Thursday, December 31, 2009

Palomar in Science Fiction - Kronos

I just had the opportunity to watch the 1957 sci-fi movie Kronos and was pleased to learn that it is another of the many films that have featured Palomar Observatory.

In the movie the astronomers, working at LabCentral, are tracking a 4-mile wide "asteroid" known as M47 (not to be confused with the star cluster of the same name), which is apparently headed directly for, you guessed it, Earth.

Early on we see LabCentral from the outside, the dome look a bit like the 200-inch at Palomar, but not too much, as we are lacking the other buildings, the security guard station, etc.

Further observations and analysis determines that "asteroid" M47 will hit near New York and we get to see Palomar's 200-inch Hale Telescope.

Of course in the film it isn't Palomar, its LabCentral. Palomar does get named though as astronomer Dr. Gaskell mentions that he needs to phone professor Winter at Palomar to get verification of the position of M47.

The gang at LabCentral launch 3 nuclear missiles to destroy M47 in our upper atmosphere (that might even be worse than letting it hit), but alas the mysterious object absorbs the nuclear energy and lands in the Pacific Ocean off of the coast of Mexico (no where near New York).

What emerges is a giant, um robot, dubbed Kronos.

The still image doesn't do Kronos justice. Check out the trailer for the film embedded below and you'll see what I mean.

Yes, the movie is cheesy, but it is fun and surprisingly good in places.

p.s. This is my 500th post on this blog and I am wishing a Happy New Year to all the readers of Palomar Skies!

Monday, December 28, 2009

Palomar History Photo of the Week - December 28, 2009

2009, the International Year of Astronomy (IYA), is almost over. It has been a year-long celebration of the 400th anniversary of Galileo's first astronomical observations.

This week's Palomar History Photo of the Week celebrates the advances in telescopes with an IYA nod from Palomar to Galileo and Isaac Newton.

The photo shows one of the 200-inch opticians on the left looking through a replica of Galileo's telescope. The telescope is balanced on the shoulder of chief optician Marcus Brown. Behind them stands the completed 200-inch mirror in the optical shop at Caltech. In the mirror's center hole is an exact size replica (in artwork only) of Isaac Newton's first reflecting telescope.

The photo was likely taken during the fall of 1947. I would like to thank the Brown Family for their donation of this photo and other items to Palomar Observatory earlier this year.

Saturday, December 26, 2009

This and That

Palomar Observatory is now back on its regular winter hours and open to visitors 9 am - 3 pm daily.

Astrobiology Magazine has named the discovery of exoplanet VB 10b, found using Palomar's Hale Telescope, as one of their Astrobiology Top 10 for the year.

Remember the 365 Days of Astronomy podcasts are continuing for 2010, but there still many open dates, even for the month of January.

Miller McCune magazine published an article on the dark-skies movement in Borrego Springs, CA: Stary, Stary Skies California desert town takes back the night, wins rare "Dark Sky" award.

Wednesday, December 23, 2009

Observatory Closed December 24 & 25

Remember Palomar Observatory is closed to the public December 24 & 25.

Monday, December 21, 2009

Palomar History Photo of the Week - December 21, 2009

The Winter Solstice occurs at 9:47 a.m. PST today here in the Northern Hemisphere, so this week's Palomar History Photo of the Week is a winter scene.

Here is a photo of the 200-inch telescope's dome taken during snow showers back in January 1938.

Lots of people like to visit Palomar around Christmas looking for snow. We do not have any on the ground now and there isn't any in the current forecast. As a reminder the observatory is closed December 24 & 25.

Sunday, December 20, 2009

The Known Universe

The American Museum of Natural History astronomer Ben R. Oppenheimer (a member of the team that found the companion to the star Alcor) is part of the group that produced The Known Universe - a short film produced from real astronomical data that takes the viewer on an amazing trip.

