Tag: astronomy

Astronomers take best image of Betelgeuse yet

5:21 pm

Betelqeuse

Using the Atacama Large Millimeter/submillimeter Array Telescope (ALMA), astronomers have produced the best picture of the red giant star Betelgeuse taken so far.

Using ESO’s Very Large Telescope astronomers discovered a vast plume of gas almost as large as our Solar System. Astronomers have also found a gigantic bubble that boils away on Betelgeuse’s surface. These features help to explain how the star is shedding gas and dust at tremendous rates (eso0927, eso1121). In this picture, ALMA observes the hot gas of the lower chromosphere of Betelgeuse at sub-millimeter wavelengths — where localised increased temperatures explain why it is not symmetric.

The image on the right is that image, slightly reduced to post here. The bulge on the star’s left illustrates the unevenness of the star’s upper atmosphere. I suspect that continuous observations would reveal the outer atmosphere waxing and waning almost like the stuff inside a lava lamp.

2 comments

Astronomers discover complex molecules in protostar accretion disk

10:18 am

Astronomers have discovered several complex molecules in the accretion disk surrounding a very young baby star about 1300 light years away in the constellation Orion.

The research team’s ALMA observations have clearly detected an atmosphere of complex organic molecules above and below the disk. These include methanol (CH3OH), deuterated methanol (CH2DOH), methanethiol (CH3SH), and formamide (NH2CHO). These molecules have been proposed to be the precursors for producing biomolecules such as amino acids and sugars. “They are likely formed on icy grains in the disk and then released into the gas phase because of heating from stellar radiation or some other means, such as shocks,” says co-author Zhi-Yun Li of the University of Virginia.

What is even most interesting about this discovery is that these complex molecules are not scattered throughout the disk, but are concentrated in regions above and below its central plane, what the astronomers are labeling “an atmosphere.” This suggests that differentiation — the same process that separates the heavier molecules from lighter ones both in centrifuges and in the cores of planets — occurs quickly in accretion disks as well.

2 comments

Uranus’s magnetic field switches on and off daily

9:54 am

Using data from the Voyager 2 flyby of Uranus in 1986, scientists now think that the gas giant’s magnetic field switches on and off each day as the planet rotates.

Uranus’s magnetosphere, in contrast [to Earth], exhibits precise regularity in its mode changes. This, say the researchers, is because it lies at an angle of roughly 60 degrees to the planet’s spin axis, causing its interaction with incoming solar winds to vary dramatically during the 17 hours it takes for a full rotation. “Uranus is a geometric nightmare,” says Paty.

“The magnetic field tumbles very fast, like a child cartwheeling down a hill head over heels. When the magnetised solar wind meets this tumbling field in the right way, it can reconnect and Uranus’s magnetosphere goes from open to closed to open on a daily basis.”

The researchers suggest the robust and regular changes to the magnetosphere may mean that the icy planet has spectacular auroras across its breadth every day.

4 comments

Orbital motion of a binary black hole detected for the first time

10:19 am

Astronomers have for the first time measured the orbital motion of two supermassive black holes that orbit each other.

Based on the initial data, the two black holes appear to orbit each other every 30,000 years. Eventually, they will spiral into each other, merge, and in the process produce ripples in the surrounding gravitational field that will be detectable by future gravitational wave detectors.

Leave a comment

Update of Kepler exoplanet catalog

9:44 am

Worlds without end: The Kepler science team has released an update of the space telescope’s exoplanet candidate list, adding 219 new exoplanet candidates.

NASA’s Kepler space telescope team has released a mission catalog of planet candidates that introduces 219 new planet candidates, 10 of which are near-Earth size and orbiting in their star’s habitable zone, which is the range of distance from a star where liquid water could pool on the surface of a rocky planet. This is the most comprehensive and detailed catalog release of candidate exoplanets, which are planets outside our solar system, from Kepler’s first four years of data. It’s also the final catalog from the spacecraft’s view of the patch of sky in the Cygnus constellation.

With the release of this catalog, derived from data publicly available on the NASA Exoplanet Archive, there are now 4,034 planet candidates identified by Kepler. Of which, 2,335 have been verified as exoplanets. Of roughly 50 near-Earth size habitable zone candidates detected by Kepler, more than 30 have been verified.

