Tag: astronomy

Cosmologists, using new data, are now reconsidering their theories on the manner in which the universe began organizing itself after the Big Bang.

9:08 am

The uncertainty of science: Cosmologists, using new data, are now reconsidering their theories on the manner in which the universe began organizing itself after the Big Bang.

Scientists call it the epoch of reionization, the period in which a newborn universe went from darkness to light as the first stars, galaxies and black holes began forming and radiating energy.

In a paper published Thursday in Nature, researchers are challenging one long-held conception about how quickly the universe began warming during this transition period. Based on observations of X-ray emissions from binary star systems, as well as new mathematical models, cosmologists at Tel Aviv University and Harvard say that heating of the universe progressed much more slowly, and uniformly, than previously thought.

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Jupiter’s shrinking Great Red Spot.

9:34 am

Jupiter’s shrinking Great Red Spot.

In the 1880s the GRS resembled a huge blimp gliding high above white crystalline clouds of ammonia and spanned 40,000 km (25, 000 miles) across. You couldn’t miss it even in those small brass refractors that were the standard amateur observing gear back in the day. Nearly one hundred years later in 1979, the Spot’s north-south extent has remained virtually unchanged, but it’s girth had shrunk to 25,000 km (15,535 miles) or just shy of two Earth diameters. Recent work done by expert astrophotographer Damian Peach using the WINJUPOS program to precisely measure the GRS in high resolution photos over the past 10 years indicates a continued steady shrinkage.

Lots more fascinating information at the link. Read it all.

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The National Science Foundation wants to get rid of some of its older big telescopes, and you can buy them!

9:05 am

The National Science Foundation wants to get rid of some of its older big telescopes, and you can buy them!

We are not talking small here. The biggest is the Green Bank Radio Telescope in West Virginia, which though only fourteen years old is unable to compete scientificially with the new large radio telescope arrays. In truth, when it was mostly built to satisfy the pork ambitions of the late Democratic Senator Robert Byrd.

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For more information about that newly discovered supernova in the nearby galaxy M82 go here and here.

9:50 am

For more information about that newly discovered supernova in the nearby galaxy M82 go here and here.

The first link notes that the supernova has brightened to 11.5 magnitude and could get even brighter in the next two weeks. Though still too dim for the naked eye, it is easily bright enough right now for most amateur telescopes and binoculars. How much brighter it will get remains a question.

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Astronomers have detected water vapor spurting from Ceres, the solar system’s largest asteroid.

9:41 am

Using the Herschel Space Telescope astronomers have detected water vapor spurting from Ceres, the solar system’s largest asteroid.

Herschel’s sensors spied plumes during three of the four observation periods. The strength of absorption varied over a matter of hours, a trend probably caused by relatively small sources of water vapour rotating in and out of view of Earth, the researchers say.

Data gathered in March 2013 suggest that the plumes originated from two widely separated, 60-kilometre-wide spots in the dwarf planet’s mid-latitude regions. Together, these spots ejected about 6 kilograms of water vapour into space each second. Neither ground-based observations nor images from the Hubble Space Telescope are keen enough to identify the as-yet-mysterious areas, says Küppers. “We don’t know what these features are, we just know that they’re darker than their surroundings,” he notes.

The NASA probe Dawn will arrive at Ceres early next year, and take a good look at these plumes. Should be exciting.

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Astronomers have discovered the first exoplanets orbiting a star almost identical to the Sun.

2:13 pm

Astronomers have discovered the first exoplanet orbiting a star almost identical to the Sun.

Astronomers have used ESO’s HARPS planet hunter in Chile, along with other telescopes around the world, to discover three planets orbiting stars in the cluster Messier 67. Although more than one thousand planets outside the Solar System are now confirmed, only a handful have been found in star clusters. Remarkably one of these new exoplanets is orbiting a star that is a rare solar twin — a star that is almost identical to the Sun in all respects.

This discovery is interesting in that some astronomers have proposed that our Sun itself was born in M67, the open galactic star cluster where these exoplanets were found. My March 2012 cover story for Sky & Telescope was on this very subject.

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Astronomers have identified a star they expect to go supernova very soon.

8:56 am

Astronomers have identified a star they expect to go supernova very soon.

