Wednesday, June 29, 2011

Happy Hale Day!

For those of you keeping score at home, George Ellery Hale was born 143 years ago today.

Hale can been seen in the photo above (on the right) talking with his arms linked with an enraptured Andrew Carnegie. It is one of my favorite photos of Hale because you can see him in action. Hale was a wildly successful dreamer and schemer who numerous times was able to talk the rich and famous out of money to advance knowledge. He did this not only for astronomy, but in many other areas as well.

Make No Small Plans
Dream No Small Dreams

If you missed the recent re-broadcast of The Journey to Palomar on PBS, you can catch it on Hulu and learn more about this amazing man.

Friday, June 24, 2011

Astrophoto Friday

It is the return of Astrophoto Friday!

The image is of the globular star cluster known as NGC 288.

This image was captured using the wide-angle 48-inch Samuel Oschin Schmidt Telescope. This is a crop of a much larger image. It was taken as a part of the Palomar Transient Factory (PTF) survey and comes to us from Jason Surace and the PTF collaboration.

Wednesday, June 22, 2011

Reminder: The Journey to Palomar on PBS

Consider yourself reminded that The Journey to Palomar airs on many PBS stations tonight (June 22nd). Be sure to check your local listings and check out the trailer below:

The trailer was made for the first airing of the documentary, which is why it says "November 10th" at the end. Feel free to ignore that.

Tuesday, June 21, 2011

Palomar in a Vintage Escondido Travel Brochure

PALM-3000, the world's best adaptive optics instrument, is currently on the Hale Telescope, but instead of talking about that, I am going to share a bit of Palomar history.

Below are scans from a 1951 brochure put out by the Escondido Chamber of Commerce.

You are going to want to click on the image below to view the inside of the brochure which was written by David O. Woodbury. Some of you may recall that Woodbury was the author The Glass Giant of Palomar, one of the first books to tell the story of the 200-inch telescope. The details described inside are pretty much spot on, but the one odd thing is the diagram that shows off the path of light through the telescope. There are several places where light can be focused and the illustration shows the just one of the three -- coudé focus.

The back cover of the brochure shows the location of Escondido and how to get to the observatory via The Highway to the Stars.

Alas, The Highway to the Stars signs that once marked the roadway are now long gone. The observatory now sells a reproduction of the sign on one of our t-shirts, but here is how they looked:

Saturday, June 18, 2011

The Journey to Palomar Returns to PBS this Week

I am happy to report that The Journey to Palomar, a documentary about George Ellery Hale and the building of the 200-inch telescope, will again be shown on PBS. It is a moving and inspirational story that is not to be missed.

Follow this link to check your local listings.

A short clip is posted below.

Friday, June 17, 2011

Palomar Mountain State Park to Close

You may have heard that Palomar Mountain State Park is on the list of 70 California State Parks that are slated to be closed. A lot of people have been asking me how this will affect Palomar Observatory. People have even been asking me if this meant that the observatory will be closing.

Palomar Observatory is privately owned by the California Institute of Technology, a private research university located in Pasadena. Palomar Mountain State Park is owned by the State of California. A closure of the park will have no direct affect on the observatory (although I suspect we will have fewer campers coming our way as tourists).

Palomar Observatory is not closing. We have a lot of work still to do.

Saturday, June 11, 2011

Looking Ahead

Earlier this month the 2011B observing schedule for the 200-inch Hale Telescope was announced. The astronomers who applied for time in early April finally found out if and when they will be coming to Palomar from August through January.

I thought that the readers of Palomar Skies might like summary of the projects coming our way this fall, so here goes.

Photo by Iair Arcavi.

Transients are all the rage and 13 nights, spread out across the months, will be devoted to following up on objects discovered with the Palomar Transient Factory survey. An additional four nights will be devoted to doing similar work, but for transients discovered via the Catalina Real-Time Transient Survey. Both of these programs will primarily use our visible light spectrograph to identify the type of transients discovered. One other night will specifically devoted to a particular type of supernova known as a Type Ia.

