Tag: astronomy

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.”

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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Asteroid breaks in two, each piece develops a tail

2:08 pm

Astronomers have discovered a main belt asteroid that six years ago broke in two, after which both pieces developed tails resembling comets.

“The results derived from the evolution of the orbit show that the asteroid fragmented approximately six years ago, which makes it the youngest known asteroid pair in the Solar System to date,” says Fernando Moreno, researcher at the Institute of Astrophysics of Andalusia (IAA-CSIC), in charge of the project.

P/2016 J1 presents another important peculiarity, which makes it very unusual. “Both fragments are activated, i.e., they display dust structures similar to comets. This is the first time we observe an asteroid pair with simultaneous activity,” says Fernando Moreno (IAA-CSIC).

Analyses revealed that the asteroids were activated near their perihelion – the point on the orbit nearest to de Sun – between the end of 2015 and the beginning of 2016, and that they remained for a period of between six and nine months. The span of time between the moment of fragmentation and their bout of activity implies that the two events are not related. In fact, the data suggests that the fragmentation also happened near the perihelion but during the previous orbit (it takes P/2016 J1 5.65 years to spin around the Sun). “In all likelihood, the dust emission is due to the sublimation of ice that was left exposed after the fragmentation,” says Moreno (IAA-CSIC).

I suspect that the more we learn about asteroids and comets the more we will blur the line that separates them.

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A solar system of exoEarths!

1:53 pm

Astronomers have discovered a nearby solar system of exoplanets, all approximately Earth-sized with at least three in the habitable.

Following these initial findings, the star was systematically monitored to find out whether it contained any other planets. The result of this follow-up exceeded all expectations: TRAPPIST-1 has at least seven planets, all of which are Earth-sized (to within 15%). The six nearest planets (b to g) orbit their star in 1.5 to 12 days (the period of the seventh planet remains to be determined), and are 20 to 90 times closer to their star than the distance from the Earth to the Sun. At such distances, the tidal forces exerted by the star are considerable, locking the planets into synchronous rotation, which means that they rotate about their axis exactly once in one orbit, thus always showing the same face to their star (just as the Moon does relative to the Earth).

The planets of TRAPPIST-1 have insolations, and therefore average temperatures, similar to Earth’s: the insolation of the innermost planet (b) is slightly higher than that of Mercury, while the outermost planets (g and h) have an insolation that is a little lower than that of Mars. The insolations of at least three of the planets (e, f and g) are compatible with the existence of liquid water on their surface for a wide range of atmospheric compositions, as is shown by numerical simulations of their climate. Due to their synchronous rotation, it cannot be excluded that the planets with the highest irradiation (b, c and d) may harbor liquid water in temperate regions with little or no sunlight.

More here. The star, a cool dwarf, is only 40 light years away.

Posted in the Belize City airport, as we wait for our pickup.

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UC-Berkeley and Google looking for amateur images of upcoming August eclipse

9:48 am

In the hope of producing a long movie of the August eclipse that will cross the entire continental United States, the University of California-Berkeley and Google have teamed up to put together a project that will gather images taken by amateurs.

The Eclipse Megamovie Project is seeking more than a thousand amateur astronomers and avid photographers to record the Aug. 21 total solar eclipse and upload their photos to be stitched together into a movie documenting the path of totality from landfall in Oregon until the moon’s shadow slips over the Atlantic Ocean off South Carolina.

While no one on the ground will see the total eclipse for more than 2 minutes and 40 seconds, depending on how close they are to the center of the path of totality, the images collected by the Megamovie’s volunteer team will be turned into a 90-minute eclipse movie unlike anything seen before. Even an airplane flying along the path of totality can only capture at most a four- to five-minute movie, since the moon’s shadow moves along the ground at up to 1,500 miles per hour. The last time anyone tried to stitch together eclipse images like this may have been in the 1800s via hand-drawn sketches, without the benefit of today’s modern digital technology.

While I think this is a great idea, I must state my reservations about UC-Berkeley. This university is hostile to free speech, and actually encourages violence against conservatives who either attend the university or come to speak there. To work with it on this project would be a kind of endorsement of that behavior.

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A comet breaks apart

9:27 am

On February 12 members of the amateur astronomy organization Slooh actually viewed the break-up of Comet 73P/Schwassmann-Wachmann into two large fragments.

On the night of February 12th, Slooh members using the company’s telescopes in Chile were able to view the comet as it broke into two pieces. This seems to be the continuation of a process that was first witnessed in 1995, then again in 2006.

Slooh members were among the first to confirm that the nucleus of comet 73P/Schwassmann-Wachmann had split into at least two large pieces. “They immediately pointed Slooh’s telescopes to capture the event,” says Slooh Astronomer, Paul Cox. “Members will continue to monitor the comet live over the coming weeks – assuming the comet survives that long.”

They have created an animation from their images, but it appears that they only started taking images after the actual breakup, so the animation shows the two fragments, but not the moment they broke apart.

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Plotting the interstellar path to Proxima Centauri

8:40 am

Scientists have calculated the slingshot route that Breakthrough Starshot’s tiny interstellar spacecraft should take in order to reach Proxima Centauri while also gathering the maximum scientific data while zipping past the binary stars of Alpha Centauri.

The solution is for the probe’s sail to be redeployed upon arrival so that the spacecraft would be optimally decelerated by the incoming radiation from the stars in the Alpha Centauri system. René Heller, an astrophysicist working on preparations for the upcoming Exoplanet mission PLATO, found a congenial spirit in IT specialist Michael Hippke, who set up the computer simulations. The two scientists based their calculations on a space probe weighing less than 100 grams in total, which is mounted to a 100,000-square-metre sail, equivalent to the area of 14 soccer fields. During the approach to Alpha Centauri, the braking force would increase. The stronger the braking force, the more effectively the spacecraft’s speed can be reduced upon arrival. Vice versa, the same physics could be used to accelerate the sail at departure from the solar system, using the sun as a photon cannon.

The tiny spacecraft would first need to approach the star Alpha Centauri A as close as around four million kilometres, corresponding to five stellar radii, at a maximum speed of 13,800 kilometres per second (4.6 per cent of the speed of light). At even higher speeds, the probe would simply overshoot the star.

While most of this is hardly revolutionary, this is still the first time anyone has done the hard math based upon a real mission concept.

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New measurements of the universe’s expansion rate

3:41 pm

The uncertainty of science: New measurements of the universe’s expansion rate are apparently in agreement with some previous measurements but not with others.

The Hubble constant — the rate at which the Universe is expanding — is one of the fundamental quantities describing our Universe. A group of astronomers, the H0LiCOW collaboration, used the NASA/ESA Hubble Space Telescope and other telescopes in space and on the ground to observe five galaxies in order to arrive at an independent measurement of the Hubble constant. The new measurement is completely independent of — but in excellent agreement with — other measurements of the Hubble constant in the local Universe that used Cepheid variable stars and supernovae as points of reference.

…However, the value measured by Suyu and her team, as well as those measured using Cepheids and supernovae, are different from the measurement made by the ESA Planck satellite. But there is an important distinction — Planck measured the Hubble constant for the early Universe by observing the cosmic microwave background. While the value for the Hubble constant determined by Planck fits with our current understanding of the cosmos, the values obtained by the different groups of astronomers for the local Universe are in disagreement with our accepted theoretical model of the Universe.

Both measurements are very precise, but they do not match, suggesting that there are some basic fundamentals here that astronomers simply do not yet understand.

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