From Dr. Oppenheimer's web site:

Every mountain, planet, satellite, star, galaxy, quasar and our cosmic horizon are represented accurately in both size and position relative to each other, based on our best scientific knowledge to date. No interpolations have been made, and only objects that have actually been observed are included. As a result, you will see vast regions of the universe where we have not yet been able to map the locations of particular types of objects, for various scientific reasons. These gaps are akin to the regions labeled 'terra incognita' in old globes and maps, before people had fully documented the geography of the world. This visualization starts from the mountains of Tibet and takes you swirling though our database out to the furthest reaches of the universe that are observable. As we travel away from Earth, the distance from home is represented in the length of time that light takes to travel the same distance.

The film is based on the Digital Universe Atlas, an on-going project of the American Museum of Natural History and the Hayden Planetarium, which consists of the world's most complete and scientifically accurate four-dimensional map of the universe. This visualization, while demonstrating some of the wealth of the Digital Universe Atlas, features only a fraction of the database.

Wednesday, December 16, 2009

Palomar Find Makes Discovery News Top 10 of the Decade

Discovery News has put out their list of the Top 10 Discoveries of the Decade and their list of Top 10 Space Discoveries of the Decade.

On both lists is the 2005 discovery of the world known as Eris. Knowledge of the existence of Eris, named after the Greek goddess of discord, helped to push Pluto out of the planetary roll call. In 2006, the International Astronomical Union officially proclaimed both Pluto and Eris to be part of a new, non-planet, classification known as "dwarf planets."

The discovery was made using the Palomar Observatory's 48-inch Samuel Oschin Telescope by the team of Mike Brown (Caltech), Chad Trujillo (Gemini Observatory) and David Rabinowitz (Yale).

The discovery was made as a part of survey of the outer solar system using the Palomar QUEST camera and the Samuel Oschin Telescope at the Palomar Observatory.


HPWREN Helps Palomar Make the List of the Decade's Top 10 Discoveries

See also Ten Science Discoveries That Changed Our Decade and Top ten science stories of the decade from MSNBC.

Monday, December 14, 2009

Palomar History Photo of the Week - December 14, 2009

The men who built the dome of the 200-inch Hale Telescope

Group photos are great. This one comes from the collection of Earnest A. Whichelo, who back in the day was the manager of Consolidated Western Steel. CWS was the main contractor who built the dome for the 200-inch telescope. From the looks of the dome behind the group I am pretty sure that the photo was taken in 1938. Click on the photo and you can easily see each and every face of the crew that did the work.

The photo comes from a collection of photos donated to the observatory by Cindy Johnson, daughter of Earnest Whichelo. I posted another photo from this collection in a post over a year ago. Let me quote now what I said then:

We thank Ms. Johnson and the others over the years that have returned parts of Palomar Observatory's history back to us. Each photo is a treasure and reminds us of the tremendous work done by the people who made the Hale Telescope what it is.

Recently the observatory has been very fortunate as a many individuals have been coming forth with donations of photos and other items from our past. We are in the process of scanning and will share more of these here on the blog and eventually on the observatory's main website and out for people to see when the visit the observatory in person.

Saturday, December 12, 2009

Outdoor Lighting at Night

As I am sure most of my readers know, the issue of light pollution and good outdoor lighting is very important to Palomar Observatory.

Recently I had the opportunity to attend a demonstration of streetlights by Visionaire Lighting. They showed off a variety of products including an amber LED streetlight.

As you can see the light from the amber LED looks a lot like the light from a low-pressure sodium light. Looks can be deceiving The key to understanding how such a lamp might affect astronomy is to have a more detailed look at the mix of colors that it is composed of. This is done by breaking the light into its component colors - its spectrum. Here is what the spectrum looks like for the amber LED:

The light source is on the right and the spectrum is on the left. Compare the spectrum of the amber LED with a white LED streetlight (below):

The white light offers up a full rainbow of colors (one of the reasons some people like it so much), yet it presents some problems for astronomy. Partly, it is rich in blue light which contributes to Rayleigh scattering, the phenomenon that makes the sky blue in the daytime. Blue light from streetlights disproportionally makes the sky brighter at night too.