The other big item on the agenda for 2011B is the study of exoplanets. Some of this is follow-up work from the Kepler mission. 14 nights are devoted to various studies on Kepler exoplanets or their host stars. Much of this is visible or near infrared spectroscopy, but some of it also makes use of our newly souped-up adaptive optics system known as PALM-3000. This high-resolution imaging system will be used 12 nights to study and hunt for exoplanets and planet-forming disks of debris located around young stars. Using instruments other than the AO system, two nights will be used to study some of these disks discovered by the WISE mission and another two to study some “hot Jupiters” as they are seen to transit their host stars. All together that comes to 30 nights of exoplanets in 2011B or 1/6th of the telescope time.

Speaking of planets and things that orbit a star, worlds of our own solar system are a subject of study too. This includes studies of asteroids (8 nights), the Galilean moons of Jupiter (1), the irregular satellites of the outer planets (2), the atmosphere of Uranus (1), and the frozen world located beyond Neptune in the Kuiper Belt (2).

Looking a little further out, 12 nights will be devoted to studying brown dwarfs, so called “failed stars” – objects that are more massive than a planet but not massive enough to sustain nuclear fusion the way that stars do. Many of the objects to be observed were first discovered by the WISE mission.

Lots of stellar astrophysics will be going on as our astronomers study star formation (3), young stars and protostars (4), young variable stars, novae (4), white dwarfs (2), x-ray binary systems (1). The presence of dark matter in our own galaxy will be mapped via studies of the motions of RR Lyrae type variable stars that are part of the Pisces tidal stream (3).

Photo by Iair Arcavi.

Looking beyond our galaxy is still a big part of science at Palomar. In fact, aside from engineering time, it comprises the rest of the time on the schedule. Massive stars and the chemistry of the stars in M31 (aka the Andromeda Galaxy), our nearest big galaxy, will be the subject of study for 8 nights. Included on the list are blue compact dwarf galaxies (2), massive elliptical galaxies (5), hyperluminous galaxies (1), low-luminosity star-forming galaxies (5), galaxies known as Lyman-alpha emitters (7), luminous infrared galaxies (7), and galaxy clusters (6). Five nights will be directed toward the evolution of galaxies and six nights will be devoted toward using the Cosmic Web Imager instrument to map out the presence of gas located between galaxies.

Supermassive black holes, which lie at the core of quasars and various galaxies with active galactic nuclei are to be studied for six nights, while quasars themselves are studied another seven nights. The environment in and around another type of active galaxy – radio galaxies— is to be studied for five nights.

It takes time to keep the telescope & its instrumentation in tip-top shape. Seven nights will be lost because we will be re-aluminizing the 200-inch mirror in October. An additional twelve nights will be spent on engineering various scientific cameras, mostly related to our new PALM-3000 adaptive optics system. Two of those nights will be a demonstration of a new instrument known as ARCONS – the ARray Camera for Optical to Near-IR Spectrophotometry. It is likely that there will be science observations on a good fraction of these “engineering” nights.

Finally, we will be closed to astronomy and engineering December 24 & 25 for our only two holidays of the year.

There is the summary of what we will be looking at from August through January. Hopefully I didn't miss anything.

Friday, June 10, 2011

Press Coverage for Supernova Story & A Pretty Pic

The supernova story is making the rounds. In addition to reading about it here on Palomar Skies it has been picked up by, the LA Times, Physorg, National Geographic, The Republic, Daily India, the San Diego Union Tribune, Universe Today, IO9, HPWREN, Sky & Telescope and others.

Now to make your Friday more special, check out this photo by Caltech astronomer Evan Kirby:

It is a beautiful shot of the "summer" Milky Way taken from next to the dome of the Hale Telescope. For more on what is shown here be sure to check out this posting over at the Bamboo Shoots Photography Blog. There you will find a fully labeled version and an explanation of some of the cool objects in the picture.

Thursday, June 9, 2011

Hale Telescope Webcam is Back!

It has been a tough spring for the webcam in the dome of the 200-inch Hale Telescope, but as summer approaches I am happy to announce that it is back on line.

I made a slight adjustment on the camera's focus this morning and captured this shot of me with the Big Eye. I will try not to block the view from now on.

