Tag: astronomy

TMT will probably not go to India

10:04 am

An Indian astronomer, in testimony to India’s parliament, has explained that for engineering and technical reasons India will likely not be the new location of the Thirty Meter Telescope (TMT).

Essentially, the skies are clearer in the Canary Islands and in Chile.

This story is important in that it confirms that the consortium building TMT is now very seriously considering abandoning Hawaii, and might already have decided to do so. It also suggests that the Canary Islands is in the lead as the new location, since they want a site that can see the skies of the northern hemisphere, something that won’t be possible in Chile.

6 comments

Physicists fail to find sterile neutrino

9:02 am

The uncertainty of science: A year’s collection of data using IceCube, a gigantic neutrino telescope built in the icecap of Antarctica, has found no evidence of a theorized fourth type of neutrino.

To search for sterile neutrinos, Halzen’s team looked for the arrival of muon neutrinos that started life on the other side of Earth. These were originally produced by the collision of cosmic rays with air molecules in the atmosphere, and passed through the planet to reach the detector. The IceCube team hoped to find a dearth of muon neutrinos at particular energies. That would have suggested that some muon neutrinos had temporarily mutated into sterile neutrinos during their voyage.

But, after analysing the results of a year’s worth of data, the researchers found no feature suggesting the existence of sterile neutrinos around 1 eV. This is line with results from the European Space Agency’s Planck observatory, which concluded from cosmological evidence that there should only be three families of neutrinos in that mass range. “I hope that with our result and with the Planck result we are slowly walking our way back from this story,” says Halzen. The IceCube team are still taking data in their sterile neutrino hunt, but don’t expect their results to change, he adds.

Despite this null result, there is still a possibility that sterile neutrinos exist, but not at the mass predicted.

2 comments

A big Perseid meteor shower on Friday?

8:29 am

According to a new computer model of the Perseid meteor shower, astronomers predict that there could be a big peak of shooting stars on Friday.

Russian astronomer Mikhail Maslov and Finnish astronomer Esko Lyytinen predict that this year the Earth will pass through a stream of cometary material shifted towards us by Jupiter’s gravitational field. According to their model, and work by French scientist Jeremie Vaubaillon, we could see a steep rise in activity from late evening on 11 August to 0500 BST on 12 August.

The Perseids are typically active from around 17 July to 24 August, although for most of that period only a few meteors an hour will be visible. During the peak, and if the predictions by Maslov, Lyytinen and Vaubaillon are right, as many as 100 meteors or more may be seen each hour. This year, the light from the waxing gibbous Moon will interfere to some extent for the first part of the night, so observers are advised to look out in the early morning hours after midnight when the Moon is very low in the sky or has set.

If this is true, Diane and I might have lucked out, as we will be heading for our annual Grand Canyon hike to the bottom on Friday.

0 comments

The mystery of Tabby’s Star deepens

11:15 pm

The uncertainty of science: New data from Kepler has made it even more difficult for scientists to explain the strange fluctuations and dimming of Tabby’s Star.

KIC 8462852, as it is more properly known, flickers so erratically that one astronomer has speculated that nothing other than a massive extraterrestrial construction project could explain its weird behaviour. A further look showed it has been fading for a century. Now, fresh analysis suggests the star has also dimmed more rapidly over the past four years – only adding to the enigma. “It seems that every time someone looks at the star, it gets weirder and weirder,” says Benjamin Montet at the California Institute of Technology, who led the study.

There are as yet no natural explanations for the star’s dimming.

1 comment

Poll shows Hawaiians strongly favor TMT

11:14 pm

A new poll shows that by a 2 to 1 margin Hawaiians are in favor of building the Thirty Meter Telescope (TMT).