One way to limit the amount of blue in the light is to use a narrow band light source such as low-pressure sodium or perhaps the amber LED. Another way that is not as effective for astronomy is to use a light of a low color temperature. Have a look at the two LED lights below and you'll notice that the higher color temperature lamp on the left looks blue and the lower temperature one on the right looks yellow.

The yellowish light on the right is made up of a different mix of light. It has less blue in it. While this is not as attractive astronomically as a narrow-band light source, the lower color temperature lamp will produce less skyglow than the higher temperature one (if all other things like level of illumination and light fixtures are equal).

But even limiting the color temperature does not help enough to make a streetlight attractive to astronomers. A lower color temperature light source still has a broad range of colors that fills up the spectrum. This full spectrum is a problem because it doesn't give astronomers any "window" to look through. The graphic below gives an idea of the concept:

So what is the point of all this? The observatory's position on outdoor lighting is still the same.

Cities, businesses and homeowners should:

  • Use only as much light as is needed for a task. Do not over-light.
  • Shield lights to prevent direct upward illumination.
  • Turn off lights when they are not needed.
  • Use low-pressure sodium lights to the greatest degree possible.

  • Anyone that follows the first three points will save money and help to preserve dark skies. To the final point it may be time to modify it to read "Use low-pressure sodium or other monochromatic lights to the greatest degree possible." We may eventually have streetlights that can mimic the astronomical advantages of low-pressure sodium lights. Visionaire's amber LED is the only one that I have had the chance to see in person. There are other companies and other ideas that might prove to be good choices for astronomy.

    Thanks to Visionaire for showing off some of their products (more later) to the San Diego chapter of the International Dark-sky Association and to Oceanside Photo & Telescope for hosting the lighting demonstration in their parking lot.

    Thursday, December 10, 2009

    A Companion for Alcor

    The Big Dipper, isn't a constellation (technically it is an asterism), but it is one of the most famous groups of stars in the sky. Nestled within the handle of the Dipper are some famous stars. The middle star of the handle is called Mizar. Next to Mizar is another star that has often been used to test visual acuity--Alcor.

    Can you spot the Big Dipper with Mizar and Alcor in this photo taken from the catwalk of the Hale Telescope? Click to embiggen and hopefully the stars will be easy to spot.

    The close proximity of Alcor to Mizar make the stars great targets for casual evening stargazing. Pointing a small telescope at the pair gives a nice surprise as Mizar is revealed to be not one star, but two. Further spectroscopic studies have revealed that Mizar is made up of more stars that are unseen because they too close to each other to be resolved as individual stars. But what of Alcor?

    You may remember Project 1640, one of new instruments commissioned for the 200-inch telescope lat year. Project 1640 makes use of the Hale Telescope's adaptive optics system, which gives the Hale a view almost equal to what can be obtained from in space. The instrument also has the ability to block out the light of a star, allowing faint objects located next to a star to be seen. This technique should soon be revealing previously unseen exoplanets. The Hale, armed with Project 1640, was pointed at Alcor earlier this year and found that it isn't a single star. Alcor has a small stellar companion that hadn't been seen before.

    What is it like? The companion, Alcor B, is a small, dim red dwarf star about one fourth the mass of our Sun.

    Caption: Alcor is a star in the handle of the Big Dipper. This discovery image shows Alcor B, marked with the green arrow in the inset. Alcor B is a newly found red dwarf companion of Alcor. Project 1640 astronomers discovered the faint star by blocking out almost all of Alcor's light with a coronagraphic mask, the darker circular region in the middle of the image. Although the vast majority of Alcor’s light has been blocked out, a residual halo of speckles remains because of minute imperfections in the camera’s optics. The actual diameter of either of the stars far smaller than a pixel in this image. This residual glare is what makes finding faint companions of bright stars difficult.

