Tag: astronomy

NASA estimates one month to address Webb vibration issues

9:27 am

NASA now expects it will take a month to assess and fix the issues uncovered during vibration testing of the James Webb Space Telescope.

Thomas Zurbuchen, the new head of NASA’s Science Mission Directorate (SMD), told SpacePolicyOnline.com that dealing with the problem likely will consume one of the remaining six months of schedule reserve.

No one at NASA has as yet explained exactly what the “anomalous readings” were during vibration testing. Nor did Zurbuchen indicate what the fix would be.

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Computer modeling suggests light fluctuations at Tabby’s Star are natural

10:16 am

A computer analysis of the light fluctuations of Tabby’s Star suggest to astronomers that the changes are not caused by objects blocking the star (such as an alien Dyson Sphere under construction) but are instead natural variations caused as the star evolves.

This conclusion is decidedly uncertain. They do not know the nature of this stellar evolution. And they are applying avalanche models to the star to come to this conclusion.

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Betelgeuse might have eaten a star

10:31 am

Because the red giant star Betelgeuse rotates far faster than it should, astronomers are now theorizing that when it expanded into its present red giant phase about 100,000 years ago it swallowed a companion star which contributed its own angular momentum to the system to speed up the rotation.

This theory is bolstered by evidence of a shell of matter surrounding Betelgeuse that is possibly a remnant of that destroyed star.

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Did a giant black hole eat a star?

10:45 am

New data now suggests that what astronomers had thought was the brightest supernova ever detect might have instead been the ripping apart of a star as it passed too close to a supermassive black hole.

In this scenario, the extreme gravitational forces of a supermassive black hole, located in the centre of the host galaxy, ripped apart a Sun-like star that wandered too close — a so-called tidal disruption event, something so far only observed about 10 times. In the process, the star was “spaghettified” and shocks in the colliding debris as well as heat generated in accretion led to a burst of light. This gave the event the appearance of a very bright supernova explosion, even though the star would not have become a supernova on its own as it did not have enough mass. The team based their new conclusions on observations from a selection of telescopes, both on the ground and in space. Among them was the NASA/ESA Hubble Space Telescope, the Very Large Telescope at ESO’s Paranal Observatory and the New Technology Telescope at ESO’s La Silla Observatory

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Scientists puzzle over possible connection between a fast radio burst and a gamma ray burst

9:31 am

The uncertainty of science: In trying to explain the relatively new mystery of fast radio bursts (FRB), of which only about 20 have been detected and of which very little is known, scientists are intrigued by a gamma ray burst (GRB) that apparently occurred at the same time and place of one FRB.

Seeing the FRB event in a different wavelength would normally help astronomers better understand the FRB The problem is that this particular GRB only makes the mystery of FRBs more baffling.

One puzzle is that the two signals portray different pictures of the underlying source, which seems to be as much as 10 billion light years (3.2 gigaparsecs) away. Whereas the radio burst lasted just a few milliseconds, the γ-ray signal lasted between two and six minutes, and it released much more energy in total than the radio burst. “We’ve pumped up the energy budget more than a billion times,” says study co-author Derek Fox, an astrophysicist at Penn State.

This has big implications for the FRB’s origin. One leading theory suggests that FRBs are flares from distant magnetars — neutron stars with enormous magnetic fields that could generate short, energetic blasts of energy, and do so repeatedly, as at least one FRB is known to do. Although magnetars are thought to produce γ-rays, they would not emit such high energy and over such a long time, says Fox. “This is a severe challenge for magnetar models,” he says.

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TMT legal case in Hawaii gets messier

7:02 pm

The permit process in Hawaii for the Thirty Meter Telescope has gotten far messier, with the telescope’s opponents appealing to the state’s Supreme Court, complaining about witness procedures and the lawyers who are working for the state, while the land board running the procedures has asked the court to dismiss this appeal.

Essentially, the opponents are using every trick in the book to delay the permit process, and it appears that the law in Hawaii, including one just passed in August, is designed to aid them in this tactic.

TMT will not be built in Hawaii.The consortium that is building it needs a decision by early next year at the latest. They ain’t gonna get it. The luddites going to win, and Hawaii will be far poorer because of it.

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Largest Texas meteorite ever found by accident on dude ranch

10:13 am

The largest Texas meteorite ever, weighing 760 pounds, has been found on a Texas dude ranch.

