Tag: astronomy

Despite a rest, Kepler’s problematic gyroscope is still having problems.

9:26 am

Despite a rest, Kepler’s problematic gyroscope is still having problems.

Three of the wheels are needed for Kepler’s 3.1-foot telescope to have enough sensitivity to detect the minuscule signatures of Earth-sized planets. In an exercise of caution, mission managers switched off Kepler’s reaction wheels for 10 days in January, hoping the break would redistribute lubricant inside the wheel assemblies, reducing friction and allowing the units to cool down.

But friction in wheel no. 4, which has showed friction for much of Kepler’s mission, actually increased in the month following the “wheel rest” period.

The telescope originally had four wheels. One has failed, with a second showing signs of failure. If it goes, the spacecraft will no longer be able to point with enough accuracy to do its primary mission. They might be able to use it to some observations, but its design is such that even these will be of limited value.

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The location of the volcanoes on Titan are not where scientists had expected them to be.

9:30 am

The uncertainty of science: The location of the volcanoes on Titan are not where scientists had expected them to be.

As Io moves closer to Jupiter, the planet’s powerful gravity pulls hard on the moon, deforming it. This force decreases as Io retreats, and the moon bounces back. This cycle of flexing creates friction in Io’s interior, which in turn generates enormous amounts of volcano-driving tidal heat. Common sense suggests that Io’s volcanoes would be located above the spots with the most dramatic internal heating. But Hamilton and his colleagues found that the volcanoes are significantly farther to the east than expected.

Many of the news headlines, including the article above, have trumpeted how the volcanoes on Io are in the wrong place. (See also this article.) Not. The theories were wrong, not the volcanoes. Nature does what it wants to do. It is our job to figure out why.

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Using Hubble astronomers have confirmed that it was a yellow supergiant star that was the progenitor for the nearest supernovae in decades that occurred in 2011.

9:12 am

Using Hubble astronomers have confirmed that it was a yellow supergiant star that was the progenitor for the nearest supernovae in decades, that occurred in 2011 in the Whirlpool Galaxy.

The uncertainty of science: As I noted in 2011 when the yellow supergiant was first detected in pre-explosion images. no theory at that time had ever proposed this kind of star as a supernova progenitor. The discovery has thus required the theorists to come up with new theories.

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The Alpha Magnetic Spectrometer on ISS has detected a surplus of positrons, anti-matter electrons, that physicists believe are caused by the existence of dark matter.

9:28 am

The Alpha Magnetic Spectrometer on ISS has detected a surplus of positrons, anti-matter electrons, that physicists believe are caused by the existence of dark matter.

The lead scientist of the experiment also emphasized that dark matter is not the only possible explanation, and that “The detailed interpretation of our data probably will have many theories.”

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Astronomers watch the central supermassive black hole of a galaxy eat something, either a planet or a brown dwarf.

9:24 am

Astronomers watch the central supermassive black hole of a galaxy eat something, either a planet or a brown dwarf.

Astronomers were using Integral to study a different galaxy when they noticed a bright X-ray flare coming from another location in the same wide field-of-view. Using XMM-Newton, the origin was confirmed as NGC 4845, a galaxy never before detected at high energies. Along with Swift and MAXI, the emission was traced from its maximum in January 2011, when the galaxy brightened by a factor of a thousand, and then as it subsided over the course of the year. “The observation was completely unexpected, from a galaxy that has been quiet for at least 20–30 years,” says Marek Nikolajuk of the University of Bialystok, Poland, lead author of the paper in Astronomy & Astrophysics.

By analysing the characteristics of the flare, the astronomers could determine that the emission came from a halo of material around the galaxy’s central black hole as it tore apart and fed on an object of 14–30 Jupiter masses. This size range corresponds to brown dwarfs, substellar objects that are not massive enough to fuse hydrogen in their core and ignite as stars. However, the authors note that it could have had an even lower mass, just a few times that of Jupiter, placing it in the range of gas-giant planets.

All the instruments listed above are orbiting space telescopes. You can read the science paper here.

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Having lost its earmarked government funding in 2011, the Pan-STARRS telescope has now replaced those funds with a private donation.

10:14 am

We don’t need no stinking government: Having lost its earmarked government funding in 2011, the Pan-STARRS telescope has now replaced those funds with a private donation.

I find it interesting that while the lost government funds equaled $10 million, they are now able to achieve essentially the same goals with a private donation of only $3 million. This suggests, not surprisingly, that there was a lot of extra pork in the government funds that the facility could manage without.

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