Tag Archives: sun

From Cassini for the Holidays: A Splendor Seldom Seen

By Guest PostDecember 20, 2012Sciencecarolyn porco, cassini spacecraft, dark side, earth, european space agency, high solar phase, in saturns shadow, jpl, NASA, orbit, planet saturn, rings, saturn, sun

PASADENA, Calif — Just in time for the holidays, NASA’s Cassini spacecraft, in orbit around Saturn for more than eight years now, has delivered another glorious, backlit view of the planet Saturn and its rings.

On Oct. 17, 2012, during its 174th orbit around the gas giant, Cassini was deliberately positioned within Saturn’s shadow, a perfect location from which to look in the direction of the sun and take a backlit view of the rings and the dark side of the planet. Looking back towards the sun is a geometry referred to by planetary scientists as “high solar phase;” near the center of your target’s shadow is the highest phase possible. This is a very scientifically advantageous and coveted viewing position, as it can reveal details about both the rings and atmosphere that cannot be seen in lower solar phase. (more…)

Can Life Emerge on Planets Around Cooling Stars?

By Guest PostNovember 20, 2012Scienceastronomers, astrophysics, brown dwarf, earth, Germany, habitable zone, heating phenomenon, ingredients, leibniz institute, life, liquid, nuclear burning, phase, planets, potsdam, rene heller, rory barnes, runaway greenhouse, sun, support, university, venus, Washington

Astronomers find planets in strange places and wonder if they might support life. One such place would be in orbit around a white or brown dwarf. While neither is a star like the sun, both glow and so could be orbited by planets with the right ingredients for life.

No terrestrial, or Earth-like planets have yet been confirmed orbiting white or brown dwarfs, but there is no reason to assume they don’t exist. However, new research by Rory Barnes of the University of Washington and René Heller of Germany’s Leibniz Institute for Astrophysics Potsdam hints that planets orbiting white or brown dwarfs will prove poor candidates for life. (more…)

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

By Guest PostSeptember 3, 2012Scienceaustin, bill cochran, binary star, caroline caldwell, faint star, giant magellan telescope, habitable zone, harlan j smith, het, hobby eberly telescope, jerome orosz, kepler 47, kepler mission, largest telescope, m dwarf star, mcdonald observatory, michael endl, multi planet, NASA, one system, planet, primary star, san diego, secondary star, solar system, space telescope, state university, stellar eclipse, sun, tatooine, telescope, texas, transit, university, west texas, william welsh, world

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…)

Astronomers Test Einstein in a New Regime Using Pair of Burnt-Out Stars

By Guest PostAugust 31, 2012Sciencealbert einstein, apache point telescope, astronomer, austin, burnt out stars, canary islands, carlos allende prieto, don winget, dwarf stars, einstein, emission, energy, european space agency, fabric, Galaxy, gemini north telescope, general relativity, gran telescopio canarias, gravitational wave, hawaii, j j hermes, j0651, mcdonald observatory, milliseconds, moving object, mukremin kilic, NASA, new mexico, new regime, orbital decay, orbital period, otto struve telescope, ripple, space time, spain, sun, test, texas, theory, university, university of oklahoma, warren brown, west texas

AUSTIN, Texas — A team of astronomers led by researchers from The University of Texas at Austin has confirmed the emission of gravitational waves from the second-strongest known source in our galaxy by studying the shrinking orbital period of a unique pair of burnt-out stars. Their observations tested Albert Einstein’s theory of general relativity in a new regime. The results will be published soon in The Astrophysical Journal Letters.

Last year, the same team discovered that the two white dwarf stars are so close together that they make a complete orbit in less than 13 minutes, and they should be gradually slipping closer. The system, called SDSS J065133.338+284423.37 (J0651 for short), contains two white dwarf stars, which are the remnant cores of stars like our sun. (more…)

Solar Storm Protection

By Guest PostJuly 17, 2012Scienceastronaut, chest xray, chungnam national university, hanyang university, john bieber, john clem, massive explosion, megaelectron volts, mev, neutron monitors, paul evenson, polar region, protection, r pyle, sdo, solar dynamics observatory, solar storm, south korea, south pole, Space, su yeon oh, sun, university of delaware, warning system, yu yi

Warning system to protect astronauts from solar storms

Massive explosions on the sun unleash radiation that could kill astronauts in space.

Now, researchers from the U.S. and South Korea have developed a warning system capable of forecasting the radiation from these violent solar storms nearly three hours (166 minutes) in advance, giving astronauts, as well as air crews flying over Earth’s polar regions, time to take protective action.

Physicists from the University of Delaware and from Chungnam National University and Hanyang University developed the system and report on it in Space Weather: The International Journal of Research and Applications, published by the American Geophysical Union. The research article also is selected as an “Editor’s Highlight.” (more…)

Scientists Discover New Trigger for Immense North Atlantic Ocean Spring Plankton Bloom

By Guest PostJuly 7, 2012Environmentadam huxtable, amala mahadevan, atlantic ocean, biological pump, bjarni saemundsson, carbon dioxide, climate, climate on earth, CO2, craig lee, diatoms, don rice, eddies, emily kallin, eric d asaro, fossil fuel, global carbon cycle, holiday fireworks, mary jane perry, michael ohmart, microscopic plants, modulate, north atlantic bloom, not sunlight, nsf, ocean physics, oceanic cycling, oxygen, photosynthesis, physical biological model, phytoplankton, research vessel, silica, sun, surface warming, university of maine, university of washington, us beachgoers, whirlpools, whoi, zooplankton

Ocean eddies help jump-start plankton blooms that spread across hundreds of square miles

On this July 4^th week, U.S. beachgoers are thronging their way to seaside resorts and parks to celebrate with holiday fireworks. But across the horizon and miles out to sea toward the north, the Atlantic Ocean’s own spring and summer ritual unfolds. It entails the blooming of countless microscopic plants, or phytoplankton.

In what’s known as the North Atlantic Bloom, an immense number of phytoplankton burst into existence, first “greening,” then “whitening” the sea as one or more species take the place of others.

What turns on this huge bloom, what starts these ocean fireworks? Is it the Sun’s warmth? (more…)

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

By Guest PostJune 8, 2012Scienceadam block, alan strauss, astrophotographer, black void, digital slr camera, earth, east coast, England, exoplanets, expedition, filaments, Hubble Space Telescope, hydrogen alpha filter, jeremiah horrocks, liverpool, martin hamar, mount lemmon skycenter, much hoole, planet, planet venus, schulman telescope, southern arizona, sun, telescope, transit of venus, ua, venus, venus transit, village

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…)

Fossil Raindrop Impressions Imply Greenhouse Gases Loaded Early Atmosphere

By Guest PostApril 2, 2012Environmentames research center, atmosphere, atmospheric pressure, concentration, david catling, earth history, fossilized, greenhouse gases, jelte harnmeijer, latex peels, liquid water, low carbon innovation, peter polivka, pressure broadening, raindrop impression, raindrop velocity, roger buick, sanjoy som, seattle, South Africa, sun, temperature, warm temperature

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…)