The owner found it entirely by accident. It apparently had been there for a long time, but no one had noticed it, mostly because of its weathered appearance that made it appear much like any other boulder. Tests proved beyond doubt, however, that it was a meteorite, an L4 chrondite. It has now been sold to a meteorite collection at Texas Christian University in Ft. Worth.

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Moon found orbiting one of the larger known Kuiper belt object

6:22 pm

Astronomers have found a moon circling 2007 Or10, one of the Kuiper Belts eight largest objects and the only one as yet unnamed.

Astronomers Gábor Marton and Csaba Kiss (Konkoly Observatory, Hungary), and Thomas MĂĽller (Max Planck Institute, Germany) have identified a moon orbiting 2007 OR10. They spotted it in Hubble Space Telescope images taken in September 2010 as part of a survey of trans-Neptunian objects. Marton announced the discovery this week at a joint meeting of the AAS’s Division for Planetary Sciences and the European Planetay Science Congress.

Although 2007 OR10 itself has been known for almost a decade, only recently have researchers realized that it’s surface is quite dark and therefore that it must be quite sizable, with an estimated diameter of 1,535 km (955 miles). This makes it the third-largest dwarf planet, after Pluto and Eris. It also ranks third for distance — 13 billion km or 87 astronomical units away — drifting among the stars of central Aquarius at a dim magnitude 21.

Of the eight largest Kuiper Belt objects, only Sedna has not yet been found to have a moon.

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Expansion rate of the universe might not be accelerating

6:06 pm

The uncertainty of science: A new review of the data suggests that the expansion of the universe might not be accelerating as posited based on research done in the 1990s.

Making use of a vastly increased data set – a catalogue of 740 Type Ia supernovae, more than ten times the original sample size – the researchers have found that the evidence for acceleration may be flimsier than previously thought, with the data being consistent with a constant rate of expansion.

The study is published in the Nature journal Scientific Reports.

Professor Sarkar, who also holds a position at the Niels Bohr Institute in Copenhagen, said: ‘The discovery of the accelerating expansion of the universe won the Nobel Prize, the Gruber Cosmology Prize, and the Breakthrough Prize in Fundamental Physics. It led to the widespread acceptance of the idea that the universe is dominated by “dark energy” that behaves like a cosmological constant – this is now the “standard model” of cosmology.

‘However, there now exists a much bigger database of supernovae on which to perform rigorous and detailed statistical analyses. We analysed the latest catalogue of 740 Type Ia supernovae – over ten times bigger than the original samples on which the discovery claim was based – and found that the evidence for accelerated expansion is, at most, what physicists call “3 sigma”. This is far short of the 5 sigma standard required to claim a discovery of fundamental significance.

I am not surprised. In fact, I remain continually skeptical about almost all cosmological theories. They might be the best we have, based on the facts available, but they are also based upon incredibly flimsy facts.

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TMT hearing a fiasco

8:00 pm

The initial hearing in Hawaii for the second permit application of the Thirty Meter Telescope today appears to have been a complete fiasco, designed to extend the proceedings as long as possible, ad infinitum.

Confusion reigned as Thursday’s hearing got underway in a Hilo hotel banquet room. Various telescope opponents complained about the scheduling and location of the hearing. One lawyer wanted to know the process for making objections. More than an hour went by before the first witness, environmental planner Perry White, was called to testify.

All witnesses will be allowed to provide a 10-minute summary of written testimony already submitted. But before White could provide his summary, there were various objections about qualifying him as an expert. Nearly two dozen people— many who are individual telescope opponents who don’t have lawyers representing them — will have a chance to cross-examine each witness.

Cross-examination of White will resume Monday.

It is very clear to me that Hawaii is stalling, designing the hearings so that they will last forever. TMT will never get built in Hawaii. It is time to say bye-bye and go somewhere where knowledge and technology is treasured.

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The clouds of hot Jupiter exoplanets

11:24 am

Exoplanet clouds

Cool image time! The image on the right, reduced to show here, provides an overall summary of what astronomers know about the atmospheres of many gas giant exoplanets that also orbit very close to their suns and are tidally locked. The view is of the planet hemisphere facing away from the star, which is also where most of the clouds are thought to be. These results come from Kepler data combined with computer modeling, and show what scientists thinks happens with different cloud compositions at different temperatures.