[SBW2007] 1 (or SBW1) is located 20,000 light-years from Earth and features an enigmatic double-ringed planetary nebula. The rings are gases that have been blasted from the outermost layers of the blue supergiant star in the nebula’s core. The star, which was estimated to be 20 times the mass of the sun before it became unstable, is going through its final death throes before a supernova is initiated. But don’t worry, the supernova would be a safe distance from us, although it will put on an exciting light show.

There is no way to predict when the supernova will occur. On the timescales of stellar evolution, it could happen tomorrow, or in a thousand years. For the full Hubble image go here.

This story is significant in that it shows how much knowledge has been gained in astronomy since Hubble’s launch. In 1987, when Supernova 1987a exploded in the Large Magellanic Cloud, astronomers had not identified even one progenitor of any supernova, and did not have any clear idea what kinds of stars produced these gigantic explosions. Today, they have identified more than a handful, and are even beginning to pinpoint candidates, such as the star above, that could be the next stars to go boom.

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Astronomers announced today the discovery of several dozen stars which are traveling so fast they will escape the Milky Way galaxy.

5:59 pm

Astronomers announced today the discovery of 18 sunlike stars which are traveling so fast they will escape the Milky Way galaxy.

These sunlike stars are in addition to another 20 blue giant stars that are also traveling at escape velocity.

The origin of all of these new stars is completely mysterious. The theory had been that such stars got their speed boost by being flung past the galaxy’s central supermassive black hole, dubbed Sagittarius A* (pronounced “A-star”). These new stars, however, come from other directions, and in fact appear to have even come from outside the galaxy’s main disk. Thus, astronomers are baffled as to what caused them to be traveling so fast.

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The recently reactivated WISE space telescope has discovered its first new asteroid.

3:31 pm

The recently reactivated WISE space telescope has discovered its first new asteroid.

2013 YP139 is about 27 million miles (43 million kilometers) from Earth. Based on its infrared brightness, scientists estimate it to be roughly 0.4 miles (650 meters) in diameter and extremely dark, like a piece of coal. The asteroid circles the sun in an elliptical orbit tilted to the plane of our solar system and is classified as potentially hazardous. It is possible for its orbit to bring it as close as 300,000 miles from Earth, a little more than the distance to the moon. However, it will not come that close within the next century.

WISE, renamed NEOWISE by NASA, is expected to come up with a lot more of these in the coming years.

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Astronomers, using Kepler data, have identified dozens of exoplanets between 1 and 4 times the mass of the Earth.

3:23 pm

Worlds without end: Astronomers, using Kepler data, have identified dozens of exoplanets between 1 and 4 times the mass of the Earth.

One of those planets has the same mass as the Earth, but is far less dense.

The significant fact however that came out of the press conference announcing these results is the belief by astronomers that, based on this data, they expect that 1 in 5 solar systems will have an Earth-sized planet.

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Scientists think they have found cloudy skies on a nearby super Earth.

9:25 am

Scientists think they have found cloudy skies on two nearby exoplanets.

One planet is a super Earth, while the other is Neptune-sized.

This finding, as fascinating as it is, is also incredibly uncertain. The data suggests clouds, but the data is quite thin. We are barely seeing what’s there. Without doubt, the reality is far more complex — and interesting — than presently theorized.

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WISE, the Wide Field Infrared Survey Explorer, sent back its first images in almost three years this week.

5:57 pm

Back from the dead: WISE sent back its first images in almost three years this week.

The Near-Earth Object Wide-field Infrared Survey Explorer spacecraft, or NEOWISE, has taken its first set of test images since being reactivated in September after a 31-month-long hibernation, NASA officials announced today (Dec. 19). The space agency wants NEOWISE to resume its hunt for potentially dangerous asteroids, some of which could be promising targets for future human exploration.

We should note that NASA had shut down this functional space telescope even though the cost to use it to hunt asteroids would be relatively little. Cost was cited as the reason, but I suspect it was a combination of the vast overruns for the James Webb Space Telescope and the Obama administration’s puzzling hostility to science at NASA.

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Gaia, a astronomical space probe designed to pinpoint the location of a billion stars to map the Milky Way, was successfully launched today.

9:08 am

Gaia, a astronomical space probe designed to pinpoint the location of a billion stars to map the Milky Way, was successfully launched today.

This is an important spacecraft, but don’t expect to hear anything about its work now for a long time, as it will take a few years to accumulate the data involved and then a years beyond that to analyze it. Nonetheless, when Gaia’s work is finished we will have our first reasonably good map of the Milky Way, with the ability to project that map forward and backward in time.

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