All posts by Daniel

New Picture Of “Rotten Egg” Nebula Highlights Last Hurrah Of A Dying Star

The Hubble space telescope has captured a brilliant picture of OH 231.8+04.2, also known as the Calabash Nebula because of its similar shape to the southern African gourd.

The highly detailed image shows the consequences of an old star losing its outer layers, transforming from a red giant star into a planetary nebula. The ejected material is being propelled at theincredible speed of 1 million kilometers (620,000 miles) per hour.

The Calabash nebula is located 5,000 light-years away in the constellation of Puppis, in the southern hemisphere. It is also known as the Rotten Egg nebula because scientists discovered that the nebula is rich in sulphur, which is one of the elements responsible for the characteristic smell of a rotten egg. But don’t worry, the density of Earth’s atmosphere is a thousand trillion times the density of a planetary nebula, so even if you were there, you wouldnt be smelling much.

This shot is an incredible view of a fleeting phenomenon, in astronomical timescales. Planetary nebulae form in just a few thousand years, which is a blink compared to stars’ lifetimes of several billions of years.

It is also a window into the future of the Sun and the many low-mass stars that inhabit the universe. Only stars that are heavier than eight of our Suns can become supernovae. The others evolve into red giants and then turn into planetary nebulae.

These red giants have a dense, incredibly hot core (temperatures of many millions of degrees) and they swell up, with the outer layer loosely bound by gravity. The energetic photons from the core push the gas away and excite it, turning the lost layers into a brightly shining nebula.

Eventually, the star loses its cover and cools down. The star becomes a white dwarf and the outer layers, without the hot photons, stop shining.

The name planetary nebula is a misnomer. They are not related to planets at all. But the first astronomer to see one, William Hershel, thought they looked a bit like a planet, being somewhat round, and for better or for worse the name stuck.

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Astronomers Find Smallest Galaxy With Supermassive Black Hole

Astronomers have recently discovered that a little galaxy has a big secret. Ultra compact dwarf galaxies (UCD) contain about 100 million stars spanning a couple hundred light years. As a comparison, our Milky Way has about 300 billion stars spread across 100,000 light years. Using the Hubble Space Telescope, an international team of astronomers led by Anil Seth of the University of Utah discovered that M60-UCD1 has a supermassive black hole, making it the smallest galaxy ever discovered to have one. The paper was published in Nature.

M60-UCD1 is located about 54 million light years away and is a satellite of the larger elliptical galaxy Messier 60 in the constellation Virgo. The tiny galaxy is only 300 light years across, but the team discovered in September 2013 that it is likely the densest known galaxy. This follow-up study has revealed that a supermassive black hole at the center might be the cause for that.

“We’ve known for some time that many UCDs are a bit overweight. They just appear to be too heavy for the luminosity of their stars,” co-author Steffen Mieske said in a press release. “We had already published a study that suggested this additional weight could come from the presence of supermassive black holes, but it was only a theory. Now, by studying the movement of the stars within M60-UCD1, we have detected the effects of such a black hole at its centre. This is a very exciting result and we want to know how many more UCDs may harbor such extremely massive objects.”

Supermassive black holes are the largest known type of black hole, which are over hundreds of thousands of times more massive than our Sun. The supermassive black hole at the center of M60-UCD1 is roughly equal to 20 million solar masses and makes up a whopping 15% of the galaxy’s total mass

“That is pretty amazing, given that the Milky Way is 500 times larger and more than 1000 times heavier than M60-UCD1,” Seth explained. “In fact, even though the black hole at the center of our Milky Way galaxy has the mass of 4 million Suns it is still less than 0.01 percent of the Milky Way’s total mass, which makes you realize how significant M60-UCD1’s black hole really is.”

As the black hole and galaxy have such extreme proportions, it became a wonder how they were ever able to form. The team suspects that the galaxy actually used to be much larger, balancing the mass ratios out a bit more. In the past, the galaxy might have been home to as many as 10 billion stars. When crossing near Messier 60, tidal forces from the larger galaxy might have stripped away the vast majority of M60-UCD1’s outer stars.

“This finding suggests that dwarf galaxies may actually be the stripped remnants of larger galaxies that were torn apart during collisions with other galaxies, rather than small islands of stars born in isolation,” Seth concluded. “We don’t know of any other way you could make a black hole so big in an object this small.”

If this is true for M60-UCD1, it could be possible that more dwarf galaxies also have massive black holes at the center as well. This could potentially double the amount of known black holes in the Universe.

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Weather Detected On A World With Sapphire And Ruby Clouds

Changing weather has been detected on a world where clouds are probably made of corundum, the primary material of rubies and sapphires. Although there have been reports of weather observations for distant planets before, seeing changes with time represents something new.

HAT-P-7 b would not be a fun place to visit even if you could travel the 1,044 light-years to get there. Average surface temperatures are 1,900C (3,500F), making Venus look positively chilly. Nevertheless, a paper in Nature Astronomy reveals local changes in weather with time, a first for a planet orbiting another star.