Additionally, results using Kepler data suggest two distinct size groupings of small planets. Both results have significant implications for the search for life. The final Kepler catalog will serve as the foundation for more study to determine the prevalence and demographics of planets in the galaxy, while the discovery of the two distinct planetary populations shows that about half the planets we know of in the galaxy either have no surface, or lie beneath a deep, crushing atmosphere – an environment unlikely to host life.

34 comments

China launches X-ray space telescope

9:35 am

China today launched the Hard X-ray Modulation Telescope (HXMT), also dubbed Insight by Chinese news sources.

The HXMT carries three x-ray telescopes observing at energies ranging from 20 to 200 kilo-electron volts as well as an instrument to monitor the space environment, according to its designers. While orbiting 550 kilometers above the planet, the HXMT will perform an all-sky survey that is expected to discover a thousand new x-ray sources. Over an expected operating lifetime of 4 years, it will also conduct focused observations of black holes, neutron stars, and gamma ray bursts.

More here. This is China’s first home-grown X-ray space telescope, and its launch once again illustrates that, for at least the next few decades, China intends to be a major player in the exploration of the solar system.

Leave a comment

Design questions might delay construction of China’s first big optical telescope

9:03 am

A disagreement over the design of what China hopes would be, for a short while, the world’s largest optical telescope might delay that telescope’s construction.

On one side is an established engineering team, led by a veteran optics expert responsible for the nation’s largest existing telescope, that is eager to push ahead with an ambitious design. On the other are astronomers reveling in a grassroots priority-setting exercise—unprecedented for China—who have doubts about the ambitious design and favor something simpler.

Now, a panel of international experts has reviewed the designs and come out squarely in favor of the simpler proposal, according to a copy of the review obtained by Science. But the conclusion has not ended what one Chinese astronomer calls “an epic battle” between the high-ranking engineers accustomed to top-down control over projects and the nascent grassroots movement.

The telescope would have a mirror diameter of 12-meters, topping the 10.4 meter Gran Telescopio Canarias in the Canary Islands. To get it built in time to be the largest, they need to approve the construction plan by 2018.

The story is interesting in that is highlights the technical problems that exist for these large telescopes, most of which have had serious engineering issues that have limited their scientific output. The disagreement here is caused by an effort by some Chinese scientists to avoid these problems by using a simpler design.

Leave a comment

Astronomers confirm that comet caused Wow! signal, not aliens

9:01 am

Astronomers have confirmed that the Wow! signal, thought to be the most promising detection by SETI of alien life, was actually caused by a comet.

Last year, a group of researchers from the Center of Planetary Science proposed a new hypothesis that argued a comet might be the culprit. The frequency could be caused by the hydrogen cloud they carry, and the fact that they move accounts for why it seemingly disappeared. Two comets, named 266/P Christensen and P/2008 Y2 (Gibbs), happened to be transiting through that region of space when the Wow! signal was detected, but they weren’t discovered until after 2006.

To test the hypothesis, the team made 200 radio spectrum observations between November 2016 and February 2017. Sure enough, 266/P Christensen was found to emit radio waves at a frequency of 1,420 MHz, and to double check, the researchers moved their radio telescope by one degree. As expected, the signal vanished, and only returned when the telescope was trained back on the comet.

This story demonstrates once again why, in science, it is very dangerous to jump to any conclusions. The data we receive is a mystery. We must keep an open mind to solve that mystery.

5 comments

Jupiter gets two more moons

4:51 pm

Astronomers using ground-based telescopes have identified two more moon circling Jupiter, bringing its total now to 69.

Both of these discoveries, as with the vast majority of Jupiter’s moons, occupy retrograde orbits, with inclinations greater than 90°, meaning that they move in directions opposite that of the planet’s spin. These distant, irregular orbits imply that these bodies formed elsewhere in the outer solar system and were captured while passing by early in the planet’s history.

A number of the moons recently discovered have since been lost because their orbits were too poorly constrained. However, some of these lost moons have also be recovered.

9 comments

Exoplanet hotter than some stars

1:50 pm

Astronomers have identified an Jupiter-sized exoplanet with a surface that is apparently hotter than the surfaces of some stars.

