Tag Archives: sun

NASA, Texas Astronomers Find First Multi-Planet System Around a Binary Star

FORT DAVIS, Texas — NASA’s Kepler mission has found the first multi-planet solar system orbiting a binary star, characterized in large part by University of Texas at Austin astronomers using two telescopes at the university’s McDonald Observatory in West Texas. The finding, which proves that whole planetary systems can form in a disk around a binary star, is published in today’s issue of the journal Science.

“It’s Tatooine, right?” said McDonald Observatory astronomer Michael Endl. “But this was not shown in Star Wars,” he said, referring to the periodic changes in the amount of daylight falling on a planet with two suns. Measurements of the star’s orbits showed that daylight on the planets would vary by a large margin over the 7.4-Earth-day period as the two stars completed their mutual orbits, each moving closer to, then farther from, the planets (which are themselves moving). (more…)

Read More

A Prime Seat to a Once-in-a-Lifetime Spectacle

Hosted by world-renowned astrophotographer Adam Block at the UA’s Mount Lemmon SkyCenter, a group of sky and astronomy enthusiasts watched Venus cross the sun from the highest vantage point in Southern Arizona.

On Nov. 24, 1639, in the tiny village of Much Hoole not far from Liverpool, England, a poor farmer’s son and self-taught astronomer affixed a sheet of paper in front of a makeshift telescope pointed at the sun and waited.

Thirty-five minutes before sunset, a dark, round spot appeared right next to the bright disc that was the sun’s face projected on the paper, and made Jeremiah Horrocks, only 20 years old at the time, the first known human to predict, observe and record a transit – the passage of a planet across the sun as seen from Earth.

Almost 373 years later, a group of sky enthusiasts is gathered beneath the dome of one of the University of Arizona’s observatories on Mount Lemmon just north of Tucson, Ariz. (more…)

Read More

Fossil Raindrop Impressions Imply Greenhouse Gases Loaded Early Atmosphere

In ancient Earth history, the sun burned as much as 30 percent dimmer than it does now. Theoretically that should have encased the planet in ice, but there is geologic evidence for rivers and ocean sediments between 2 billion and 4 billion years ago.

Scientists have speculated that temperatures warm enough to maintain liquid water were the result of a much thicker atmosphere, high concentrations of greenhouse gases or a combination of the two. (more…)

Read More

First Habitable-Zone super-Earth Discovered in Orbit Around a Sun-like Star

Washington, D.C. — NASA’s Kepler Mission has discovered the first super-Earth orbiting in the habitable zone of a star similar to the Sun. A team of researchers, including Carnegie’s Alan Boss, has discovered what could be a large, rocky planet with a surface temperature of about 72 degrees Fahrenheit, comparable to a comfortable spring day on Earth. This landmark finding will be published in The Astrophysical Journal.

The discovery team, led by William Borucki of the NASA Ames Research Center, used photometric data from the NASA Kepler space telescope, which monitors the brightness of 155,000 stars. Earth-size planets whose orbital planes are aligned such that they periodically pass in front of their stars result in tiny dimmings of their host star’s light–dimmings that can only be measured by a highly specialized space telescope like Kepler. (more…)

Read More

Scientists Prepare to Take First-Ever Picture of a Black Hole

*The Event Horizon Telescope is an Earth-sized virtual telescope powerful enough to see all the way to the center of our Milky Way, where a supermassive black hole will allow astrophysicists to put Einstein’s Theory of General Relativity to the test.*

Astronomers, physicists and scientists from related fields across the world will convene in Tucson, Ariz. on Jan. 18 to discuss an endeavor that only a few years ago would have been regarded as nothing less than outrageous.

The conference is organized by Dimitrios Psaltis, an associate professor of astrophysics at the University of Arizona’s Steward Observatory, and Dan Marrone, an assistant professor of astronomy at Steward Observatory. (more…)

Read More

In The Dragonfish’s Mouth: The Next Generation of Superstars to Stir Up Our Galaxy

TORONTO, ON – Three astronomers at the University of Toronto have found the most numerous batch of young, supermassive stars yet observed in our galaxy: hundreds of thousands of stars, including several hundreds of the most massive kind –blue stars dozens of times heavier than our Sun. The light these newborn stars emit is so intense it has pushed out and heated the gas that gave them birth, carving out a glowing hollow shell about a hundred light-years across.

These findings will be published in the December 20 issue of Astrophysical Journal Letters. For the researchers, the next step is already clear: “By studying these supermassive stars and the shell surrounding them, we hope to learn more about how energy is transmitted in such extreme environments,” says Mubdi Rahman, a PhD candidate in the Department of Astronomy & Astrophysics at the University of Toronto, who led the work with his supervisors, Professors Dae-Sik Moon and Christopher Matzner. (more…)

Read More

NASA Telescopes Help Solve Ancient Supernova Mystery

PASADENA, Calif. — A mystery that began nearly 2,000 years ago, when Chinese astronomers witnessed what would turn out to be an exploding star in the sky, has been solved. New infrared observations from NASA’s Spitzer Space Telescope and Wide-field Infrared Survey Explorer, or WISE, reveal how the first supernova ever recorded occurred and how its shattered remains ultimately spread out to great distances.

The findings show that the stellar explosion took place in a hollowed-out cavity, allowing material expelled by the star to travel much faster and farther than it would have otherwise. (more…)

Read More

Improved Measurements of Sun to Advance Understanding of Climate Change

WASHINGTON — Scientists have taken a major step toward accurately determining the amount of energy that the sun provides to Earth, and how variations in that energy may contribute to climate change.

In a new study of laboratory and satellite data, researchers report a lower value of that energy, known as total solar irradiance, than previously measured and demonstrate that the satellite instrument that made the measurement—which has a new optical design and was calibrated in a new way—has significantly improved the accuracy and consistency of such measurements. (more…)

Read More