With a radius 1.4 times that of Jupiter and an orbital period of just 2.2 days, HAT-P-7 b is an archetypal hot Jupiter, a superheated gas giant. Like most such planets it is tidally locked; one side permanently faces the star, the other experiences eternal night. Based on its light’s peak wavelength, temperatures on the day side are 390C (730F) above the planetary average.

Using four years of Kepler space telescope observations, a team led by Dr David Armstrong of the University of Warwick found large variations around these extreme values, demonstrating that weather conditions are not constant there.

We cannot be certain what is causing this variability, but HAT-P-7 b’s thick atmosphere should be carrying plenty of energy from the day side to where it is night. The paper notes that if there is variation in the efficiency of this process energy would build up at times on the day side, before being released, and get results like those that have been observed.

Conditions are too hot on HAT-P-7 b for clouds as we know them on Earth, but the authors point out that there may well be aerosols of corundum (a form of aluminum oxide that becomes precious stones when impurities give it color) and perovskite in the night-side atmosphere. If these get blown into the morning zone, and persist there for a while, it would affecthow much light HAT-P-7 b reflects, and thus the temperature. The build-up and dispersal of these aerosols, caused by inconsistent wind speeds, could drive the temperature variations we see.

Previous reports of weather maps for exoplanets might more accurately have been considered climate maps, for example revealing how average temperatures vary on the day and night sides differ on tidally locked planets.

We’ve also seen weather changes on a planet-sized object traveling unaccompanied through space, but overcoming the challenges of detecting these sorts of changes hidden in the powerful glow of a star is something new. Armstrong’s work represents a step towards the much more difficult goal of seeing something similar on an Earth-like world, including one that might support life.

A comparison of HAT-P-7’s brightness as seen from ground-based telescopes and Kepler. The dip represents when HAT-P-7 b passes in front of its star. The advantages of space observations are clear.NASA Ames Research Center

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Cat Fights Off Alligator Over Chicken Meat

A bunch of tourist enjoying themselves on the Cajun Pride Swamp Tours in LaPlace, Louisiana happened upon a battle of the centuries. An alligator and an ordinary house-cat had a face off over a very yummy chicken dinner. One might be surprised by the ending. The video from 2010 just had a viral surge, and is featured on DailyMailBlameItOnTheVoices, NBCSportsArbroath, and TastefullyOffensive


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Packing for Interstellar Space Voyage: What to Bring?


Contemplating the idea of a manned voyage to another star raises many confounding questions, including one that has been around since the days of the first travelers: What to pack?

To build a closed environment that can sustain astronauts and perhaps their descendants during the long mission is going to require many kinds of technological innovations, some of them needed just to clothe the interstellar travelers, said Karl Aspelund, a professor of textiles, fashion merchandising and design at the University of Rhode Island.

“The longest time anyone has been in space is around 400 days. Now we’re suddenly talking years, decades, possibly even generations,” Aspelund said last week at the 100 Year Starship Symposium in Houston, a conference about interstellar space travel. “That changes everything.”

An interstellar mission is most likely going to be a very extended trip, considering the nearest stars are light-years away. Aspelund estimated that every person aboard a ship on a 30-year voyage would need to pack about 100 cubic feet of clothing. For 10 people, that means enough clothes to fill a railcar. Based on current launch costs, so much mass could add $18 million to $36 million to the price tag for the mission simply for shirts, pants and underwear, he calculated.

Clearly, future astronauts will have to pack lighter.

“We might have to rethink the idea of clothing altogether,” Aspelund said. “We might have to really re-evaluate what constitutes being dressed and undressed.”

Aspelund is only half joking when he contemplates sending spaceflyers onto a starship naked. He concedes there are good reasons ? culturally as well as individually ? why humans couldn’t just discard clothes on an interstellar mission.

But researchers will need to find ways for clothes (and everything else astronauts pack) to be used sustainably, he says.

So far NASA hasn’t figured out many good ways to do laundry in space. Astronauts on the International Space Station have been known to rarely change outfits.

“It’s basically a flying dorm room, by the sound of it,” Aspelund said of the space station. “The solution to keeping things clean is exactly the dorm room solution: You stuff it into a hole and you never see it again. That’s not so good if you’re not going to be coming back, or if you’re going to be out there for years.”

Aspelund plans to write a grant and collaborate with other researchers on the issue of cosmic duds and space laundry. The solutions may require completely different types of textiles that are more durable and recyclable, or new ways to clean existing materials.

On an even deeper level, the issue forces people to question just what items are essential for life on Earth and whether those same items are essential in space.

“We have things that are absolutely critical to our well-being on the planet,” Aspelund said. “This project, the 100 Year Starship, inspires a completely fresh look. Suddenly we step back from Earthly concerns.”