With a day-side temperature of 4,600 Kelvin (more than 7,800 degrees Fahrenheit), planet KELT-9b is hotter than most stars, and only 1,200 Kelvin (about 2,000 degrees Fahrenheit) cooler than our own sun…. For instance, it’s a gas giant 2.8 times more massive than Jupiter but only half as dense, because the extreme radiation from its host star has caused its atmosphere to puff up like a balloon. And because it is tidally locked to its star—as the Moon is to Earth—the day side of the planet is perpetually bombarded by stellar radiation, and as a result is so hot that molecules such as water, carbon dioxide, and methane can’t form there. The properties of the night side are still mysterious—molecules may be able to form there, but probably only temporarily.

The most interesting aspect of this discovery is that it was done with small, inexpensive ground-based telescopes.

7 comments

More near Earth objects found by WISE

12:05 pm

NASA’s Wide-Field Infrared Explorer (WISE) has released its third year of survey data, including the discovery of 97 previously unknown objects.

Of those, 28 were near-Earth objects, 64 were main belt asteroids and five were comets. The spacecraft has now characterized a total of 693 near-Earth objects since the mission was re-started in December 2013.

For reasons that baffle me, NASA added “Near-Earth Object” to the telescope’s name when they restarted the mission, making its official name now NEOWISE.

4 comments

LIGO detects its third gravitational wave

8:22 am

LIGO scientists today revealed that the detector had spotted its third gravitational wave in January.

Researchers estimate that the bodies in the latest collision were slightly lighter than those in the first event: one had the mass of 31 Suns and the other 19. (The black holes in the second discovery were even more lightweight, at 14 and 8 solar masses.) But the latest merger is the most distant detected so far. The gravitational waves it produced took somewhere between 1.6 billion and 4.3 billion years to reach Earth — most probably around 2.8 billion years.

This new field of astronomy should get even more interesting in the next year or two, as new detectors come on line in Italy and Japan.

One comment

If TMT moves from Hawaii Canada might exit partnership

11:32 am

The possibility that the Thirty Meter Telescope might be forced to move from Hawaii to the Canary Islands because of political opposition in Hawaii has Canadian scientists considering leaving the partnership.

The mega-telescope is “a critical component of the Canadian astronomical landscape,” says Michael Balogh, an astronomer at the University of Waterloo in Ontario. The country — one of six major international partners — has committed CAN$243 million (US$180 million) to the project. “If we have to move, it’s effectively a de-scope in the project,” says Balogh.

The back-up site, Roque de los Muchachos in La Palma, the Canary Islands, is lower in elevation than Mauna Kea, and its skies are more turbulent than those above the Hawaii mountain. That means that observing conditions are not quite as good; in particular, the extra atmosphere above La Palma interferes with much of the observing in mid-infrared wavelengths of light, the sweet spot for looking at exoplanet atmospheres.

If Canada leaves, there is a chance that the entire TMT partnership might fall apart.

One comment

Astronomers find star with giant ringed planet

9:30 am

Astronomers now think that a sunlike star about 1,000 light years away dips in brightness every 2.5 years because an orbiting ringed planet or ringed dwarf star blocks the star’s light.

They discovered that every two and a half years, the light from this distant star – PDS 110 in the Orion constellation, which is same temperature and slightly larger than our sun – is reduced to thirty percent for about two to three weeks. Two notable eclipses observed were in November 2008 and January 2011. “What’s exciting is that during both eclipses we see the light from the star change rapidly, and that suggests that there are rings in the eclipsing object, but these rings are many times larger than the rings around Saturn,” says Leiden astronomer Matthew Kenworthy.

Assuming the dips in starlight are coming from an orbiting planet, the next eclipse is predicted to take place in September this year – and the star is bright enough that amateur astronomers all over the world will be able to witness it and gather new data. Only then will we be certain what is causing the mysterious eclipses.

If confirmed in September, PDS 110 will be the first giant ring system that has a known orbital period. [emphasis in original]

Just so no one is confused, this is not Tabby’s Star. There, the dips in light are seemingly random and follow no pattern, other than an overall dimming for the past century.

