and Virginia had not been able to raise the funds to pay for the telescope time that would be used for this.”

[Interviewer]: “Is this how you got into the K star work?”

[Edmondson]: “And so he said he was sure Vyssotsky would be willing to cooperate with me. So I got in touch with Vyssotsky. He said, “Oh, yes.” He said, “If you can get the telescope time, I’ll send you charts and everything.”

“So I got back to Struve. Then I got busy here — and the money was provided from here.”

[Interviewer]: “Did you start on the 82-inch at McDonald?”

[Edmondson]: “So we started paying, what was it, $600 a year for 15 nights — it’s a lot more expensive than that now!”

As the interviewer points out, this collaborative effort was “the kernel of what we may now call the National Observatory.”

At the time of the interview (1977), Indiana University was still purchasing time at McDonald. These days, IU works jointly with Wisconsin and Yale at the WIYN 3.5m Observatory on Kitt Peak, but I notice that an astronomer from Texas Christian University is using the 2.1m Otto Struve Telescope at McDonald to study open clusters from the WIYN Open Cluster Study. Astronomy—still a team sport.

So, this is a very long introduction to the book I’ve been reading this week, Big and Bright: A History of the McDonald Observatory by David S. Evans and J. Derral Mulholland (1986). It’s interesting enough on its own, as a history book, but this copy is made even more so by the inscription inside the front cover and a letter that was left tucked inside:

Signature, David S. Evans

Author's signature, David S. Evans

The inscription reads: “For Frank Edmondson with many thanks for your help and hoping we got it right—David S. Evans—8th September 1987”

Letter to Frank Edmondson

Letter to Frank Edmondson from Harlan J. Smith

You can click on the image to see a full-size image of the letter. It reads as follows: “Dear Frank:  As you’ve probably heard by now, the long job of researching, writing, editing, rewriting—even a bit of dissention [sic] now and then—finally came to an end with the UT Press publication of the history of McDonald by David Evans and Derral Mulholland. Your long association with the Observatory more than warrants your receiving a copy of this fine book, and you’ll find many friends and memories in it. David has agreed to inscribe a few copies, including yours, making it a bit of collector’s item as well as plain good fun to read. I think you’ll enjoy it. Sincerely, Harlan J. Smith.”

I hope Prof. Edmondson enjoyed the read. I know I will.


18 08 2011

Using the spectrometers of the Keck and Magellan telescopes to study the origin of supernova. (Original publication of the results in Science can be visited here.)

Wallpaper Wednesday

17 08 2011
Telescope Silhouette

Telescope Silhouette

Today’s wallpaper is a fanciful but eye-catching vector drawing of a small telescope silhouetted against an amazingly starry sky.

First Light

3 08 2011

When the world’s greatest telescopes opened their eyes.

Wallpaper Wednesday

3 08 2011
Westerbork Synthesis Radio Telescope

Westerbork Synthesis Radio Telescope

Today’s lovely wallpaper (click on image to download) shows the Westerbork Synthesis Radio Telescope (WSRT), at the Netherlands Institute for Radio Astronomy (ASTRON), not the Onsala Space Observatory, as the linked page would have you believe. The Westerbork telescope works on the same interferometry principles that determine the design and use of other mobile arrays, such as the Very Large Array (VLA) at the National Radio Astronomy Observatory, the One-Mile Telescope at the Mullard Radio Astronomy Observatory (MRAO), and the Australia Telescope Compact Array at the Paul Wild Observatory. Although you can’t really tell from this photo, one thing that sets this array apart from most is that the telescopes have equatorial, rather than alt-azimuth, mounts.

