Tag: astronomy

Astronomers have found a super-earth exoplanet inside its star’s habitable zone.

6:44 pm

Worlds without end: Astronomers have found a super-earth exoplanet inside its star’s habitable zone.

The planet is large enough that it might be more like Neptune, but if it should have any earth-sized moons they will definitely be capable of supporting life.

Update: The science paper included a wonderful graphic comparing the solar system of this star with that of our own solar system. I have posted this graphic below the fold. HD40307g is the potentially habitable planet.
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A house-sized asteroid will zip past the Earth in February at a distance less than 14,000 miles.

12:43 pm

Chicken Little report: A house-sized asteroid will zip past the Earth in February at a distance less than 14,000 miles.

The asteroid, referred to as 2012 DA14, has a diameter of approximately 45m and an estimated mass of 130,000 tonnes. It was discovered at the start of 2012 and is set to travel between the Earth and our geostationary communication satellites on 15 February 2013. At a distance of just 22,500km this will be the closest asteroid ‘fly by’ in recorded history. Asteroid and comet researchers will be gathering at the University of Central Florida (UCF) in Orlando, U.S., to watch the event, but experts say there is no chance of a collision – this time.

The claim that this is the closest “fly by” in recorded history sounds bogus to me, but because of the size of this asteroid the fly-by will nonetheless be quite interesting. Scientists should be able to get a very good look at 2012 DA14 as it goes by.

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The supermassive black hole in the center of the Milky Way is about to get a snack.

6:16 pm

The supermassive black hole in the center of the Milky Way is about to get a snack.

Update: The recently launched NuStar telescope in July detected its first flare from the central black hole (which by the way is called Sagittarius A* and is pronounced Sagittarius A-star). If the gas cloud produces any fireworks as it whips past the black hole in the coming year then NuStar should see it.

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Kepler reveals our Sun might be more variable than we imagine

5:13 pm

More exoplanet news: The problems of Kepler.

The article outlines the status — both good and bad — of Kepler in its hunt for Earthlike exoplanets.

I have already reported on Kepler’s failed reaction wheel. It no longer has a backup and needs every reaction wheel it has to keep it pointed in so precise a manner. Thus, the loss of one more wheel will shut the telescope down.

However, I had not been aware that the scientists now need more than twice as much time, eight years instead of three, to do their work, because they have discovered that sunlike stars are far more variable than expected. To quote the article,
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Astronomers have discovered that the nearest star to the Earth, Alpha Centauri, has an exoplanet only slightly heavier than the Earth.

3:28 pm

Big news: Astronomers have discovered that the nearest star to the Earth, Alpha Centauri, has an exoplanet only slightly heavier than the Earth.

Alpha Centauri is actually a triple star system, with two sunlike stars in a tight orbit around each other and a third star far out orbiting them both. The exoplanet orbits one of the inner stars every 3.2 days.

More details from Nature here.

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A super Earth, made of diamonds

8:55 am

A super Earth, made of diamonds.

Astronomers also thought 55 Cancri e contained a substantial amount of super-heated water, based on the assumption that its chemical makeup was similar to Earth’s, Madhusudhan said. But the new research suggests the planet has no water at all, and appears to be composed primarily of carbon (as graphite and diamond), iron, silicon carbide, and, possibly, some silicates. The study estimates that at least a third of the planet’s mass — the equivalent of about three Earth masses — could be diamond. “By contrast, Earth’s interior is rich in oxygen, but extremely poor in carbon — less than a part in thousand by mass,” says co-author and Yale geophysicist Kanani Lee.

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A star has gone supernova and astronomers get to see it from the very beginning, and even earlier!

7:05 pm

A star has gone supernova and astronomers get to see it from the very beginning, and even earlier!

The star had erupted several times before but had not produced a real supernova explosion. On September 26 it finally did so. Moreover, astronomers have images of the star prior to any eruption, information that until recently was not available for any supernovae.

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Astronomers have discovered a star that circles the supermassive black hole at the center of the Milky Way in only 11.5 years.

5:57 pm

Dizzy: Astronomers have discovered a star that circles the supermassive black hole at the center of the Milky Way in only 11.5 years.

This newly discovered star joins another that is 15 times brighter and has a 16 year orbit. The combined orbital data from both will allow astronomers to measure precisely the size of the black hole while also measuring the distortion of space caused by its intense gravitational field.

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Using data from the Spitzer Space Telescope astronomers have narrowed the universe’s rate of expansion to about 74.3 kilometers per second per megaparsec.

11:22 am

The uncertainty of science: Using data from the Spitzer Space Telescope astronomers have narrowed the universe’s rate of expansion to about 74.3 kilometers per second per megaparsec.

The importance of this number, also called the Hubble Constant, is that it allows astronomers to extrapolate more precisely backward to when they believe the Big Bang occurred, about 13.7 billion years ago. It also is a crucial data point in their effort to understand dark energy, in which this expansion rate is actually accelerating on vast scales.

Back in 1995 a team led by Wendy Freedman, the same scientist leading the work above, announced that they had used the Hubble Space Telescope to determine the expansion rate as 80 kilometers per second per megaparsec. Then, the margin of error was plus or minus 17 kilometers. Now the margin of error has been narrowed to plus or minus 2.1 kilometers.

Do I believe these new numbers? No, not really. Science has nothing to do with belief. I do think this is good science, however, and that this new estimate of the Hubble constant is probably the best yet. I would also not be surprised if in the future new data eventually proves this estimate wrong.

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The solar maximum has already occurred in the Sun’s northern hemisphere, according to new observations.

9:16 am

The solar maximum has already occurred in the Sun’s northern hemisphere, according to one scientist’s research.

Moreover, the data also suggests that the maximum in the Sun’s southern hemisphere will not occur until early in 2014. This asymmetry between the hemispheres also suggests the strong possibility of a Grand Minimum to follow.

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