To recover from the Bobcat Fire and the loss of revenue from the pandemic, Mount Wilson Observatory needs your help! If you can, please make a donation or join with a supporting membership. Our largely volunteer organization receives no regular support from any institutions or government, so any help we get from the public during this tough year is greatly appreciated!!! Thanks for supporting science, education, and the preservation of this world-class historic site.
One of a series of online presentations from Palomar Observatory, Thompson’s 2/06/21 talk highlights many of the innovations and discoveries in astronomy made at Mount Wilson Observatory. In the 1 hour 47 minute lecture with slides, he goes into some depth, explaining the astrophysics behind some of the more important work done on the mountain, past and present. While many are familiar with Hubble and Shapley’s contributions to modern cosmology, there were many other less well known discoveries made here that changed the course of astronomy.
Click here to read the December issue of our newsletter and get a quick update on our status during the pandemic and post-Botcat Fire era.
The feature article is on the fire, which lingered in the canyons below Mount Wilson right up until our first major storm put an end to it with a blanket of snow on the 27th and 28th of December. It burned for more than three months, after starting on Labor Day weekend. The second article is on Betelgeuse and Baade. Betelgeuse is the first star ever measured (other than the Sun), a remarkable achievement made at the Observatory 100 years ago this December. (To read the first article about this milestone in astronomy, see last December’s issue of Reflections here. The follow-up article on how Walter Adams, the second director of the Observatory, figured out how to measure distances to thousands of stars, a prerequisite to determining their sizes can be found here.) Betelgeuse, a red supergiant, is on the shortlist of “nearby” stars that are expected to go supernova in the next 100,000 years. Walter Baade, one of the Observatory’s more famous astronomers, observed his first supernova one hundred years ago from his native Germany. He and Fritz Zwicky at Mount Wilson brought supernova research into the modern era,
A letter from our Chairman of the Board of Trustees, Sam Hale, updates us on the Observatory’s status and progress in a difficult year.
We know that many of our supporters are struggling with the pandemic and economic downturn this year, so we are especially thankful to all who have helped us “weather the storm.” All who donated from July 1 to December 1 are honored in the newsletter. All these donations, large and small, have helped make up for some of our shortfall in revenue this year. Those who joined us as members are also deeply appreciated and are listed on our Website. We thank them all for supporting science, education, and the historic preservation of this remarkable Observatory high above Los Angeles–where we discovered our place in the Universe!
For the first half of the 20th Century, Mount Wilson was the most famous observatory in the world. The biggest telescopes were here, and their new designs were changing the way astronomy was done. Among the many discoveries made on the mountain, a few revolutionized our understanding of our place in the Universe. Here, during WWI, Harlow Shapley measured the size of the Milky Way Galaxy for the first time and located our position in it, far from the center. Then, in 1924, Edwin Hubble proved that the mysterious spiral nebulae, which astronomers had speculated about for decades, were in fact distant galaxies similar to our own. Then Hubble teamed up with Milton Humason and confirmed that this immense Universe was expanding. Space itself was getting bigger. This finding, when run backwards in time, led a few decades later to the Big Bang Theory. Mount Wilson is where modern observational cosmology began. It holds a unique place in humanity’s search for our most distant origins. Today, our original solar and nighttime telescopes, the world’s largest for two generations of astronomers, have been joined by the new CHARA array, which has the highest resolution of any optical or infrared system ever built, achieving unprecedented views of the stars.
A publicity photo of astronomer Edwin Hubble guiding Mount Wilson’s 100-inch Telescope in 1924, shortly after he proved the existence of distant galaxies. Photo: Carnegie Observatories/ Huntington Library.
Join the Observatory as a member! By doing so, you get a number of benefits and you help us renew this historic mountaintop, so that it may inspire well into the future. We aim to build a larger community to keep us moving forward with educational STEM programs, undergraduate research, public outreach, ongoing scientific research, and restoration of our 116-year-old observatory.
Please consider becoming a member in 2021, to help us through this year. If you can. Sign up for the individual membership, family membership, or a higher level, all named after one of our famous astronomers. Sign up is easy. Click here to go to our membership page.
Called Sunstar, it is an array of six prisms which take incoming sunlight and refract it, bending the light and spreading it into a spectrum–all the colors of the rainbow. It is mounted near the top of the Observatory’s 150-foot Solar Telescope Tower. With motion controls, it can be remotely directed to project the spectrum to a specific point in the Los Angeles basin. An observer below will see an intense point of light in a single wavelength, shining like a brilliant jewel from the ridgeline of Mount Wilson, 5800 feet above in the San Gabriel Mountains. The prisms can be moved to change the color of light an observer sees, or the observer can walk in one direction or another to change the color. In this case, the observer is actually walking across a giant spectrum some 250 yards long. While still very bright, at the great distances involved, it is perfectly safe to look at a single wavelength of sunlight. For more information and a schedule, go to our Sunstar page.
The Observatory’s founder, George Ellery Hale, built four telescopes, each one in succession becoming the largest in the world. Here they are shown to the same scale. His first was the 40-inch refractor at Yerkes (in Wisconsin) on the left, but then he began building the more revolutionary–and more compact–reflector telescopes, using a large mirror instead of a lens. His next two are on Mount Wilson, the 60-inch and the 100-inch. (While not quite as grand as his last, these two had the light-gathering power for astronomers to discover our place in the expanding Universe.) His fourth, the 200-inch Hale Telescope at Palomar, is represented on the right by one of Russell Porter’s famous cutaway drawings. This image has been reversed and extended on the left side for a better comparison of the relative sizes of the full domes. Hale’s telescopes were the biggest from 1897, when Yerkes opened, to 1993, when the Keck telescope in Hawaii was completed–a span of 96 years. To see these drawings enlarged, click here. Drawing credits: University of Chicago/Yerkes Observatory, Carnegie Observatories, Palomar Observatory/Caltech.