2 comments

Construction begins on the European Extremely Large Telescope

10:47 am

On Friday the European Southern Observatory broke ground in Chile on the construction of the European Extemely Large Telescope (E-ELT), which when finished in 2024 will be the largest ground-based telescope in the world.

The mirror will be 39 meters across.

Meanwhile, construction of the Thirty Meter Telescope remains stalled. It was originally supposed to be operating before E-ELT, but that is becoming increasingly doubtful. Its builders can’t get Hawaii to approve a building permit, and they haven’t yet been willing to admit that they will never get permission to build there.

3 comments

Star becomes black hole without supernova explosion

10:20 am

The uncertainty of science: Astronomers think they have identified a star that, rather than die and become a black hole in a supernova explosion, merely fizzled into a black hole.

Starting in 2009, one particular star in the Fireworks Galaxy, named N6946-BH1, began to brighten weakly. By 2015, it appeared to have winked out of existence. The astronomers aimed the Hubble Space Telescope at the star’s location to see if it was still there but merely dimmed. They also used the Spitzer Space Telescope to search for any infrared radiation emanating from the spot. That would have been a sign that the star was still present, but perhaps just hidden behind a dust cloud.

All the tests came up negative. The star was no longer there. By a careful process of elimination, the researchers eventually concluded that the star must have become a black hole.

There are a lot of uncertainties here. Nonetheless, astronomers have theorized that some stars could collapse into black holes with any explosions, and it appears they might have found their first example of that.

6 comments

Moon discovered around Kuiper belt dwarf planet

11:28 am

Astronomers have discovered a moon orbiting 2007 OR10, one of the Kuiper Belt’s larger objects.

With this discovery, most of the known dwarf planets in the Kuiper Belt larger than 600 miles across have companions. These bodies provide insight into how moons formed in the young solar system. “The discovery of satellites around all of the known large dwarf planets — except for Sedna — means that at the time these bodies formed billions of years ago, collisions must have been more frequent, and that’s a constraint on the formation models,” said Csaba Kiss of the Konkoly Observatory in Budapest, Hungary. He is the lead author of the science paper announcing the moon’s discovery. “If there were frequent collisions, then it was quite easy to form these satellites.”

Leave a comment

New multi-wavelength image of Crab Nebula

12:00 pm

Crab Nebula

Cool image time! The image on the right, reduced and cropped to show here, was created in November 2012 using a number of different telescopes, both on the ground and in space, to image the Crab Nebula in as much of the entire electromagnetic spectrum as possible.

This image combines data from five different telescopes: The VLA (radio) in red; Spitzer Space Telescope (infrared) in yellow; Hubble Space Telescope (visible) in green; XMM-Newton (ultraviolet) in blue; and Chandra X-Ray Observatory (X-ray) in purple.

Be sure to check out the full image at the Hubble website. It is packed with fascinating details you need to zoom in to to see.

2 comments

Astronomers find that Epsilon Eridani solar system resembles our own system

1:28 pm

New data of the Epsilon Eridani solar system 10.5 light years away confirms that its debris disk has a structure somewhat resembling our own solar system.

The data has found that the debris disk has two narrow belts, one located at about the same distance from the star as our asteroid belt, and the other orbiting at about where Uranus is located. In addition, the system appears to have a Jupiter-sized planet orbiting the same distance from the star as does Jupiter.

8 comments

Latch blamed for Webb vibration test issue

6:03 pm

A latch that hadn’t closed properly has been identified as the cause of the anomaly that halted vibration testing of the James Webb Space Telescope in December.

At the committee meeting, Smith said the problem was tracked down to a latch designed to hold in place one of the wings of JWST’s primary mirror, which consists of 18 hexagonal segments. Those wings are folded into place to fit within the payload fairing of the Ariane 5 that will launch JWST, then deployed into place once in space. The latch, he said, consists of two plates with serrated teeth a few millimeters in size. “The thought is that the teeth, when they closed it, they didn’t quite seat,” he said. “So during the vibe [test], the teeth clapped together on the order of a millimeter or two, and that was what made the noise.”

Engineers were able to replicate the noise by placing the plates slightly out of alignment in the lab and subjecting them to similar vibrations, giving them confidence that was the cause of the anomaly.

