Tag: astronomy

New Hubble image of Crab Nebula

9:42 am

Crab Nebula

Cool image time! Scientists have released a new Hubble Space Telescope image taken of the innermost regions of the Crab Nebula, the remains of a supernova explosion that took place a thousand years ago in 1054.

On the right is a reduced resolution version of this new image. I have also cropped it to focus on the nebula’s center, where the pulsar is located. The circular concentric rings are exactly what they appear to be, ripples of energy spreading out from the pulsar. Back in 2002 Hubble took a series of images of the Crab Nebula over several days, which scientists then assembled into a movie showing these waves as they emanated out from the nebula’s center.

My only complaint with this beautiful new image is that they did not take a longer series of new exposures to create a longer movie, to better show the actual daily changes that the nebula undergoes. It seemed obvious to do then, and obvious to do now. Yet, it hasn’t happened.

The image download page for today’s release is here.

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Hubble images Jupiter and its aurora

9:03 am

Jupiter and its aurora

Cool image time! In anticipation of the arrival of Juno in orbit around Jupiter on July 4, scientists have released a spectacular image of Jupiter and its aurora, taken by the Hubble Space Telescope. The image on the right has been reduced slightly to fit on the webpage.

The main focus of the imaging is the aurora.

To highlight changes in the auroras, Hubble is observing Jupiter almost daily for several months. Using this series of far-ultraviolet images from Hubble’s Space Telescope Imaging Spectrograph, it is possible for scientists to create videos that demonstrate the movement of the vivid auroras, which cover areas bigger than the Earth.

Not only are the auroras huge in size, they are also hundreds of times more energetic than auroras on Earth. And, unlike those on Earth, they never cease. While on Earth the most intense auroras are caused by solar storms — when charged particles rain down on the upper atmosphere, excite gases, and cause them to glow red, green, and purple — Jupiter has an additional source for its auroras.

The strong magnetic field of the gas giant grabs charged particles from its surroundings. This includes not only the charged particles within the solar wind, but also the particles thrown into space by its orbiting moon Io, known for its numerous and large volcanos.

I have embedded below the fold one of the videos of the aurora, taken over time by Hubble. Quite amazing.
» Read more

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Moon discovered orbiting Kuiper Belt Object Makemake

6:57 pm

Worlds without end: Astronomers have discovered a moon orbiting Makemake, the fouth largest object in the Kuiper Belt.

A nearly edge-on orbital configuration helped it evade detection, placing it deep within the glare of the icy dwarf during a substantial fraction of its orbit. Makemake is one of the largest and brightest known Kuiper Belt Objects (KBOs), second only to Pluto. The moon is likely less than 100 miles wide while its parent dwarf planet is about 870 miles across. Discovered in 2005, Makemake is shaped like football and sheathed in frozen methane.

Tracking this moon’s orbit will help astronomers get a better understanding of Makemake itself, whose oblong shape has baffled them since its discovery.

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Newly discovered asteroid quasi-moon of Earth

11:41 pm

A newly discovered asteroid has a solar orbit that makes it Earth’s constant companion.

As it orbits the sun, this new asteroid, designated 2016 HO3, appears to circle around Earth as well. It is too distant to be considered a true satellite of our planet, but it is the best and most stable example to date of a near-Earth companion, or “quasi-satellite.”

“Since 2016 HO3 loops around our planet, but never ventures very far away as we both go around the sun, we refer to it as a quasi-satellite of Earth,” said Paul Chodas, manager of NASA’s Center for Near-Earth Object (NEO) Studies at the Jet Propulsion Laboratory in Pasadena, California. “One other asteroid — 2003 YN107 — followed a similar orbital pattern for a while over 10 years ago, but it has since departed our vicinity. This new asteroid is much more locked onto us. Our calculations indicate 2016 HO3 has been a stable quasi-satellite of Earth for almost a century, and it will continue to follow this pattern as Earth’s companion for centuries to come.”

The asteroid is thought to be between 120 to 300 feet across.

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National Science Foundation considers shuttering Arecibo

9:33 am

Faced with tight budgets, the National Science Foundation (NSF) is considering several options for the future operation of the Arecibo Observatory, the world’s largest single radio telescope dish, including its complete removal.