Wednesday, June 8, 2011

Press Release: Caltech-led Astronomers Find a New Class of Stellar Explosions

Below is a press release that was issued today about some of the science behind the Palomar Transient Factory survey.

PASADENA, Calif.—They're bright and blue—and a bit strange. They're a new type of stellar explosion that was recently discovered by a team of astronomers led by the California Institute of Technology (Caltech). Among the most luminous in the cosmos, these new kinds of supernovae could help researchers better understand star formation, distant galaxies, and what the early universe might have been like.

"We're learning about a whole new class of supernovae that wasn't known before," says Robert Quimby, a Caltech postdoctoral scholar and the lead author on a paper to be published in the June 9 issue of the journal Nature. In addition to finding four explosions of this type, the team also discovered that two previously known supernovae, whose identities had baffled astronomers, also belonged to this new class.

Quimby first made headlines in 2007 when—as a graduate student at the University of Texas, Austin—he discovered what was then the brightest supernova ever found: 100 billion times brighter than the sun and 10 times brighter than most other supernovae. Dubbed 2005ap, it was also a little odd. For one thing, its spectrum—the chemical fingerprint that tells astronomers what the supernova is made of, how far away it is, and what happened when it blew up—was unlike any seen before. It also showed no signs of hydrogen, which is commonly found in most supernovae.

At around the same time, astronomers using the Hubble Space Telescope discovered a mysterious supernova called SCP 06F6. This supernova also had an odd spectrum, though there was nothing that indicated this cosmic blast was similar to 2005ap.

The 1.2-meter Samuel Oschin Telescope at Palomar Observatory that was used to discover four supernovae of a new class. Inset: one of the newly discovered supernovae, PTF09cnd.
[Credit: Caltech/Scott Kardel/Robert Quimby/modified from Nature]

Shri Kulkarni, Caltech's John D. and Catherine T. MacArthur Professor of Astronomy and Planetary Science and a coauthor on the paper, recruited Quimby to become a founding member of the Palomar Transient Factory (PTF). The PTF is a project that scans the skies for flashes of light that weren't there before—flashes that signal objects called transients, many of which are supernovae. As part of the PTF, Quimby and his colleagues used the 1.2-meter Samuel Oschin Telescope at Palomar Observatory to discover four new supernovae. After taking spectra with the 10-meter Keck telescopes in Hawaii, the 5.1-meter telescope at Palomar, and the 4.2-meter William Herschel Telescope in the Canary Islands, the astronomers discovered that all four objects had an unusual spectral signature.

Quimby then realized that if you slightly shifted the spectrum of 2005ap—the supernova he had found a couple of years earlier—it looked a lot like these four new objects. The team then plotted all the spectra together. "Boom—it was a perfect match," he recalls.

The astronomers soon determined that shifting the spectrum of SCP 06F6 similarly aligned it with the others. In the end, it turned out that all six supernovae are siblings, and that they all have spectra that are very blue—with the brightest wavelengths shining in the ultraviolet.

According to Quimby, the two mysterious supernovae—2005ap and SCP 06F6—had looked different from one another because 2005ap was 3 billion light-years away while SCP 06F6 was 8 billion light-years away. More distant supernovae have a stronger cosmological redshift, a phenomenon in which the expanding universe stretches the wavelength of the emitted light, shifting supernovae spectra toward the red end.

The four new discoveries, which had features similar to 2005ap and SCP 06F6, were at an intermediate distance, providing the missing link that connected the two previously unexplained supernovae. "That's what was most striking about this—that this was all one unified class," says Mansi Kasliwal, a Caltech graduate student and coauthor on the Nature paper.

Even though astronomers now know these supernovae are related, no one knows much else. "We have a whole new class of objects that can't be explained by any of the models we've seen before," Quimby says. What we do know about them is that they are bright and hot—10,000 to 20,000 degrees Kelvin; that they are expanding rapidly at 10,000 kilometers per second; that they lack hydrogen; and that they take about 50 days to fade away—much longer than most supernovae, whose luminosity is often powered by radioactive decay. So there must be some other mechanism that's making them so bright.