    Credit: Project 1640, American Museum of Natural History, Digital Universe Atlas

    For those who are so inclined, here is a link to where you can find the scientific paper on the discovery. The press release is announcing the discovery is below. Note the nod to Galileo in both the press release and the scientific paper, making this a nice discovery for the International Year of Astronomy.

    A Faint Star Orbiting the Big Dipper’s Alcor discovered

    Project 1640 Uses a Novel Technique with Ties to Galileo to See the Unknown

    Next time you spy the Big Dipper, keep in mind that there is another star invisibly (at least to the unaided eye) contributing to this constellation. According to a new paper published in The Astrophysical Journal, one of the stars that makes the bend in the ladle’s handle, Alcor, has a smaller red dwarf companion. Newly discovered Alcor B orbits its larger sibling, caught in the act with an innovative technique called “common parallactic motion” by members of Project 1640, an international collaborative team that includes astrophysicists at the American Museum of Natural History, the University of Cambridge’s Institute of Astronomy, the California Institute of Technology, and NASA’s Jet Propulsion Laboratory.

    “We used a brand new technique for determining that an object orbits a nearby star, a technique that’s a nice nod to Galileo,” says Ben R. Oppenheimer, Curator and Professor in the Department of Astrophysics at the Museum. “Galileo showed tremendous foresight. Four hundred years ago, he realized that if Copernicus was right—that the Earth orbits the Sun—they could show it by observing the “parallactic motion” of the nearest stars. Incredibly, Galileo tried to use Alcor to see it but didn’t have the necessary precision.” If Galileo had been able to see change over time in Alcor’s position, he would have had conclusive evidence that Copernicus was right. “Parallactic motion” is the way nearby stars appear to move in an annual, repeatable pattern relative to much more distant stars, simply because the observer on Earth is circling the Sun and seeing these stars from different places over the year.

    Alcor is a relatively young star twice the mass of the Sun. Stars this massive are relatively rare (less than a few percent of all stars), short-lived, and bright. Alcor and its cousins in the Big Dipper formed from the same cloud of matter about 500 million years ago, something unusual for a constellation since most of these patterns in the sky are composed of unrelated stars. Alcor shares a position in the Big Dipper with another star, Mizar. In fact, both stars were used as a common test of eyesight—being able to distinguish “the rider from the horse”—among ancient people. One of Galileo’s colleagues observed that Mizar itself is actually a double, the first binary star system resolved by a telescope. Many years later, the two components Mizar A and B were themselves determined each to be tightly orbiting binaries, altogether forming a quadruple system.

    Now, Alcor, which is near the four stars of the Mizar system, also has a companion. This March, members of Project 1640 attached their coronagraph and adaptive optics to the 200-inch Hale Telescope at the Palomar Observatory in California and pointed to Alcor. “Right away I spotted a faint point of light next to the star,” says Neil Zimmerman, a graduate student at Columbia University who is doing his PhD dissertation at the Museum. “No one had reported this object before, and it was very close to Alcor, so we realized it was probably an unknown companion star.”

    The team retuned a few months later and re-imaged the star, hoping to prove that the two stars are companions by mapping the tiny movement of both in relation to very distant background stars as the Earth moves around the Sun, parallactic motion. If the proposed companion were just a background star, it wouldn’t move along with Alcor.

    “We didn’t have to wait a whole year to get the results,” says Oppenheimer. “We went back 103 days later and found the companion had the same motion as Alcor. Our technique is powerful and much faster than the usual way of confirming that objects in the sky are physically related.” The more typical method involves observing the pair of objects over much longer periods of time, even years, to show that the two are moving through space together.

    Alcor and its newly found, smaller companion, Alcor B, are both about 80 light-years away and orbit each other every 90 years or more. Over one year, the Alcor pair moves in an ellipse on the sky about 0.08 arc seconds in width because of the Earth’s orbit around the Sun. This amount of motion, 0.08 arcsec, is about 1000 times smaller than the eye can discern, and a fraction of this motion was easily measured by the Project 1640 scientists.

