Saturday, May 31, 2008

The Year of Astronomy is Coming

2009 marks the 400th anniversary of Galileo's first astronomical observations. The International Astronomical Union and UNESCO has proclaimed 2009 to be the International Year of Astronomy. Celebrations will take place in the United States and throughout the world. 2009 also marks the 60th anniversary of the first light and first scientific observations for the Hale Telescope on Palomar, giving us extra reasons to celebrate.

At the moment I am in St. Louis, MO attending meetings run by the Astronomical Society of the Pacific and the American Astronomical Society on the International Year of Astronomy. Details about the some of the celebrations will be posted here and on the Palomar Observatory website when they become available. Stay tuned.

Thursday, May 29, 2008

Astronomer Maarten Schmidt Honored

From Caltech Today:
Astrophysicist Wins One of First Kavli Prizes

Quasars, now known to be compact halos of matter that surround the massive black holes of distant galaxies, were once thought to be stars in our own galaxy. Now, Maarten Schmidt, who first showed that quasars are thousands of millions of light years away from Earth, has been named one of the first recipients of the $1-million Kavli Prize for his contributions to the field of astrophysics. Schmidt, the Moseley Professor of Astronomy, Emeritus, at the California Institute of Technology, is one of seven recipients of the new Kavli Prize. He shares the astrophysics award with Donald Lynden-Bell of Cambridge University, who was also a postdoc at Caltech from 1960-1962.
Schmidt did his quasar work on the Hale Telescope in the early 1960s. He received national attention for it and was on the cover of Time Magazine March 11, 1966. A good account of his quasar and other research can be found in First Light by Richard Preston.

Update: Read the full press release here.

Saturday, May 24, 2008

Support Your Local Mirror

The Hale Telescope's 14.5-ton mirror is honeycombed on its underside. The triangular pieces are hollow to reduce the weight of the Pyrex disk. The round areas are the locations of the mirror supports.

The mirror supports are truly remarkable devices. From The Perfect Machine: "The thirty-six supports were precision machines, an assembly of levers, counterweights, gears, and ball bearings like a fine wristwatch, but large enough that it took two men to carry each of them."

"The design of the support mechanisms was clever. The levers of the mechanisms were designed to push up, against the tops of the pockets in the back of the disk, to counteract the force of gravity pulling down on the disk. The supports were four inches behind the actual surface of the disk."

Each of the 36 mechanisms has 33 different places where something can rotate, slide, or pivot (That's 1188 degrees of freedom!) to change the tension on the surface to ideally keep the mirror in its perfect parabolic shape.

All of this happens by gravity alone, there is no active control (Maybe someday, but not now). As the telescope pivots to point to a different location in the sky the pieces within the supports relocate and change their tension on the mirror.

Over the years pieces within the mirror supports can bind up a bit, limiting how easily the parts can move and how effectively the mirror's shape is maintained. During the recent engineering run one of the mirror supports was removed and examined in great detail.

Here is a photo of the mirror cell with the instrument removed from the Cassegrain cage. The big hole at the top is the where the light comes through to the science instrument. The red fans are fans that can blow air on to the backside of the mirror to help the mirror reach the proper temperature. All of the rest of the openings on the mirror cell are locations of mirror supports.

A close-up photo of one of the mirror supports.

More on the mirror supports and something that may surprise you later.

Wednesday, May 21, 2008

A Supernova Caught in the Act!

A long time ago, in a galaxy far, far away . . . . there was a star that exploded. 90 million years later astronomers observed the event with telescopes located on both on Earth and in Earth orbit.

The galaxy is known as NGC 2770, found in the constellation Lynx. Back in December the supernova, SN 2007uy, was observed. That in itself isn't too amazing as new supernovae are observed in various galaxies relatively often. Within one particular galaxy they aren't too common, perhaps occurring once or twice per century.

On January 9th former Caltech astronomers Alicia Soderberg and Edo Berger, now with Princeton University was observing the supernova with NASA’s Swift satellite when they caught a new one, located within the same galaxy, in the act of exploding.

