Tag Archives: hubble

Mirror, mirror in the sky….

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Bad stepmom would have loved it. The Moon as a mirror.

Scientists are planning to use NASA’s Hubble Space Telescope to observe next month’s historic transit of Venus across the sun’s face.

But there’s a twist. Researchers can’t point Hubble anywhere near the sun, because our star’s bright light could damage the telescope’s super-sensitive instruments. So Hubble will watch the June 5-6 Venus transit by using the moon as a mirror.

The goal is to see if Hubble can determine the makeup of Venus’ atmosphere by studying sunlight that has poured through it. Astronomers already know a great deal about Venus’ air, so next month’s observations are a test run to see if the technique could be used to determine the atmospheric composition of faraway alien planets, researchers said… (SPACE.com)

Becoming spaghetti

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A star wanders too close to a black hole. And before you know it, you are one long piece of spaghetti. Enjoy your meal.

Astronomers have gathered the most direct evidence yet of a supermassive black hole shredding a star that wandered too close.

Supermassive black holes, weighing millions to billions times more than the Sun, lurk in the centers of most galaxies. These hefty monsters lay quietly until an unsuspecting victim, such as a star, wanders close enough to get ripped apart by their powerful gravitational clutches.

Astronomers have spotted these stellar homicides before, but this is the first time they can identify the victim. Using a slew of ground- and space-based telescopes, a team of astronomers led by Suvi Gezari of The Johns Hopkins University in Baltimore, Md., has identified the victim as a star rich in helium gas. The star resides in a galaxy 2.7 billion light-years away. .. (Hubble)

A dangerous nebula

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No, they’re not dangerous, they’re beautiful creatures. Spiders are cool and great and small at the same time. So is their celestial sister:

To celebrate its 22nd anniversary in orbit, the Hubble Space Telescope has released a dramatic new image of the star-forming region 30 Doradus, also known as the Tarantula Nebula because its glowing filaments resemble spider legs. A new image from all three of NASA’s Great Observatories – Chandra, Hubble, and Spitzer – has also been created to mark the event. … (HUBBLE)

Jewels of the sky

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A jewel box, one of the many in our skies:

The Hubble Space Telescope has produced the most detailed image so far of Messier 9, a globular star cluster located close to the center of the galaxy. This ball of stars is too faint to see with the naked eye, yet Hubble can see over 250,000 individual stars shining in it.
Messier 9, pictured here, is a globular cluster, a roughly spherical swarm of stars that lies around 25,000 light-years from Earth, near the center of the Milky Way, so close that the gravitational forces from the galactic center pull it slightly out of shape. … (NASA)

A drama in 3D

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At the turn of the 19th century, the binary star system Eta Carinae was faint and undistinguished. In the first decades of the century, it became brighter and brighter, until, by April 1843, it was the second brightest star in the sky, outshone only by Sirius (which is almost a thousand times closer to Earth). In the years that followed, it gradually dimmed again and by the 20th century was totally invisible to the naked eye.

The star has continued to vary in brightness ever since, and while it is once again visible to the naked eye on a dark night, it has never again come close to its peak of 1843.

The larger of the two stars in the Eta Carinae system is a huge and unstable star that is nearing the end of its life, and the event that the 19th century astronomers observed was a stellar near-death experience. Scientists call these outbursts supernova impostor events, because they appear similar to supernovae but stop just short of destroying their star. … (Hubble)

Steamy windows for possible settlers

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This looks like a mighty cool – hot – planet. A waterworld under an atmosphere of water vapor. There could be boiling some life over there! It’s clear (yet damp) that there’s a whole lot more to (exo)planets than the casual rock- and gas planets we have in our neighborhood:

Observations by the NASA/ESA Hubble Space Telescope have come up with a new class of planet, a waterworld enshrouded by a thick, steamy atmosphere. It’s smaller than Uranus but larger than Earth.

An international team of astronomers led by Zachory Berta of the Harvard-Smithsonian Center for Astrophysics (CfA) made the observations of the planet GJ 1214b.

“GJ 1214b is like no planet we know of,” Berta said. “A huge fraction of its mass is made up of water.”

The ground-based MEarth Project, led by CfA’s David Charbonneau, discovered GJ 1214b in 2009. This super-Earth is about 2.7 times Earth’s diameter and weighs almost seven times as much. It orbits a red-dwarf star every 38 hours at a distance of 2 million kilometers, giving it an estimated temperature of 230 degrees Celsius.

In 2010, CfA scientist Jacob Bean and colleagues reported that they had measured the atmosphere of GJ 1214b, finding it likely that it was composed mainly of water. However, their observations could also be explained by the presence of a planet-enshrouding haze in GJ 1214b’s atmosphere. … (Hubble)

Ice fiesta on Vesta?

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Though generally thought to be quite dry, roughly half of the giant asteroid Vesta is expected to be so cold and to receive so little sunlight that water ice could have survived there for billions of years, according to the first published models of Vesta’s average global temperatures and illumination by the sun.

“Near the north and south poles, the conditions appear to be favorable for water ice to exist beneath the surface,” says Timothy Stubbs of NASA’s Goddard Space Flight Center in Greenbelt, Md., and the University of Maryland, Baltimore County. Stubbs and Yongli Wang of the Goddard Planetary Heliophysics Institute at the University of Maryland published the models in the January 2012 issue of the journal Icarus. The models are based on information from telescopes including NASA’s Hubble Space Telescope. …(NASA)