Link fixed!

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New object found beyond Kuiper belt

10:20 am

Worlds without end: Astronomers have discovered another object far beyond Pluto and in an elliptical orbit whose farthest point is 1,450 astronautical units, or about 135 billion miles from the Sun.

This is not the same object recently discovered in a somewhat similar elliptical orbit.

Astronomers right now do not understand the formation process that put these objects in these distant orbits. Some think the objects might have originally come from the Oort cloud that is even farther out from the Sun, their orbits shifted by the as-yet undiscovered Planet X that astronomers love to talk about, but others are skeptical. Since no one has ever actually detected anything in the the theorized Oort Cloud, it is also possible that it does not exist as presently theorized, and might actually be a more scattered collection of objects, like these new discoveries, that travel both farther and closer to the Sun.

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Ten times more galaxies than previously believed

9:44 am

The uncertainty of science: A new analysis from Hubble and other telescope data suggests that the universe actually contains ten times more galaxies than previously estimated, several trillion instead of the past estimate of 100 to 200 billion.

I would not bet much money on this conclusion. I suspect that further research will find even more galaxies, since our deep observations of the universe are at the moment confined to a mere handful of Hubble deep field images that cover only a few tiny specks of space.

This new analysis however did confirm previous estimates that suggest the universe has evolved and changed significantly over time.

In analysing the data the team looked more than 13 billion years into the past. This showed them that galaxies are not evenly distributed throughout the Universe’s history. In fact, it appears that there were a factor of 10 more galaxies per unit volume when the Universe was only a few billion years old compared with today. Most of these galaxies were relatively small and faint, with masses similar to those of the satellite galaxies surrounding the Milky Way.

These results are powerful evidence that a significant evolution has taken place throughout the Universe’s history, an evolution during which galaxies merged together, dramatically reducing their total number. “This gives us a verification of the so-called top-down formation of structure in the Universe,” explains Conselice.

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A large Kuiper Belt object discovered

3:55 pm

Astronomers have detected a new but very distant Kuiper Belt object.

For now, his team knows little more about their distant discovery other than its orbit and apparent brightness. Given its distance, however, the object should be sizable — anywhere from 400 km across (if its surface is bright and 50% reflective) to 1,200 km (if very dark and 5% reflective). If its true size edges toward the larger end of this range, then 2014 UZ224 would likely qualify for dwarf-planet status.

Fortunately, we should have a much better estimate of the object’s size very soon. Gerdes has used the ALMA radio-telescope array to measure the heat radiating from 2014 UZ224, which can be combined with the optical measurements to yield its size and albedo.

The object has a very eccentric 1,140 year orbit, coming as close to the sun as Pluto at its closest and almost five times farther away at its furthest.

Note: I have changed the article title because this new object is almost certainly not bigger the Pluto, as one of my readers pointed out.

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Green Bank goes private

9:01 am

The competition heats up: The Green Bank radio telescope in West Virginia, having lost most of its government funding, has switched to a private model where they compete for customers on the open market.

[T]hey petitioned to retain a fraction of NSF funding and make up the difference with private contracts—a model then unheard of. Eventually, the NSF agreed to fund about 60 percent of Green Bank’s operations in 2017, tapering to 30 percent in 2018.

To add cash flow to that federal tributary, Green Bankers had to nail down private contracts. The 140-foot telescope, home to the biggest ball bearing in the world, will download data from the Russian Space Agency’s on-orbit radio telescope, RadioAstron, which will also hook up with the newer telescope to form a high-resolution array. The North American Nanohertz Observatory for Gravitational Waves has commissioned the flagship Green Bank Telescope to watch their network of pulsars for fingerprints of gravitational waves.

And Breakthrough Listen—a search for extraterrestrial intelligence—will look for the technological fingerprints of aliens. The project, funded by rich-guy Yuri Milner, will watch the sky 1,300 hours a year, debiting $2 million from Milner annually and depositing it into Green Bank’s coffers.

In other words, they are marketing the telescope to the open market, selling time to use it to whoever has a need. And apparently, there is a need, though I suspect operations at the telescope will have to become leaner and meaner and more efficient to stay in the black. Which is to the good.