  • 89 percent of Hawaii Island residents agree there should be a way for science and Hawaiian culture to co-exist on Maunakea
  • 76 percent of Hawaii Island residents agree that TMT will help create good paying jobs and economic and educational benefits for those living on Hawaii Island
  • 70 percent of Hawaii Island residents agree that failure to move forward with TMT will hurt educational opportunities for Hawaii Island children with the termination of TMT’s annual $1 million contribution to the THINK Fund and workforce pipeline program
  • 69 percent of Hawaii Island residents agree that TMT has followed a lengthy approval process, so work should proceed

Based on what I’ve seen for the past forty years, this poll will mean nothing. The poll also found that the native Hawaiian population was much less supportive, with only 46 percent in support of the project and 45 percent opposed. And since the Democratic Party that runs Hawaii is a party that cares almost exclusively for the concerns of oppressed minorities over that of the non-native majority, you can bet they will do what the native population wants. The telescope will never get built in Hawaii, and the consortium building TMT had better face this reality and find another location.

8 comments

Astrobiologists meet to better their search for exoplanet life

9:25 am

The uncertainty of science: Astrobiologists are meeting this week in Seattle to discuss and refine their methods for detecting astrobiology on exoplanets.

The Seattle meeting aims to compile a working list of biosignature gases and their chemical properties. The information will feed into how astronomers analyse data from NASA’s James Webb Space Telescope, slated for launch in 2018. The telescope will be able to look at only a handful of habitable planets, but it will provide the first detailed glimpse of what gases surround which world, says Nikole Lewis, an astronomer at the Space Telescope Science Institute in Baltimore, Maryland.

No single gas is likely to be a slam-dunk indicator of alien life. But Domagal-Goldman hopes that the workshop will produce a framework for understanding where scientists could trip themselves up. “We don’t want to have a great press release,” he says, “and then a week later have egg on everybody’s faces.”

A few years ago I was told by one astronomer that the field’s biggest and most exciting area of research in the coming decades will be the effort to study the thousands exoplanets they only just discovered. I agree. The Webb telescope might have been built to study cosmology, but the data it will produce about exoplanets will be much more real and less uncertain, thus making it more compelling and convincing.

0 comments

“They can’t be real.”

8:56 am

The uncertainty of science: Astronomers have now detected and measured a new class of large but very dim galaxy that previously was not expected to exist.

‘Ultradiffuse’ galaxies came to attention only last year, after Pieter van Dokkum of Yale University in New Haven, Connecticut, and Roberto Abraham of the University of Toronto in Canada built an array of sensitive telephoto lenses named Dragonfly. The astronomers and their colleagues observed the Coma galaxy cluster 101 megaparsecs (330 million light years) away and detected 47 faint smudges.

“They can’t be real,” van Dokkum recalls thinking when he first saw the galaxies on his laptop computer. But their distribution in space matched that of the cluster’s other galaxies, indicating that they were true members. Since then, hundreds more of these galaxies have turned up in the Coma cluster and elsewhere.

Ultradiffuse galaxies are large like the Milky Way — which is much bigger than most — but they glow as dimly as mere dwarf galaxies. It’s as though a city as big as London emitted as little light as Kalamazoo, Michigan.

More significantly, they have now found that these dim galaxies can be as big and as massive as the biggest bright galaxies, suggesting that, surprise!, there are a lot more stars and mass hidden out there and unseen than anyone had previously predicted.

11 comments

WIMP detector finds nothing

8:36 am

The uncertainty of science: A detector buried a mile underground so that it could only detect the predicted Weak Interacting Massive Particles (WIMP) thought to comprise dark matter has found nothing

Dark matter is thought to account for more than four-fifths of the mass in the universe. Scientists are confident of its existence because the effects of its gravity can be seen in the rotation of galaxies and in the way light bends as it travels through the universe, but experiments have yet to make direct contact with a dark matter particle. The LUX experiment was designed to look for weakly interacting massive particles, or WIMPs, the leading theoretical candidate for a dark matter particle. If the WIMP idea is correct, billions of these particles pass through your hand every second, and also through the Earth and everything on it. But because WIMPs interact so weakly with ordinary matter, this ghostly traverse goes entirely unnoticed.