[T]he NSF could mothball the site, shutting it down in such a way that it could restart (sometime in the future). Or it could dismantle the telescope altogether and restore the area to its natural state, as required by law if the agency fully divests itself of the observatory and closes it. Previous studies have said such a process could cost around $100 million—more than a decade’s worth of its current funding for telescope operations. Jim Ulvestad, director of the NSF Division of Astronomical Sciences, says the agency is still investigating, not concluding. “No alternative has been selected at this juncture,” he says. And much consideration will go into the final financial decision, whatever it may be. Some outside the agency see writing on the wall. “NSF is dead serious about offloading Arecibo funding to someone else—anyone else,” says Ellen Howell, a former staff scientist at Arecibo and now a faculty member at the Lunar and Planetary Laboratory (LPL) in Tucson, Arizona.

The article spends a lot of time talking about how wonderful Arecibo is, but never tells us how many astronomers actually demand to use it. Is it oversubscribed, like Hubble, where five times the number of astronomers request time than can be handled, or does it often sit unused because not enough astronomers require its use? NSF and the government do not have unlimited funds, and need to focus their spending where the demand is. If Arecibo is not in demand, then they are wise to consider closing it, or handing it off to someone who wants it.

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LISA Pathfinder proves space-based gravity wave detection technology

8:43 am

Engineers have announced that the gravity wave detection technology being tested in orbit by Europe’s LISA Pathfinder works.

To show that the necessary sensitivity is possible, LISA Pathfinder measures the distance between two masses, both of which are inside the spacecraft. “We’ve shrunk the arm of a large gravitational wave antenna to 35 centimeters so we could show it works properly,” Paul McNamara, LISA Pathfinder project scientist, told the press conference.

LISA Pathfinder was launched in December 2015 to a spot 1.5 million kilometers from Earth. When its test masses where first released to float free in February, “the relief was unbelievable,” McNamara says. Science operations began on 1 March and on that first day the team was able to measure distance variations between the masses much smaller than LISA Pathfinder’s mission requirements, Stefano Vitale, the mission’s principle investigator, told reporters. After a month, the variations were even smaller, “very close to [eLISA] requirements,” he says.

They now hope to launch an array of at least three such spacecraft by the mid-2030s.

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Titan over Saturn’s rings

9:35 am

Titan over Saturn's rings

Cool image time! The picture on the right, taken on January 26, 2016 by Cassini and reduced and cropped to show here, captures Titan above Saturn’s rings, which are themselves partly obscured by the shadow of Saturn (unseen on the right) that falls across them.

Make sure you go to look at the full image. This is the kind of vista that artists in the 1950s imagined we’d see once we began to explore the solar system.

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Hawaii turns down requests to remove TMT hearings officer

9:10 am

The state of Hawaii has decided to not replace the hearings officer in charge of the new permitting process for the Thirty Meter Telescope, despite a request by TMT to remove her.

There are different reasons for wanting to replace her. Telescope opponents raise conflict-of-interest concerns over her paid family membership to the Imiloa Astronomy Center. The university takes issue with her mediating another matter involving the Manoa campus. The nonprofit telescope company says replacing her with an alternate would avoid further delay.

“With due respect and consideration to the parties’ various interests and reasons for asking the board to replace Judge Amano, the board cannot and will not sidestep its own administrative responsibility to exercise judgment and common sense regarding whether the selection process up until now has objectively appeared to be fair,” the order said. “Common sense must prevail.”

The situation is a strange one. Despite the fact that the judge would likely rule fairly, TMT wanted her removed because they expect their opponents to eventually dispute any favorable decision she makes because of her link to the astronomy center. By refusing to remove her, the state is actually taking the side of the telescope’s opponents, since their main tactic is delay.

I hope TMT’s builders are making serious plans for finding an alternative site. I do not expect them to ever get permission to build in Hawaii.

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New data challenges consensus on galaxy formation

8:54 am

The uncertainty of science: A new study has found that the accepted consensus for the formation of large elliptical galaxies does not work, and that, rather than forming from the merger of smaller spiral galaxies, ellipticals formed in place from the material at hand.

From the press release [pdf].

“We started from the data, available in complete form only for the closer galaxies and in incomplete form for the more distant ones, and we filled the ‘gaps’ by interpreting and extending the data based on a scenario we devised” comments Mancuso. The analysis also took into account the phenomenon of gravitational lensing, which allows us to observe very distant galaxies belonging to ancient cosmic epochs.

In this “direct” manner (i.e., model-independent) the SISSA group obtained an image of the evolution of galaxies even in very ancient epochs (close, in a cosmic timescale, to the epoch of reionization). This reconstruction demonstrates that elliptical galaxies cannot have formed through the merging of other galaxies, “simply because there wasn’t enough time to accumulate the large quantity of stars seen in these galaxies through these processes”, comments Mancuso. “This means that the formation of elliptical galaxies occurs through internal, in situ processes of star formation.