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Hawaii Supreme Court approves solar telescope construction

10:54 pm

Even as the Thirty Meter Telescope (TMT) on Mauna Kea remains in legal limbo, the Hawaii Supreme Court today ruled that the permits for the Daniel K. Inouye Solar Telescope on Haleakala were correct and that construction can go forward.

Not surprisingly, the protesters who have lost this case immediately indicated that they will fight it with continued protests, not unlike a 3-year-old who doesn’t get his way and starts to scream and yell and pound the floor.

Meanwhile, the TMT court case is supposed to resume later this month.

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The mystery of Tabby’s star deepens

7:07 am

Astronomers looking at the light variations of the star dubbed by some Tabby’s star have become even more baffled.

Spurred by a controversial claim that the star’s brightness gradually decreased by 14 percent from 1890 to 1989, Montet and Simon decided to investigate its behavior in a series of Kepler calibration images that had not previously been used for scientific measurements. “We thought that these data could confirm or refute the star’s long-term fading, and hopefully clarify what was causing the extraordinary dimming events observed in KIC 8462852,” explained Simon.

Simon and Montet found that, over the first three years of the Kepler mission, KIC 8462852 dimmed by almost 1 percent. Its brightness then dropped by an extraordinary 2 percent over just six months, remaining at about that level for the final six months of the mission. The pair then compared this with more than 500 similar stars observed by Kepler and found thata small fraction of them showed fading similar to that seen in KIC 8462852 over the first three years of Kepler images. However, none exhibited such a dramatic dimming in just six months, or a total change in brightness of 3 percent.

“The steady brightness change in KIC 8462852 is pretty astounding,” said Montet. “Our highly accurate measurements over four years demonstrate that the star really is getting fainter with time.  It is unprecedented for this type of star to slowly fade for years, and we don’t see anything else like it in the Kepler data.” 

At the moment, there is no good theory based on what astronomers know of stellar evolution to explain this star’s behavior. This does not mean the only explanation left is that aliens are building a Dyson sphere around the star, but it also leaves everyone at a loss to explain what is happening.

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Dark matter unnecessary?

9:06 pm

The uncertainty of science: A new analysis of the infrared data from 153 galaxies using the Spitzer Space Telescope suggests that dark matter might not be necessary to explain the rotation of galaxies.

First, this concise and nicely written explanation from the link of why dark matter has been proposed:

Newton’s laws of motion predict that planets that revolve closer to a star move faster than those that are farther away. In principle this should also hold true for stars circling the cores of galaxies, but for nearly a century, astronomers have seen that stars near the outskirts of galaxies orbit at nearly the same velocities as ones near galactic centers.

To explain why these outlying stars travel as quickly as they do without flying out into the void beyond, researchers came up with the idea of dark matter, a substance whose gravitational pull is thought to keep whirling stars in check. Scientists have largely ruled out all known particles as possible explanations for dark matter, and the consensus is that dark matter must be a kind of invisible, intangible material that is only detectable via its gravitational influence.

However, despite decades of trying, researchers have failed to capture a single mote of dark matter, even though it is supposed to make up roughly five-sixths of all matter in the universe. This raises the possibility that dark matter might not be real.

The new research, which I must admit I do not really understand, supposedly suggests that dark matter is unnecessary to explain the motions of stars.

Previous analyses of the orbital velocities of the stars in galaxies often depended on visible wavelengths of light. However, the stars that produce the most visible light are relatively short-lived and prone to fluctuations, and so may not provide the best picture of how matter is scattered overall throughout a galaxy. Instead, McGaugh and his colleagues analyzed near-infrared images collected by NASA’s Spitzer Space Telescope over the past five years. “The stars that generate the most near-infrared light are red giants, that are pretty stable in their output, and so are much better representative of a galaxy’s total mass of stars,” McGaugh said.

The researchers found an extraordinarily close association between the location of normal matter and the way it accelerates around the centers of galaxies. “We were surprised at how tight that relationship was,” McGaugh said. “It looks tantamount to a law of nature.”

Neither the article nor the scientists who did this research however explain clearly how this tight association negates the need for dark matter.

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Hubble captures on-going comet break-up

10:47 am

animation of comet debris

Cool image time! The animation to the right, taken over three days by the Hubble Space Telescope, cropped and reduced to fit here, shows the debris flying away from Comet 332P/Ikeya-Murakami. It also shows a new piece of debris close to the comet on the lower left.

