Tag: astronomy

In a paper published today in Science, astronomers show that Type 1a supernovae, the kind used to measure the expansion rate of the universe, can be caused in more than one way, something not previously expected.

11:44 am

The uncertainty of science: In a paper published today in Science, astronomers show that Type 1a supernovae, the kind used to measure the expansion rate of the universe, can be caused in more than one way, something not previously expected.

Andy Howell, second author on the study, said: “It is a total surprise to find that thermonuclear supernovae, which all seem so similar, come from different kinds of stars. It is like discovering that some humans evolved from ape-like ancestors, and others came from giraffes. How could they look so similar if they had such different origins?” Howell is the leader of the supernova group at LCOGT, and is an adjunct faculty member in physics at UCSB.

Recently, some studies have found that Type Ia supernovae are not perfect standard candles –– their brightness depends on the type of galaxy in which they were discovered. The reason is a mystery, but the finding that some Type Ia supernovae come from different progenitors would seem to suggest that the supernova’s ultimate brightness may be affected by whether or not it comes from a nova or a white dwarf merger.

“We don’t think this calls the presence of dark energy into question,” said Dilday. “But it does show that if we want to make progress understanding it, we need to understand supernovae better.”

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Astronomers have found what they believe is the first evidence of a planet consumed by its star as the star expanded and aged.

5:33 pm

Astronomers have found what they believe is the first evidence of a planet consumed by its star as the star expanded and aged.

Sadly, for those of you out there who like the idea of watching planets getting destroyed, the event happened a long time ago, and all the astronomers have is circumstantial evidence that is most likely explained by such an event.

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Astronomers have now confirmed 41 new exoplanets, first pinpointed by the Kepler space telescope

5:20 pm

Astronomers have now confirmed 41 new exoplanets, first pinpointed by the Kepler space telescope.

One paper, by Jiwei Xie at the University of Toronto, confirms 24 new planets in 12 systems. Another study, by Steffen and his colleagues, confirms 27 planets in 13 systems. Five of the systems, and 10 of the planets, are the same in both papers. All in all, the new research adds 20 new planetary systems to the 47 that Kepler had previously confirmed, marking a more than 40 percent increase.

Among the Kepler candidates are five Earth-sized planets in the habitable zone, according to the vidoe at the link. However, this announcement does not tell us if any of those candidates were confirmed by these two papers.

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Facing tight budgets, a National Science Foundation panel has recommended the shuttering of five major ground-based telescopes.

5:46 pm

Facing tight budgets, a National Science Foundation panel has recommended the shuttering of five major ground-based telescopes.

Stay tuned for loud screams of outrage. However, some of these facilities have not been very useful for years. Consider the Robert C. Byrd Green Bank Radio Telescope. It was only rebuilt after it collapsed in 1988 because of the political clout of Senator Robert Byrd. By the time that reconstruction was finished, a process that took more than 20 years, the telescope was completely obsolete. Though it has done some good science, it is far outmatched by other radio telescope arrays.

Many of the facilities are funded merely due to bureaucratic and political inertia. For the astronomical community to be willing to recognize this is a good thing, for which they should be lauded.

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More signs that the Voyager 1 spacecraft is about to enter interstellar space.

2:27 pm

More signs that the Voyager 1 spacecraft is about to enter interstellar space.

For the last seven years, Voyager 1 has been exploring the outer layer of the bubble of charged particles the sun blows around itself. In one day, on July 28, data from Voyager 1’s cosmic ray instrument showed the level of high-energy cosmic rays originating from outside our solar system jumped by five percent. During the last half of that same day, the level of lower-energy particles originating from inside our solar system dropped by half. However, in three days, the levels had recovered to near their previous levels.

A third key sign is the direction of the magnetic field, and scientists are eagerly analyzing the data to see whether that has, indeed, changed direction. Scientists expect that all three of these signs will have changed when Voyager 1 has crossed into interstellar space. A preliminary analysis of the latest magnetic field data is expected to be available in the next month.

Based on this report, expect scientists to announce that Voyager 1 has left the solar system sometime before the end of the year.

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Have astronomers found a future supernova?

1:49 pm

A press release from the Carnegie Institute today described a recent paper by astronomers that might have identified a star in the Milky Way that might go supernova sometime in the future. The star QU Carinae, is a cataclysmic variable, a binary system in which material dumped from one star onto another periodically causes an outburst of X-rays.