Of the many thousands of previously observed supernovae, this was the first one actually observed as the explosion was taking place. Most of them aren't caught until hours, days or weeks after the event. The discovery will be described in a paper ("An Extremely Luminous X-ray Outburst Marking the Birth of a Supernova") to be published in tomorrow's issue of the journal Nature.

A veritable fleet of telescopes, on Earth and in space, were quickly called into action to observe the new supernova, now known as SN 2008D. Caltech's observations were led by Shrinivas Kulkarni, MacArthur Professor of Astronomy and Planetary Science and director of Caltech Optical Observatories. Caltech astronomers including graduate student Bradley Cenko and others undertook detailed observations with the automated Palomar 60-inch and the 200-inch telescopes.

Captured by the Palomar 60-inch telescope, here is NGC 2770 with both of the supernovae marked:

Image Credit: A. Rau (Caltech)

Joining Swift and the Palomar telescopes in making observations of the event were the Hubble Space Telescope, the Chandra X-ray Observatory, the Very Large Array in New Mexico, the Gemini North telescope in Hawaii, the Keck I telescope in Hawaii, and the 3.5-meter telescope at the Apache Point Observatory in New Mexico.

What have we learned? This particular supernova was produced as the core of a massive star collapsed likely producing an ultra-dense neutron star. The newborn neutron star then rebounded, triggering a shock wave that blew the stars outer layers off and into space. Swift caught the flash of X-rays produced as the star blew apart.

The observations also show that SN 2008D is an ordinary Type Ibc supernova, which occurs when a massive, compact star explodes. Significantly, radio and X-ray observations confirmed that the event was a supernova explosion, and not a related, rare type of stellar outburst known as a gamma-ray burst.

Be sure to check out the Caltech press release and the NASA press release on the findings.

Friday, May 16, 2008

And Then There Were Two

The Thirty-Meter Telescope (TMT) is one step closer to reality. After years of study, the site selection team has narrowed the search to just two possible sites to build what will be come the world's largest telescope. They are Cerro Armazones in Chile's Atacama Desert, and Mauna Kea on Hawai'i Island.

Each site offers the excellent conditions needed for an observatory of this magnitude. What's required? A high elevation; clear skies; stable, non-turbulent air; and a dry atmosphere.

From yesterday's press release:

"The TMT is currently in the final stages of an $80 million design phase. The plan is to initiate construction in 2010 with first light in early 2018. This project is a partnership between the University of California, California Institute of Technology, and ACURA, an organization of Canadian universities. The Gordon and Betty Moore Foundation has provided $50 million for the design phase of the project and has pledged an additional $200 million for the construction of the telescope, and Caltech and the University of California each will seek to raise matching funds of $50 million to bring the construction total to $300 million."

Stay tuned as the best is yet to come.

Wednesday, May 14, 2008

WorldWide Telescope

It is an exciting time to be alive if you are interested in astronomy. There is more astronomical images and information available your fingertips than ever before. Adding to this comes yesterday's release of the WorldWide Telescope (WWT) from Microsoft. I haven't had the chance to try it yet, but it should give remarkable images from a wide-range of telescopes based on Earth and in space. Included among those telescopes is Palomar's very own 48-inch Samuel Oschin Telescope.

The 48-inch is a wide-field Schmidt telescope (also called a Schmidt camera) that was built for surveying the sky. Images of the northern sky used in WWT were obtained from the Second Palomar Observatory Sky Survey (aka POSS-II). The pictures for the survey were first recorded on large (14" inches on a side!) glass photographic plates. They were then scanned at the Space Telescope Science Institute in Baltimore, Maryland. From there they were processed and calibrated at Caltech under the leadership of Caltech Professor of Astronomy S. George Djorgovski. This survey has detected over 50 million galaxies and about a billion stars, as well as many other interesting objects.

The WWT also has data from the ongoing Palomar-Quest digital sky survey, also performed with the 48-inch Samuel Oschin Telescope. The glass photographic plates are now long gone, the Palomar-Quest survey makes use of a 161-megapixel camera. Don't forget to read the full press release on Palomar & Caltech's involvement in WWT.