The important take-away of this result is that it shows that the present theory of galaxy formation, where smaller spiral galaxies merge to form larger elliptical galaxies, does not fit the data. And if a theory does not fit the data, it must be abandoned.

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Jupiter exoplanet around baby star

10:38 am

The uncertainty of science: Astronomers have discovered a Jupiter-class exoplanet orbiting a very young star, something their models of planetary formation told them shouldn’t happen.

“For decades, conventional wisdom held that large Jupiter-mass planets take a minimum of 10 million years to form,” said Christopher Johns-Krull, the lead author of a new study about the planet, CI Tau b, that will be published in The Astrophysical Journal. “That’s been called into question over the past decade, and many new ideas have been offered, but the bottom line is that we need to identify a number of newly formed planets around young stars if we hope to fully understand planet formation.”

CI Tau b is at least eight times larger than Jupiter and orbits a 2 million-year-old star about 450 light years from Earth in the constellation Taurus.

In other words, a planet that, according to the present models for planetary formation, supposedly needs 10 million years to form is orbiting a star only 2 million years old. In other words, the models are wrong. We simply don’t know enough yet about planetary formation to create any reliable models.

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TMT calls for removal of official supervising permit process

9:00 am

The University of Hawaii has filed a motion to have the hearing officer in charge of the new permitting process for the Thirty Meter Telescope (TMT) removed.

What the lawyers for TMT appear to be doing is trying to prevent further delaying tactics by those opposing the telescope. Their motion describes these delaying tactics, which involve questioning the objectivity of various officials involved, but doing it piecemeal in order to slow the permitting process down as much as possible. The officer in question has membership in an astronomy center, and though the anti-TMT forces have not yet questioned this, TMT lawyers want to act now to remove that possibility later.

Once again, I think TMT officials are spinning their wheels. Hawaii will never give them permission to build TMT. Read the ten-point plan of Hawaii’s governor for protecting Mauna Kea and you will agree. They should move the telescope to a more friendly location as soon as possible.

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ESO signs giant telescope contract

9:06 am

The European Southern Observatory today signed the contract to begin building the European Extremely Large Telescope (E-ELT).

The contract covers the design, manufacture, transport, construction, on-site assembly and verification of the dome and telescope structure. With an approximate value of 400 million euros, it is the largest contract ever awarded by ESO and the largest contract ever in ground-based astronomy. The E-ELT dome and telescope structure will take telescope engineering into new territory. The contract includes not only the enormous 85-metre-diameter rotating dome, with a total mass of around 5000 tonnes, but also the telescope mounting and tube structure, with a total moving mass of more than 3000 tonnes. Both of these structures are by far the largest ever built for an optical/infrared telescope and dwarf all existing ones. The dome is almost 80 metres high and its footprint is comparable in area to a football pitch.

The E-ELT is being built on Cerro Armazones, a 3000-metre peak about 20 kilometres from ESO’s Paranal Observatory. The access road and leveling of the summit have already been completed and work on the dome is expected to start on site in 2017.

E-ELT will have a main mirror 39 meters in width, about 9 meters bigger than the stalled TMT project.

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TMT permitting process about to begin anew

9:38 pm

The retired Hawaiian judge who will supervise the new permitting process for the Thirty Meter Telescope held a prelminary meeting on Monday to discuss scheduling and procedual matters.

The Hawaiian authorities have been slow-walking this new permiting process, which the telescope already completed according to law years ago. I say TMT should just leave Hawaii so its citizens can enjoy their barren mountain and the lack of jobs and wealth it will bring them.

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New analysis says it ain’t aliens at strange star

2:17 pm

The uncertainty of science: A new analysis of old star data has concluded that KIC 8462852, also known Tabby’s Star and subject to random fluctuations that no scientist can explain, has not dimmed by 20% in the past century.

This reduces the chances that the fluctuations are caused by the slow accumulating construction of a Dyson sphere by an alien civilization, as some have proposed, but it still does nothing to explain the star’s random changes in brightness.

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Exoplanets found nearby

5:26 pm

Worlds without end: Astronomers have identified three planets close to the habitable zone on a star only 39 light years away.

A year on the two inner planets lasts just a couple of days. Data on the third world are sparse; it could take anywhere between 4.5 and 72.8 days to trek around its sun. The star, designated 2MASS J23062928−0502285, is roughly the size of Jupiter — about one-tenth as wide as our sun — and about 3,200 degrees Celsius cooler than the sun. Such runts make up about 15 percent of the stars in the galaxy, though astronomers had not found planets around one before. All three planets were discovered as periodic dips in starlight in late 2015 using TRAPPIST, a telescope at La Silla Observatory in Chile.