The four supernovae discovered by the Palomar Transient Factory. Left: before explosion. Right: after explosion. From top to bottom, the supernovae are PTF09atu, PTF09cnd, PTF09cwl, and PTF10cwr.
[Credit: Caltech/Robert Quimby/Nature]

One possible model that would create an explosion with these properties involves a pulsating star about 90 to 130 times the mass of the sun. The pulsations blow off hydrogen-free shells, and when the star exhausts its fuel and explodes as a supernova, the blast heats up those shells to the observed temperatures and luminosities.

A second model requires a star that explodes as a supernova but leaves behind what's called a magnetar, a rapidly spinning dense object with a strong magnetic field. The rotating magnetic field slows the magnetar down as it interacts with the sea of charged particles that fills space, releasing energy. The energy heats the material that was previously blown off during the supernova explosion and can naturally explain the brightness of these events.

The newly discovered supernovae live in dim, small collections of a few billion stars called dwarf galaxies. (Our own Milky Way has 200–400 billion stars.) The supernovae, which are almost a hundred times brighter than their host galaxies, illuminate their environments like distant street lamps lighting up dark roads. They work as a kind of backlight, enabling astronomers to measure the spectrum of the interstellar gas that fills the dwarf galaxies in which the supernovae reside, and revealing each galaxy's composition. Once an observed supernova fades a couple of months later, astronomers can directly study the dwarf galaxy—which would have remained undetected if it weren't for the supernova.

These supernovae could also reveal what ancient stars might have been like, since they most likely originate from stars around a hundred times more massive than the sun—stars that would have been very similar to the first stars in the universe.

“It is really amazing how rich the night sky continues to be," Kulkarni says. "In addition to supernovae, the Palomar Transient Factory is making great advances in stellar astronomy as well.”

In addition to Quimby, Kasliwal, and Kulkarni, 24 other authors—11 of whom are from Caltech—contributed to the work described in the Nature paper, "A new class of hydrogen-poor super-luminous stellar explosions." This research was supported by the National Science Foundation, the United States-Israel Binational Science Foundations, the Israeli Science Foundation, the Department of Energy, the Gordon & Betty Moore foundation, Gary and Cynthia Bengier, the Richard and Rhoda Goldman Fund, and the Royal Society. The Palomar Transient Factory is a collaboration between Caltech, Columbia University, Las Cumbres Observatory Global Telescope, Lawrence Berkeley Laboratory, UC Berkeley, University of Oxford, and the Weizmann Institute of Science (Israel).

# # #

Written by Marcus Woo

Friday, June 3, 2011

Amateur Astronomers Can Help PTF Study Supernova in M51

Earlier today I reported the discovery of a new Type II Supernova in the Whirlpool Galaxy (M51). The astronomers behind the Palomar Transient Factory have initiated a world-wide effort to collect amateur imagery of M51 taken from May 30 - June 2 to best constrain the explosion time of the massive star.

The supernova is known as "PTF 11eon" to the PTF team, but as SN2011dh to the larger world. A finder chart for it is shown below.

Click to enlarge the image.

Any amateur astronomers who have raw images of M51 taken between May 30 and June 2 are encouraged to contact the PTF team at this address:

For more on the supernova, check out this article from Sky & Telescope or this one from Universe Today.

Breaking News - A Supernova in M51

Astronomers with the Palomar Transient Factory are reporting the discovery of a supernova in the Whirlpool Galaxy (M51).

It has been classified as a Type II supernova, which means that it is the result of the collapse and explosion of a massive star. The classification was performed using the Keck I telescope in Hawai'i. The magnitude of the star was estimated at 13.5, which makes it bright enough for amateur astronomers to see and image. It should be noted in the discovery report that the "exact magnitude uncertain due to saturation" - meaning that the supernova was too bright for astronomers to measure. Of course they were using one of the largest telescopes on the planet.

I am checking to see if there will be images to post, but in the meantime here is a shot of M51 taken well over a year ago by Palomar's 48-inch Samuel Oschin Telescope as a part of the Palomar Transient Factory Survey:

I am sure that there will be more news on this in the coming days and weeks, so stay tuned.