    The team was also able to determine the color, brightness and even rough composition of Alcor B because the novel method of observation that Project 1640 uses records images at many different colors simultaneously. The team determined that Alcor B is a common type of M-dwarf star or red dwarf that is about 250 times the mass of Jupiter, or roughly a quarter of the mass of our Sun. The companion is much smaller and cooler than Alcor A.

    “Red dwarfs are not commonly reported around the brighter higher mass type of star that Alcor is, but we have a hunch that they are actually fairly common,” says Oppenheimer. “This discovery shows that even the brightest and most familiar stars in the sky hold secrets we have yet to reveal.”

    The team plans to use parallactic motion again in the future. “We hope to use the same technique to check that other objects we find like exoplanets are truly bound to their host stars,” says Zimmerman. “In fact, we anticipate other research groups hunting for exoplanets will also use this technique to speed up the discovery process.”

    In addition to Zimmerman and Oppenheimer, authors include Anand Sivaramakrishnan and Douglas Brenner of the Astrophysics Department at the Museum; Sasha Hinkley, Lynne Hillenbrand, Charles Beichman, Justin Crepp, Antonin Bouchez and Richard Dekany of the California Institute of Technology; Ian Parry, David King, and Stephanie Hunt of the Institute of Astronomy at Cambridge University; Rémi Soummer of the Space Telescope Institute in Baltimore; and Gautam Vasisht, Rick Burruss, Michael Shao, Lewis Roberts, and Jennifer Roberts of the Jet Propulsion Laboratory at California Institute of Technology. Project 1640 is funded by the National Science Foundation.

    Wednesday, December 9, 2009

    WISE to Launch on Friday - moved to Monday

    Update: The launch of NASA’s Wide-field Infrared Survey Explorer
    mission is now rescheduled for Monday, Dec. 14, with a launch window of 6:09 to 6:23 a.m. PST

    An artist's rendering of WISE in orbit

    WISE, the Wide-Field Infrared Survey Explorer, is set to launch 6:09:33 a.m. PST Friday, December 11. Visit the link to their website to learn about this mid-infrared all-sky survey mission. If all goes well we will soon be learning a great many new things and, as in the case with the Spitzer Space Telescope, Palomar Observatory will be hosting many astronomers for follow-up observations.

    Good luck to the WISE team!

    Tuesday, December 8, 2009

    Palomar in Science Fiction - Destination Moon

    Destination Moon is a science fiction film from 1950 about the first trip to the Moon. While Palomar Observatory isn't shown in the film, it is mentioned. Have a look at this clip below:


    Yes, "The astronomers at Palomar say they can see you if they knew where to point the Big Eye."

    Nope, that isn't possible. Even using adaptive optics, which removes blurring caused by Earth's atmosphere, the best resolution we can get is about 200 meters per pixel. That's about what we got when we took a good look at the Moon last October as NASA's LCROSS probe crashed into the crater Cabeus:

    So if Spaceship Luna (or its shadow), was a few football fields long we would just be able to distinguish something with modern instrumentation. Alas, Spaceship Luna wasn't portrayed as being that big, so technical adviser Robert A. Heinlein didn't quite get it right. (Still, it is a cool film.)

    I bring this up because I am often asked if we look at the artifacts left on the Moon by the Apollo astronauts. As with Spaceship Luna, they are too small to be seen from Earth-based telescopes. That isn't true from the vantage point of the Lunar Reconnaissance Orbiter, which has returned images of the Apollo landing sites (for an example see High Noon at Tranquility Base).

    On that same vein I am also often asked if we look at the International Space Station. It turns out that the ISS is an easy target and amateur astronomers have taken some amazing images of it (for an example see the shots posted at

    Yet we don't take any time from our nights to look at the ISS. Why? The Hale Telescope was built not to look at the places and things we already know about. It was built to study the unknown.

    Super Collaboration Yields New Type of Supernova

    Last week a press release was issued about an amazing supernova discovery. Supernova 2007bi was a stellar explosion (the dot circled above) of a type never before seen. Follow the link to the press release to read about the death of this star, which was at least 200-times more massive than the Sun.