I love how the Webb program manager also says that Webb is “on budget and on schedule.” That claim could only be true if you make believe that the budget was always $9 billion and the launch date was always supposed to be 2018 instead of the original $1 billion and 2011 launch date.

4 comments

First results from Breakthrough Listen’s search for alien radio signals

3:44 pm

Breakthrough Listen has released its first results from its search for extraterrestrial radio signals using the Greenbank Observatory in West Virginia.

Breakthrough Listen – the initiative to find signs of intelligent life in the universe – has released its 11 events ranked highest for significance as well as summary data analysis results. It is considered unlikely that any of these signals originate from artificial extraterrestrial sources, but the search continues. Further, Listen has submitted for publication (available April 20) in a leading astrophysics journal the analysis of 692 stars, comprising all spectral types, observed during its first year of observations with the Green Bank Telescope.

The press release tries to make a big deal about this data, but essentially what it boils down to is that so far they have found nothing that could indicate artificial radio signals coming from any of these stars.

Leave a comment

New poll says most Hawaiians favor TMT

5:53 pm

It won’t matter: A new poll suggests that a large majority of Hawaiians strongly favor the construction of the Thirty Meter Telescope (TMT) on Mauna Kea on Hawaii’s Big Island.

When it comes to the Thirty Meter Telescope atop Mauna Kea, 72 percent of likely voters said they supported it. On the Big Island, 68 percent of residents said they favored it, 15 percent more than two years ago.

“Even on Hawaii Island, support is over 2-to-1 that this is a project that they don’t want to see an opportunity lost for local kids there,” said Kyle Chock, interim executive director of Pacific Resource Partnership, which conducted the poll.

I am not surprised by this poll. Nor do I think it makes a bit of difference. I right now do not believe TMT will be built on Hawaii. The state government, controlled by the Democratic Party, is entirely sympathetic to the position of the small minority that is hostile to this project. This minority is opposed mostly because of a bigoted dislike of non-natives and a close-minded ignorance of modern technology. And because today’s Democratic Party cares only for racial and ethnic minorites, it supports them entirely. That government has been slow-walking the permitting process so much that it will decades to get through it.

Posted about 36,000 feet in the air over Hungary, returning from my week-long visit to Israel.

Leave a comment

Citizen scientists crowd scource discovery of 4 exoplanets

9:05 am

After being promoted on an Australian tv show an effort to use public help to plow through Kepler’s vast archives discovered four new exoplanets within two days.

In three days, the Australia iteration of astronomy TV show Stargazing Live brought us #SpaceGandalf and now its viewers have discovered four planets. After it was promoted on the show, citizen scientists and fans of the program came together to contribute to a crowd-sourcing project, stalking around 100,000 stars on the Zooniverse website, which displays recent data from the Kepler Space Telescope.

And you betcha, in just 48 hours, around 10,000 volunteers discovered scores of potential new planet candidates, with scientists confirming the discovery of four “super-Earth” planets orbiting a star in the constellation of Aquarius.

Leave a comment

Atmosphere detected around Earth-sized exoplanet

9:00 am

Worlds without end: Astronomers have detected an atmosphere around an Earth-sized exoplanet 39 light years away.

The researchers pored over measurements from the European Southern Observatory in Chile and found that at one wavelength band of light, the planet looked larger than at others, as it crossed the face of its parent star. “These things don’t pop up in the way you expect,” said John Southworth, an astronomer at Keele University in the UK. “We found evidence for the atmosphere at one wavelength band and that wasn’t what we were expecting.”

The observations point to an atmosphere that is rich in water or methane, but it will take more measurements with other telescopes to identify the chemicals present.

The planet is about 16% larger than Earth. There remain a lot of uncertainty here with this result, so we should not yet take it too seriously.

One comment

Hubble snaps close-up of Jupiter

4:08 pm

Jupiter by Hubble

Cool image time! The Hubble Space Telescope has taken a magnificent global view of Jupiter. The image on the right is only a thumbnail. Make sure to go to the link to see the full image, which amazingly compares quite favorably with the images being sent down by Juno in orbit around the gas giant.