Quasars, ESO VLT, UKIDSS, and more

4 07 2011
Paranal Platform, home of the ESO's VLT

Paranal Platform, home of the ESO's VLT. Photo credit: ESO/H. H. Heyer

The FORS2 instrument on ESO’s Very Large Telescope (VLT). Gemini North. UKIDSS. Astronomers in Germany. Astronomers in the United Kingdom. Astronomers in Hawaii. A quasar with a mass two million times that of our Sun. That’s the short version of the story. The slightly longer version runs something like this:

The European Southern Observatory is home to the VLT and its array of (mostly) optical instruments. Among those instruments is FORS2 (FOcal Reducer and Spectrograph), a visible-spectrum imager and low-resolution spectrograph.* For the past five years, German astronomers working through the ESO have been searching for a quasar with a redshift higher than 6.5. The higher the redshift, the more distant the object; the more distant the object, the closer the object to the originary moment of the universe. Until recently, the most distant quasars we’ve observed have had redshifts of approximately 6.4.** This means we’re seeing these objects as they were about 870 million years after the Big Bang. We know there are more distant objects out there, but they can’t be viewed with instruments tuned to the visible spectrum. They’re simply too far away; by the time the radiation from these objects reaches us, it’s been so stretched by the expansion of the universe, it can only be detected in the infrared.

Enter the United Kingdom Infrared Telescope (UKIRT) Infrared Deep Sky Survey (UKIDSS). As its name implies, UKIDSS is a consortium of astronomers working together to conduct infrared surveys of the sky using the Wide Field Infrared Camera (WFCAM) on the UKIRT on Mauna Kea. Imagine the celebration when the team discovered a quasar with a redshift of 7 (actually, 7.085±0.003). Now known as ULAS J1120+0641, this new quasar shows us the universe only 770 million years after the Big Bang—100 million years earlier than previously measured quasars. If those numbers aren’t big enough to give you pause, here’s another one to consider:  it took 12.9 billion years for the light from ULAS J1120+0641 to reach us. That definitely qualifies as far, far away.

But the story’s not quite over yet. Before announcing the quasar’s discovery in the journal Nature last week, the research team conducted some follow-up observations at the VLT and Gemini North to confirm the object’s distance from us. I could type for ten more minutes, but that still wouldn’t give me enough time to list all the groups and countries contributing to the VLT and Gemini Telescopes (and my typing speed is quick). I know I’m supposed to be in a state of sadness over the end of the U.S. space shuttle program, and I am, but I’m also heartened daily by the incredible successes of these multi-national, multi-agency, multi-interest projects.

The ESO has made the letter describing the discovery available in .pdf form in its public archives.

* The design of FORS2 and its now-retired twin, FORS1, happened by joint effort of ESO, Landessternwarte HeidelbergUniversity Observatory Göttingen and University Observatory Munich.

**The quasar CFHQS J0210045613 has a redshift of 6.44; SDSS 1148+52513, a redshift of 6.42; and CFHQS J2329+030114, a redshift of 6:42.

Wallpaper Wednesday

8 06 2011
James Webb Telescope Wallpaper

James Webb Space Telescope Wallpaper

Okay, I admit this isn’t the most stunning wallpaper but the James Webb Space Telescope (JWST) is on my mind today since NPR played their story on the cost of the instrument over and over and over this a.m.

As the wallpaper suggests, the JWST is going to be searching for the earliest galaxies, observing the formation of stars from the earliest stages to the development of planetary systems, and looking for signs of life in planetary systems. The telescope is designed to make its observations in the infrared (with limited capability for observations in the visible range of the spectrum) and will carry four separate instruments to do so: the Near InfraRed Camera (NIRCam), the Near InfraRed Spectrograph (NIRSpec), the Mid-InfraRed Instrument (MIRI), and the Fine Guidance Sensor Tunable Filter Camera (FGS-TFI). We already make infrared observations from Earth-based telescopes (at the Keck and Mauna Kea Observatories in Hawaii, for instance), but even at those high altitudes, the earth’s atmosphere can cause blurring. Thus, the need for a telescope outside our atmosphere, 1.5 million km outside our atmosphere, in this case.

To get the wallpaper, click the image and scroll down the downloads page. To get instructions for building a paper model of the telescope, visit the model page. To follow the telescope on twitter, look for @NASAWebbTelescp.