Former astronaut John Grunsfeld is to take over NASA’s science post from Ed Weiler

Excellent choice: Former astronaut John Grunsfeld has been picked to take over NASA’s chief science post from Ed Weiler.

Not only is Grunsfeld an excellent choice, his experience as an astronaut repairing Hubble will help improve relations between the science and manned space programs. In the past, scientists have often argued against manned space, trying to get that money for their unmanned research probes. Instead, when manned space got cut, so did science, and no one won. Grunsfeld’s leadership I think will forestall these short-sighted complaints.

The supernova of a generation

The supernova of a generation.

There will be a slew of stories about this in the next few days. The important takeaways are as follows:

  • After almost a half century, astronomers have finally proven the theory that type Ia supernovae come from the explosion of a white dwarf star, overloaded with material sucked from its binary companion.
  • The prediction that the companion would be a red giant star, however, has turned out to be wrong. At the same time, astronomers still do not know what kind of star it was in this particular case.
  • With this new knowledge astronomers will have a better chance of identifying type Ia supernovae, before they go boom.
  • Finally, type Ia supernovae are used to measure the expansion rate of the universe, and thus were the key to discovering dark energy. By better understanding how these supernovae occur, cosmologists will be better able to constrain what they know about dark energy.

An experiment designed to mimic the dynamo at the Earth’s core is about to be turned on.

Mad scientists at their best! An experiment designed to mimic the dynamo at the Earth’s core is about to be turned on.

Ten years in the making, the US$2-million project is nearly ready for its inaugural run. Early next year, the sphere will begin whirling around while loaded with 13,000 kilograms of molten sodium heated to around 105 °C. Researchers hope that the churning, electrically conducting fluid will generate a self-sustaining electromagnetic field that can be poked, prodded and coaxed for clues about Earth’s dynamo, which is generated by the movement of liquid iron in the outer core. If it works, it will be the first time that an experiment that mirrors the configuration of Earth’s interior has managed to recreate such a phenomenon.

This is a really very cool experiment, as we really do not have a good understanding of how planetary magnetic fields are produced.

Two newly discovered supermassive black holes weigh in as the heaviest known

Two newly discovered supermassive black holes weigh in as the heaviest known.

One of the newly discovered black holes is 9.7 billion solar masses and is located in the elliptical galaxy NGC 3842, which is the brightest galaxy in the Leo cluster of galaxies that sits 320 million light years away in the direction of the constellation Leo. The second is as large or larger and sits in the elliptical galaxy NGC 4889, which is the brightest galaxy in the Coma cluster about 336 million light years from Earth in the direction of the constellation Coma Berenices.

It is believed that these heavy supermassive black holes are the kind that produced quasars in the early universe.

Voyager 1 at the edge

This week the American Geophysical Union (AGU) is having its annual fall meeting in San Francisco. Due to the wonders of technology, they are now making their press conferences available to reporters on line. Thus, I will be posting periodic updates after each conference. This will allow my readers to get a heads up on stories they will be seeing in the mainstream press in the next few hours.

Right now they are wrapping up a press conference from the team of the Voyager 1 spacecraft, in which they have described the spacecraft’s status.
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The first observations of a star, just prior to going supernova

Astronomers have for the first time observed the changes that took place in a binary star system in the years before one star in the system erupted as a supernova.

In the first survey of its kind, the researchers have been scanning 25 nearby galaxies for stars that brighten and dim in unusual ways, in order to catch a few that are about to meet their end. In the three years since the study began, this particular unnamed binary system in the Whirlpool Galaxy was the first among the stars they’ve cataloged to produce a supernova.

The astronomers were trying to find out if there are patterns of brightening or dimming that herald the end of a star’s life. Instead, they saw one star in this binary system dim noticeably before the other one exploded in a supernova during the summer of 2011.

Key quote: “Our underlying goal is to look for any kind of signature behavior that will enable us to identify stars before they explode,”

The supernova in question, 2011dh, was the closest supernova in decades, occurring in June 2011 in the Whirlpool Galaxy (M51). See my previous posts here and here.

‘Perfect black’ coating can render a 3D object flat, raises intriguing dark veil possibility in astronomy

A newly developed “perfect black” coating can render a 3D object flat, which raises an intriguing dark veil possibility in astronomy.

“The carbon nanotube forest can absorb very wide range of electromagnetic wave from ultraviolet up to terahertz,” Guo said, “and in principle it can be applied to an arbitrary sized object.” Just how large an object? Guo suggested an intriguing possibility—perhaps entire planets or even stars. “Since deep space itself is a perfect dark background, if a planet or star were surrounded by a thick, sooty atmosphere of light-absorbing carbon nanomaterial gases, it would become invisible due to the same principle,” Guo said. “It would become totally dark to our instruments that rely on the detection of electromagnetic waves.”

Astronomers have proposed that the cloud of dust that surrounds about 50% of the supermassive black holes at the center of galaxies comes from destroyed planets

Science better than fiction: Astronomers have proposed that the cloud of dust surrounding about 50% of the supermassive black holes at the center of galaxies comes from planets that were ripped apart and smashed by that black hole.

Collisions between these rocky objects would occur at colossal speeds as large as 1000 km per second, continuously shattering and fragmenting the objects, until eventually they end up as microscopic dust. Dr. Nayakshin points out that this harsh environment – radiation and frequent collisions – would make the planets orbiting supermassive black holes sterile, even before they are destroyed. “Too bad for life on these planets”, he says, “but on the other hand the dust created in this way blocks much of the harmful radiation from reaching the rest of the host galaxy. This in turn may make it easier for life to prosper elsewhere in the rest of the central region of the galaxy.”

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