Shown below is one of many infrared images of M81 that you can see on WWT. The image comes from the Spitzer Space Telescope.

Saturday, May 10, 2008

Happy Astronomy Day

Today is Astronomy Day! Lots of places around the country are hold events. In San Diego, the Ruben H. Fleet Science Center will be having a wide-range of events including a live broadcast from Palomar hosted by me.

Here at Palomar we are celebrating by having an engineering run. During the engineering run members of the staff here will make repair and improvements to the telescope's mirror supports, wiring, and dome rails. There's a lot of work going on.

I have been going around taking pictures and yesterday I put together two 3-D shots of the Hale. So if you've got red-blue glasses, put them on and click on the images below.

I'll post more images from the engineering run soon, but don't expect to see them in 3-D.

Oh, for those of you keeping score at home it was on this day 60 years ago that it was announced that the name of the 200-inch telescope would be the Hale Telescope. More on that later.

Wednesday, May 7, 2008

Asteroid San Diego

24 years ago this week the City of San Diego was honored for its efforts in helping to control light pollution. The honor came as an asteroid was named "as a celestial tribute to the City of San Diego in appreciation of the city's responsiveness and cooperation in the campaign to restore dark skies of astronomers probing the universe."

We hope that commitment will continue well into the future as new lighting technologies come into use. Preserving dark skies might help us to find any potential dangerous asteroids before they become a threat

Asteroid 3043 San Diego (the streak above) was discovered at Palomar by astronomer Eleanor Helin on September 30, 1982.

Speaking of dark skies, the effort continues in Borrego Springs to make it the next International Dark-Sky Community. Yesterday, Dennis Mammana, was on KPBS radio's These Days speaking about light pollution. You can listen to the archived version of the show here.

Just Hop on the Bus, Gus

Autoblog Green is reporting that the first natural gas hybrid bus is now running in San Diego. This may be of interest to fans of Palomar Observatory, not just because the bus is green, but because the side of the bus features a mural of 50 attractions in San Diego County. Included in the list is, you guessed it, Palomar Observatory.

An interactive version of the mural is available on line. Be sure to check it out and pass your mouse over Palomar Mountain to see a large view of the dome, complete with spiral galaxy in the sky.

Special thanks go out to Francis French of the San Diego Air & Space Museum to giving me the news.

Tuesday, May 6, 2008

Shattered Comet

Two years ago this week Caltech astronomers were using the 200-inch Hale Telescope to observe the fractured Comet 73P/Schwassmann-Wachmann 3 as it came relatively close to Earth.

The comet was discovered by Arnold Schwassmann and Arno Arthur Wachmann in 1930. In 1995 the comet was found to have broken up into four fragments in 1995. By its 2006 passage it had further split into dozens, if not hundreds, of pieces.

The animated gif above shows a sequence of 15 looped images showing the in the foreground against distant stars and galaxies which appear to streak across the frame. Because the comet was moving at a different rate across the sky than the stellar background, the telescope was tracking the comet's motion and not that of the stars. Many fragments of the comet are visible as nearly stationary objects in the movie. In all, 16 new fragments were discovered as a part of the Palomar observations.

Friday, May 2, 2008

In the News . . .

Here's a sampling of some of the recent media activity associated with the observatory.

We had three documentary film crews here in April. National Geographic Channel's new series Known Universe was here to interview Caltech's Mike Brown. San Diego City College's Newscene was here to do a story on light pollution. A production crew for the History Channel's Modern Marvels was here to do a story on JPL's Near-Earth Asteroid Tracking (NEAT) program & asteroid "crashes".

Here they are filming in the data room for Palomar's 48-inch Samuel Oschin Telescope. Look for the show to air sometime in July.

Yesterday the San Diego Union Tribune newspaper ran a story, Dark skies, bright future, on light pollution and the effort (supported by Palomar Observatory) to make Borrego Springs the next International Dark-Sky Community.

Finally, I just did an interview about the observatory for the Treehuggers International with Tommy Hough radio show. Look for that to most likely air early (5:30 am PDT!) on Mother's Day (May 11) and on their website soon after.