If anything does crawl or grow on these worlds, it bathes in mostly infrared light. The innermost planets receive several times as much energy from their star as Earth does from our sun, which technically puts them outside the star’s habitable zone (SN: 4/30/16, p. 36). But the planets are huddled up so close to the star that gravity might keep them from spinning, creating a temperate zone along the line where day turns to night, the researchers suggest.

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Hubble discovers moon circling Kuiper belt object

10:10 am

Worlds without end: Hubble has spotted a small moon orbiting the distant Kuiper Belt object Makemake.

The moon — provisionally designated S/2015 (136472) 1 and nicknamed MK 2 — is more than 1,300 times fainter than Makemake. MK 2 was seen approximately 13,000 miles from the dwarf planet, and its diameter is estimated to be 100 miles across. Makemake is 870 miles wide. The dwarf planet, discovered in 2005, is named for a creation deity of the Rapa Nui people of Easter Island.

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New Hubble image of Red Rectangle

9:13 am

The Red Rectangle

Cool image time! I think the Red Rectangle might be my favorite planetary nebula. The new image on the right, taken by the Hubble Space Telescope, is the best yet of this weirdly shaped object. And it continues to suggest, as I noted whimsically in an article about it for Sky & Telescope back in November 2014, that this is a web being spin by the universe’s largest spider.

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Funds needed to identify “Wow!” signal

9:52 am

An astronomer who thinks the “Wow!” radio signal was not from aliens but caused by two comets that were not known at the time is trying to crowd-source the funds he needs to obtain radio telescope time to prove his theory.

Comet 266P/Christensen will pass the Chi Sagittarii star group again on 25 January 2017, while 335P/Gibbs will make its passage on 7 January 2018. Paris plans to observe these events to look for a recurrence of the mystery signal. But time is not on his side for using an existing radio telescope – they are all booked out.

So, he has launched a crowdfunding campaign on gofundme to raise the $13,000 he needs to buy a radio telescope to make the observation. Donations are rolling in and he is already most of the way to his target. “I would like to [be fully funded] in May, order the stuff so that I can have it by October,” he says. This would give him time to construct the dish, test it and prepare for the January encounter.

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Universe’s expansion rate contradicts dark energy data

8:42 am

The uncertainty of science: New measurements of the universe’s expansion rate, dubbed the Hubble constant, contradict theoretical predictions based on previous data.

For their latest paper, Riess’s team studied two types of standard candles in 18 galaxies using hundreds of hours of observing time on the Hubble Space Telescope. “We’ve been going gangbusters with this,” says Riess.

Their paper, which has been submitted to a journal and posted on the arXiv online repository on 6 April, reports that they measured the constant with an uncertainty of 2.4%, down from a previous best result2 of 3.3%. They find the speed of expansion to be about 8% faster than that predicted based on Planck data, says Riess. [emphasis mine]

I highlight the number of galaxies used to get this data because I think these scientists, are being a bit over-confident about the uncertainty of their data. The universe has untold trillions of galaxies. To say they have narrowed their uncertainty down to only 2.4% based on 18 is the height of silliness.

But then, the lead scientist, Adam Riess, recognizes this, as he is also quoted in the article saying “I think that there is something in the standard cosmological model that we don’t understand.”

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The supernovae that fertilized the Earth

5:45 pm

A new study has pinned down the dates of two recent supernovae that showered the Earth with the heavier elements that make life here possible.

Many mainstream articles about this story have been implying that this research has discovered the existence of supernovae near the primordial Earth. This is false. Scientists have had evidence of these early supernovae for decades, from asteroids, in isotopes on Earth, and in the existence of the Local Bubble in which the Sun is presently traveling. What this study has done is narrow the location and the time of at least two of these supernovae, a significant discovery, though not the one much of the ignorant press is pushing.

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India signs deal for its own LIGO

11:56 am

India today signed an agreement with the National Science Foundation to build its own LIGO gravitational wave detector

This deal, combined with the possibility that TMT might move to India as well, suggests that India is about to move aggressively from the Third World to the First. And the reason, after decades of wallowing in poverty and failure, is that they finally abandoned in the late 1990s the Soviet models of socialism and communism and embraced private enterprise and capitalism, ideas championed by the United States.

If only some modern Americans would do the same.

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Earth forming around sun-like star?