…“We worked hard and stayed vigilant over more than a year and a half to keep the detector running in optimal conditions and maximize useful data time,” said Simon Fiorucci, a physicist at Berkeley Lab and Science Coordination Manager for the experiment. “The result is unambiguous data we can be proud of and a timely result in this very competitive field—even if it is not the positive detection we were all hoping for.”

This null result, which has its own uncertainties that require confirmation by another experimental test, places significant constraints on the possible nature of the dark matter particle, assuming it exists. And if confirmed, this result makes the hunt to explain the gravitational data of galaxy rotation, something that has been confirmed repeatedly, far more difficult.

3 comments

Nearby exoplanets have Earthlike atmospheres

10:58 am

Worlds without end: New data from Hubble suggests that two rocky exoplanets only 40 light years away have atmospheres more similar to Earth’s than to that of gas giants.

Specifically, they discovered that the exoplanets TRAPPIST-1b and TRAPPIST-1c, approximately 40 light-years away, are unlikely to have puffy, hydrogen-dominated atmospheres usually found on gaseous worlds. “The lack of a smothering hydrogen-helium envelope increases the chances for habitability on these planets,” said team member Nikole Lewis of the Space Telescope Science Institute (STScI) in Baltimore, Maryland. “If they had a significant hydrogen-helium envelope, there is no chance that either one of them could potentially support life because the dense atmosphere would act like a greenhouse.”

The actual make-up of these atmospheres remains unknown. Also, the central star, a red dwarf, is estimated to be about a half billion years old. Both the star’s make-up — red dwarfs are not as rich in elements as a G-type sun — and age do not provide much margin for the development of life.

Nonetheless, the new data increases again the likelihood that we will eventually find habitable worlds orbiting other stars, and we will find them in large numbers.

1 comment

TMT likely to abandon Hawaii

3:55 pm

Officials from the consortium that is building the Thirty Meter Telescope (TMT) have revealed that they are looking very seriously at alternative locations.

Officials behind the proposed Thirty Meter Telescope (TMT) are considering new locations for the $1.4bn facility, and expect to decide whether to opt for a new site early next year. The TMT is due to be built on Hawaii’s Mauna Kea mountain but, following protests from local residents, its building permit was revoked last December by the state’s Supreme Court. New locations that are being considered include Baja California in Mexico, the Canary Islands and Chile, as well as locations in India and China.

They claim that Hawaii is still their first choice, but if they don’t see any progress by summer in the permitting process, I expect them to tell Hawaii to go to hell (though not in those words) and pick somewhere else.

5 comments

A planet with three suns

3:18 pm

Astronomers, using instruments on the Very Large Telescope in Chile, have discovered an exoplanet that orbits around three suns.

Located about 340 light years from Earth in the constellation Centaurus, HD 131399Ab is believed to be about 16 million years old, making it one of the youngest exoplanets discovered to date, and one of very few directly imaged planets. With a temperature of 850 Kelvin (about 1,070 degrees Fahrenheit or 580 degrees Celsius) and weighing in at an estimated four Jupiter masses, it is also one of the coldest and least massive directly imaged exoplanets.

“HD 131399Ab is one of the few exoplanets that have been directly imaged, and it’s the first one in such an interesting dynamical configuration,” said Daniel Apai, an assistant professor of Astronomy and Planetary Sciences who leads a research group dedicated to finding and observing exoplanets at the UA.

“For about half of the planet’s orbit, which lasts 550 Earth-years, three stars are visible in the sky, the fainter two always much closer together, and changing in apparent separation from the brightest star throughout the year,” said Kevin Wagner, a first-year PhD student in Apai’s research group and the paper’s first author, who discovered HD 131399Ab. “For much of the planet’s year the stars appear close together, giving it a familiar night-side and day-side with a unique triple-sunset and sunrise each day. As the planet orbits and the stars grow further apart each day, they reach a point where the setting of one coincides with the rising of the other – at which point the planet is in near-constant daytime for about one-quarter of its orbit, or roughly 140 Earth-years.”

The orbit of the planet remains somewhat uncertain, and thus it might not be stable.

3 comments
1 … 102 103 104 105 106 … 188