I emailed Stella Kafka, the lead scientist of the research paper, to find out how far away QU Carinae is and how soon it might go supernova. She responded as follows:
» Read more

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One of Kepler’s reaction wheels — used to orient the space telescope — has failed.

7:08 pm

Bad news: One of Kepler’s four reaction wheels — used to orient the space telescope — has failed.

Kepler only needs three wheels to function – one to control the probe’s motion along each axis – and the probe resumed its observations on 20 July. “Kepler is functioning very well on three reaction wheels,” says mission manager Roger Hunter of NASA’s Ames Research Center in Moffett Field, California. If the glitch can’t be fixed, though, Kepler will be left without a backup wheel. “This is reducing the odds of making the mission go as long as we can,” says Kepler chief scientist William Borucki of NASA Ames, who doubts that Kepler could point accurately enough to look for transiting planets if reduced to two reaction wheels. “It was a disappointing surprise to find this wheel stopped so early.”

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Some spectacular images of galaxies from the new Discovery Channel Telescope.

9:26 am

Some spectacular images of galaxies from the new Discovery Channel Telescope (DCT).

Funded privately by the Discovery channel, the DCT has a primary mirror 4.3 meters wide, or about 170 inches, almost as large as the Hale Telescope on Palomar Mountain. This is a world class telescope which will do real research, and it was built the old-fashioned way, with private money donated to a private observatory in exchange for publicity and good will.

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Astronomers have discovered the first exoplanet smaller than Earth.

9:19 am

Astronomers have discovered the first exoplanet smaller than Earth.

The University of Central Florida has detected what could be its first planet, only two-thirds the size of Earth and located right around the corner, cosmically speaking, at a mere 33-light years away. The exoplanet candidate called UCF 1.01, is close to its star, so close it goes around the star in 1.4 days. The planet’s surface likely reaches temperatures of more than 1,000 degrees Fahrenheit. The discoverers believe that it has no atmosphere, is only two-thirds the gravity of Earth and that its surface may be volcanic or molten.

What is especially remarkable about this discovery is that the scientists used the Spitzer Space Telescope to do it, detecting the planet’s transits across the star’s face, just like Kepler. Spitzer was not designed to be able to do this.

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Astronomers have found four different binary star systems with the stars orbiting so close to each other that they complete their orbits in less than four hours, orbits that astronomers had previously believed “impossible.”

9:09 am

The uncertainty of science: Astronomers have found four different binary star systems with the stars orbiting so close to each other that they complete their orbits in less than four hours, orbits that astronomers had previously believed “impossible.”

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Scientists have found a previously unknown mineral embedded in a meteorite that crashed to Earth in 1969.

4:55 pm

Scientists have found a previously unknown mineral embedded in a meteorite that crashed to Earth in 1969.

Dubbed panguite, the new titanium oxide is named after Pan Gu, the giant from ancient Chinese mythology who established the world by separating yin from yang to create the earth and the sky. … “Panguite is an especially exciting discovery since it is not only a new mineral, but also a material previously unknown to science,” says Chi Ma, a senior scientist and director of the Geological and Planetary Sciences division’s Analytical Facility at Caltech and corresponding author on the paper.

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Two exoplanets in a tight orbital dance.

12:31 pm

Two exoplanets in a tight orbital dance.

“These are the closest two planets to one another that have ever been found,” Agol said. “The bigger planet is pushing the smaller planet around more, so the smaller planet was harder to find.”

Orbiting a star in the Cygnus constellation referred to as Kepler-36a, the planets are designated Kepler-36b and Kepler-36c. Planet b is a rocky planet like Earth, though 4.5 times more massive and with a radius 1.5 times greater. Kepler-36c, which could be either gaseous like Jupiter or watery, is 8.1 times more massive than Earth and has a radius 3.7 times greater.

But wait, there’s more!

The fact that the two planets are so close to each other and exhibit specific orbital patterns allowed the scientists to make fairly precise estimates of each planet’s characteristics, based on their gravitational effects on each other and the resulting variations in the orbits. To date, this is the best-characterized system with small planets, the researchers said.

They believe the smaller planet is 30 percent iron, less than 1 percent atmospheric hydrogen and helium and probably no more than 15 percent water. The larger planet, on the other hand, likely has a rocky core surrounded by a substantial amount of atmospheric hydrogen and helium.

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