    It is well known that sometimes when you look for one thing you can also find something else. The astronomers at Berkeley’s Nearby Supernova Factory were part of a collaboration that allowed them to hunt for exploding stars (supernovae) using data that was collected for the Jet Propulsion Laboratory’s Near-Earth Asteroid Tracking (NEAT) program as they hunted for asteroids.

    This data for the NEAT survey and the Nearby Supernova Factory was collected using Palomar Observatory’s 48-inch Samuel Oschin Telescope. From 2003 - 2008 the telescope was operated robotically with data was beamed away from Palomar and eventually on to JPL & Berkeley via the High Performance Wireless Research and Education Network (HPWREN). This collaboration between Caltech’s Palomar Observatory, JPL, Berkeley and HPWREN has led to many discoveries. In the case of sn2007bi they were able to quickly alert observatories around the world and begin a long term study of this never-before-seen stellar explosion.

    Stay tuned as more of these supernovae are expected to be found by Palomar Transient Factory.

    Monday, December 7, 2009

    Palomar History Photo of the Week - December 7, 2009

    Blake Mitchell was one of the opticians who worked under the direction of Marcus Brown on the Palomar project after World War II. Blake, who is 86 year old now, recently donated to the observatory his collection of photographs from that time.

    For the very first picture from his collection I thought I would post his self portrait:

    That is Blake in the Optical Shop at Caltech. His reflection is posed with the 200-inch telescope's three secondary mirrors three spherical mirrors that were used to test the 200" telescope's convex hyperbolic secondary mirrors.

    Sunday, December 6, 2009

    Storms on the Way

    It looks like we will have an active week of weather bringing snow, rain, fog, wind and difficult travel conditions in and around Palomar. Be careful out there!

    Friday, December 4, 2009

    365 Days of Astronomy Podcasts to Continue in 2010

    I just got word that the 365 Days of Astronomy podcasts will continue in 2010, past the International Year of Astronomy.

    According to their website each of the 365 Days of Astronomy podcasts are heard by 5,000 - 10,000 listeners.

    Palomar Observatory's public outreach effort helped to financially support the program for 2009 and I personally contributed 7 podcasts. They are looking for more people to contribute for 2010. So if you have an idea and the equipment why not contact the and be a part of something cool.

    Wednesday, December 2, 2009

    Starlight versus our light

    The cover story in the December, 2009 issue of Physics Today:

    The article is Lighting and astronomy. It looks like you might need to be a subscriber to read it online, but if you get the chance, it is an excellent review of the history and problems that light pollution presents to astronomers.

    200" Mirror Cast 75 Years Ago Today

    75 years ago today, December 2, 1934, Corning Glass Works successfully cast the 200-inch mirror for what would become the Hale Telescope on Palomar Mountain.

    I have blogged about this before (see: December 2, 1934 and Pouring Glass: the Movie), but today I wanted to share a photo of the then still molten 200-inch mirror and its creator: physicist George V. McCauley of Corning Glass Works.

    It is an interesting photo because the molten glass is hot and glowing, revealing the pattern of the many hollow spots on its underside. Dr. McCauley, or "Mac" as he was called, later described what is shown in the above photo.

    "The changing appearance of the disk during this cooling period was fascinating and beautiful. When ladling was completed, the glass above the cores was hotter than the cores themselves and one saw the perfect pattern of the latter in darker contrast with the molten glass. As time passed and the surface glass cooled, while the cores - cooling less rapidly - became the more radiant and were seen as the highlights between the darker ribs of glass, the picture was so beautiful to look upon that it was with regret that it had to be sealed from sight within the two telescoping sections of the annealing kiln."

    His description was actually of the view just after they had poured the glass the the 120-inch mirror (now at Lick Observatory), but the Palomar mirror is also honeycombed and went through the same effect. Too bad there aren't any color photos of this.