The research team calculated that the comet probably shed material over several months, between October and December 2015. Jewitt suggests that even some of the ejected pieces have themselves fallen to bits in a kind of cascading fragmentation. “Our analysis shows that the smaller fragments are not as abundant as one might expect based on the number of bigger chunks,” he said. “This is suggestive that they’re being depleted even in the few months since they were launched from the primary body. We think these little guys have a short lifetime.”

Hubble’s sharp vision also spied a chunk of material close to the comet, which may be the first salvo of another outburst. The remnant from still another flare-up, which may have occurred in 2012, is also visible. The fragment may be as large as Comet 332P, suggesting the comet split in two. But the icy remnant wasn’t spotted until Dec. 31, 2015, by the Pan-STARRS (Panoramic Survey Telescope and Rapid Response System) telescope in Hawaii, in work supported by the Near-Earth Object Observations program in NASA’s Planetary Defense Coordination Office. That discovery prompted Jewitt and colleagues to request Hubble time to look at the comet in detail. Around the same time, astronomers around the world began to notice a cloudy patch of material near the comet – which Hubble later resolved into the 25 pieces.

The scientists think they actually “may be seeing a comet fragmenting itself into oblivion.”

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NASA extends Hubble contract through 2021

5:00 pm

NASA has extended its contract with Lockheed Martin for the operation of the Hubble Space Telescope until June 2021.

This contract is for non-science operations. Science operations are controlled by the Space Telescope Science Institute in Baltimore.

Note that when the last repair mission to Hubble took place in 2009, they expected it to add five years to the telescope’s life. This contract says they now expect it to last at least until 2021, which will also be 31 years after its launch and almost forty years since its actual construction. Not a bad track record when you think about it, especially since its original mission was set at 15 years, ending in 2005.

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Scientists discover exoplanets orbiting both stars of binary system

9:46 am

Worlds without end: Scientists have discovered a stellar binary system which has giant exoplanets orbiting each of the system’s stars.

The twin stars studied by the group are called HD 133131A and HD 133131B. The former hosts two moderately eccentric planets, one of which is, at a minimum, about 1 and a half times Jupiter’s mass and the other of which is, at a minimum, just over half Jupiter’s mass. The latter hosts one moderately eccentric planet with a mass at least 2.5 times Jupiter’s.

The two stars themselves are separated by only 360 astronomical units (AU). One AU is the distance between the Earth and the Sun. This is extremely close for twin stars with detected planets orbiting the individual stars. The next-closest binary system that hosts planets is comprised of two stars that are about 1,000 AU apart.

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New and very distance outer solar system objects beyond Neptune

10:11 am

Astronomers have discovered several new objects orbiting the Sun at extremely great distances beyond the orbit of Neptune.

The most interesting new discovery is 2014 FE72:

Another discovery, 2014 FE72, is the first distant Oort Cloud object found with an orbit entirely beyond Neptune. It has an orbit that takes the object so far away from the Sun (some 3000 times farther than Earth) that it is likely being influenced by forces of gravity from beyond our Solar System such as other stars and the galactic tide. It is the first object observed at such a large distance.

This research is being done as part of an effort to discover a very large planet, possibly as much as 15 times the mass of Earth, that the scientists have proposed that exists out there.

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More details about Proxima Centauri’s Earthlike exoplanet

8:50 am

Link here. Lots of background into the discovery itself, but I think these paragraphs really sum things up:

“The search for life starts now,” says Guillem Anglada-Escudé, an astronomer at Queen Mary University of London and leader of the team that made the discovery.

Humanity’s first chance to explore this nearby world may come from the recently announced Breakthrough Starshot initiative, which plans to build fleets of tiny laser-propelled interstellar probes in the coming decades. Travelling at 20% of the speed of light, they would take about 20 years to cover the 1.3 parsecs from Earth to Proxima Centauri.

Proxima’s planet is at least 1.3 times the mass of Earth. The planet orbits its red-dwarf star — much smaller and dimmer than the Sun — every 11.2 days. “If you tried to pick the type of planet you’d most want around the type of star you’d most want, it would be this,” says David Kipping, an astronomer at Columbia University in New York City. “It’s thrilling.”

The human race now has a real interstellar target to aim for. Don’t be surprised if we get there sooner than anyone predicts.

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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.

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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.

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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.

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