9:51 am

proto-planetary disk

Worlds without end: The ground-based telescope ALMA has imaged a proto-planetary disk around a sun-like star that suggests an exoEarth is forming there the same distance from the star as our Earth is from our Sun.

The star, TW Hydrae, is a popular target of study for astronomers because of its proximity to Earth (approximately 175 light-years away) and its status as a veritable newborn (about 10 million years old). It also has a face-on orientation as seen from Earth. This affords astronomers a rare, undistorted view of the complete disk. “Previous studies with optical and radio telescopes confirm that this star hosts a prominent disk with features that strongly suggest planets are beginning to coalesce,” said Sean Andrews with the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., and lead author on a paper published today in Astrophysical Journal Letters. “The new ALMA images show the disk in unprecedented detail, revealing a series of concentric dusty bright rings and dark gaps, including intriguing features that suggest a planet with an Earth-like orbit is forming there.”

Other pronounced gap features are located 3 billion and 6 billion kilometers from the central star, similar to the distances from the Sun to Uranus and Pluto in our own Solar System.

The image above right is the inner section of that disk, showing the gap at one astronomical unit, or about 100 million miles from the star, the same as the distance of the Earth from the Sun. Essentially, this relatively close star system is providing us a perfect opportunity to study the formation of a solar system not unlike our own.

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A possible impact on Jupiter?

5:26 pm

On March 17 two different amateur astronomers have taken videos of a bright flash on Jupiter which suggests something had crashed into the gas giant.

March 17th’s impact, if the evidence for it holds up, becomes the fourth such event in the past decade. The largest of these occurred July 19, 2009, and it left a distinctly dark “powder burn” in Jupiter’s upper atmosphere first spotted by Australian astro-imager Anthony Wesley. That was followed by three lesser strikes on June 3, 2010 (recorded independently by Wesley and Christopher Go); on August 10, 2010 (independently seen by Masayuki Tachikawa and Kazuo Aoki); and on September 10, 2012 (seen visually by Dan Petersen and independently recorded by George Hall).

Counting the historic multiple-hit crash of Comet Shoemaker-Levy 9 in July 1994, that’s a grand total of six impacts on Jupiter in the past 22 years.

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Combined Earth-Space radio array discovers superhot quasar interior

11:01 am

The uncertainty of science: Data obtained by combining four ground-based radio telescopes with the Russian orbiting RadioAstron 10-meter radio telescope have detected temperatures of 10 trillion degrees in the quasar 3C 273, a hundred times hotter than predicted possible by theory.

Supermassive black holes, containing millions to billions times the mass of our Sun, reside at the centers of all massive galaxies. These black holes can drive powerful jets that emit prodigiously, often outshining all the stars in their host galaxies. But there is a limit to how bright these jets can be – when electrons get hotter than about 100 billion degrees, they interact with their own emission to produce X-rays and Gamma-rays and quickly cool down.

Astronomers have just reported a startling violation of this long-standing theoretical limit in the quasar 3C 273. “We measure the effective temperature of the quasar core to be hotter than 10 trillion degrees!” comments Yuri Kovalev (Astro Space Center, Lebedev Physical Institute, Moscow, Russia), the RadioAstron project scientist. “This result is very challenging to explain with our current understanding of how relativistic jets of quasars radiate.”

In addition, the higher resolution of the radio images produced by this space/ground-based array was good enough to see the effect produced by the structure of the interstellar material between here and the quasar.

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Video suggests Hitomi tumbling in orbit

9:17 am

Video taken by an amateur astronomer of Hitomi shows it spinning out of control, another indication that something catastrophic occurred to the newly launched X-ray telescope.

The video shows an object that looks like Hitomi, which lost contact Saturday with the Japan Aerospace Exploration Agency (JAXA), shining and then turning extremely dark in short intervals. The wild changes in brightness might mean its sunlight-reflecting side is moving turbulently. “The fact that it is rotating with extreme variations in brightness indicates that it is not controlled and that some event caused it to begin its rotation,” Paul Maley, a former NASA flight controller who observed Hitomi from the ground in Arizona, was quoted as saying.

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Debris spotted near Hitomi

8:31 am

U.S. military observations have detected debris near the Japanese X-ray telescope Hitomi that has failed to respond to communication signals.

The U.S. Joint Space Operations Center on Sunday said it has spotted five objects floating near Japan’s brand new Hitomi X-ray astronomy satellite that lost communication with Earth the previous day. In a Twitter post, the center, which tracks objects in orbit, said it identified five pieces of “break up” debris in the vicinity of the satellite.

None of this sounds encouraging.

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