This Hubble image once again demonstrates the remarkable advantages of an optical telescope in space. Equipped with the right instruments, it could do much of the research now being done by the planetary missions, and do it from Earth orbit.The research possibilities and the knowledge revealed from the ability to see things clearly in the optical bands is truly endless.

Even more important, we are wired to what we see. Give us a good visual image and many questions can immediately be answered.

4 comments

New theory eliminates need for dark energy

9:09 am

The uncertainty of science: A new theory now shows that dark energy, the apparent acceleration of the universe’s expansion rate on large scales, does not need to exist in order to explain the data that astronomers have obtained.

In the new work, the researchers, led by Phd student Gábor Rácz of Eötvös Loránd University in Hungary, question the existence of dark energy and suggest an alternative explanation. They argue that conventional models of cosmology (the study of the origin and evolution of the universe), rely on approximations that ignore its structure, and where matter is assumed to have a uniform density. “Einstein’s equations of general relativity that describe the expansion of the universe are so complex mathematically, that for a hundred years no solutions accounting for the effect of cosmic structures have been found. We know from very precise supernova observations that the universe is accelerating, but at the same time we rely on coarse approximations to Einstein’s equations which may introduce serious side-effects, such as the need for dark energy, in the models designed to fit the observational data.” explains Dr László Dobos, co-author of the paper, also at Eötvös Loránd University.

In practice, normal and dark matter appear to fill the universe with a foam-like structure, where galaxies are located on the thin walls between bubbles, and are grouped into superclusters. The insides of the bubbles are in contrast almost empty of both kinds of matter. Using a computer simulation to model the effect of gravity on the distribution of millions of particles of dark matter, the scientists reconstructed the evolution of the universe, including the early clumping of matter, and the formation of large scale structure.

Unlike conventional simulations with a smoothly expanding universe, taking the structure into account led to a model where different regions of the cosmos expand at different rate. The average expansion rate though is consistent with present observations, which suggest an overall acceleration.

In other words, the uneven structure of the universe has never been considered in previous models, and once included in the equations the need for dark energy disappears.

8 comments

Less evidence of dark matter in early universe

10:49 pm

The uncertainty of science: Astronomers have discovered less evidence of dark matter surrounding galaxies in early universe.

Stars in the outer regions of some far-off galaxies move more slowly than stars closer to the center, indicating a lack of dark matter, astronomer Reinhard Genzel and colleagues report online March 15 in Nature. If confirmed, the result could lead astronomers to reconsider the role dark matter played in early galaxy evolution and might also offer clues to how nearby elliptical galaxies evolved.

In contrast with these distant galaxies, stars orbiting on the outskirts of the Milky Way and other nearby galaxies move too fast for their velocities to result only from the gravity of gas and stars closer to the galactic center. If visible galactic matter is embedded in a cloud of invisible dark matter, though, gravity from the invisible matter can explain the high stellar velocities. Using stars’ orbital velocities in nearby galaxies as a reference, astronomers expected that stars in galaxies farther away would behave similarly. “Turns out that is not the case,” says study coauthor Stijn Wuyts of the University of Bath in England.

In other words, scientists at this moment really have no idea what causes the faster rotation in the outskirts of modern nearby galaxies.

17 comments

44 days for first round of hearings on TMT

7:32 pm

Stonewalling: Hawaiian officials have just completed the first round of hearings for deciding whether to issue a new construction permit for building the Thirty Meter Telescope, and those hearings stretched out for 44 days and cost nearly $225K.

Will that allow for a new permit? Don’t bet on it.

The hearings officer will recommend whether the state land board should grant a construction permit for the Thirty Meter Telescope. If there are exceptions filed to the hearings officer’s recommendations, the land board will hear arguments before issuing a written decision.

In other words, the state will allow the telescope’s opponents to force another set of hearings that could likely last as long.

As I’ve said before, it is time to tell Hawaii to go to hell. The state, run by Democrats, is obviously taking sides in opposition to the telescope, though they are trying to hide that fact. If the consortium wants to build this telescope on time, they need to find a place interested in having them. Let Hawaii keep its barren and empty mountain, even if it means the state will be poorer and less connected with the cutting edge of science.

4 comments
1 … 34 35 36 37 38 … 72