This article originally published at

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First Ever Map Of The Magnetic Field Across The Magellanic Clouds

The Small and Large Magellanic, two of the Milky Ways closest neighbors, are linked together by a bridge of neutral hydrogen and now, for the first time, astronomers have been able to map the magnetic field streaming through it.

An international team of researchers has used an Australian radio telescope to study the 75,000-light-year gas bridge and measured a magnetic field about a million times weaker than Earths own. Their results are published in the Monthly Notices of the Royal Astronomical Society.

The Small and Large Magellanic Clouds (SMC and LMC) are two dwarf galaxies orbiting our galaxy at a distance of 200,000 and 160,000 light-years respectively. Now that the researchers have proved that the magnetic field exists, they hope to understand if it is generated by the galaxies or by the Magellanic Bridge itself.

There were hints that this magnetic field might exist, but no one had observed it until now, lead author Jane Kaczmarek, from the University of Sydney, said in a statement.

Understanding the role that magnetic fields play in the evolution of galaxies and their environment is a fundamental question in astronomy that remains to be answered.

The researchers suggest that as the two galaxies interacted with each other their magnetic fields have been pulled together by the gas that formed the bridge (and a few stars), with a single intergalactic magnetic field across both galaxies.

In general, we dont know how such vast magnetic fields are generated, nor how these large-scale magnetic fields affect galaxy formation and evolution, added Kaczmarek. The LMC and SMC are our nearest neighbors, so understanding how they evolve may help us understand how our Milky Way Galaxy will evolve.

Detecting such a weak and distant magnetic field has not been easy. The researchers use the polarization of light to work out the effect of magnetic fields. Polarized light waves oscillate in a single direction, and when they pass through a magnetic field the plane in which they are polarized is rotated. So the team used the Australia Telescope Compact Array radio telescope to study the light from 167 polarized extragalactic radio sources.

The radio emission from the distant galaxies served as background flashlights that shine through the Bridge, says Kaczmarek. Its magnetic field then changes the polarization of the radio signal. How the polarized light is changed tells us about the intervening magnetic field.

More and more galaxies and galactic structures appear to have extended magnetic fields. Astronomers have begun to study them and soon we might see how much of a role they play in the cosmic arena.

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Papyrus Reveals Ancient Egyptian Astronomical Knowledge

Researchers from the University of Helsinki have proposed that ancient Egyptians 3,000 years ago were the first to record the variability of a distant star and their records could provide useful information for astronomers today.

A new paper published in PLOS ONE explains how the Egyptian Cairo Calendar from 1244 to 1163 B.C. describes the variability of a binary star system called Algol. In the calendar, there are two significant periods of time for two gods 29.6 and 2.85 days. The former relates to the period of the Moon, while the latter almost perfectly matches the variability of Algol which today is 2.867 days, or two days, 20 hours, and 49 minutes.

This theory had been proposed in 2013 but, understandably, had been met with some skepticism. However, the researchers now say they are more confident in their claims, and say that Algol relates to the deity Horus.

I would have serious doubts, if someone claimed, for example, that the Bible contains information about water in Mars, said lead author Lauri Jetsu in a statement. We claimed that Ancient Egyptian religious texts contain astrophysical information about Algol. It was no surprise to us that there were, and there still are, sceptics.

Shown is an extract of the Cairo Calendar papyrus, used courtesy of Lauri Jetsu

An eclipsing binary is a pair of stars that, as viewed from Earth, rotate around each other and block each other’s light. Thus, this particular star dims regularly in brightness as it orbits its companion. Algol is found in the constellation Perseus about 92.8 light-years from us; the larger star is about 3.5 times the radius of the Sun, and the smaller about 2.7. They are separated by about 0.062 astronomical units (AU, one AU is the Earth-Sun distance).

The variability of Algol, which can be seen with the naked eye, was thought to have been first recorded by Italian astronomer Geminiano Montanari in 1667, although it was not until 1783 that British astronomer John Goodricke suggested another object may be the cause of the dimming. Based on this latest assumption, however, the record for discovery of this star’s variability may have to be re-awarded.

Perhaps most interestingly, the discovery reveals that the variability of the star has decreased very slightly over three millennia, by about 0.017 days. Rather than being an error, the researchers postulate that this could be due to the transfer of mass between the two stars affecting their orbits.

In fact, this would be the first observation that confirms the period increase of Algol and it also gives an estimate of the mass transfer rate, added Jetsu, possibly providing an important tool for astronomers today to learn more about eclipsing binaries.

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Comet, Earth and Mercury Seen Together in Rare Video

A new video from a NASA spacecraft studying the sun has captured an unexpected sight: a wandering comet posing with the planets Earth and Mercury.

The cosmic view comes from one of NASA’s twin Stereo spacecraft that constantly watch the sun for signs of solar flares and other space weather events. It shows Mercury and Earth as they appeared with the Comet Pan-STARRS, a comet that is currently visible from the Northern Hemisphere during evening twilight.

The probe captured the video of Comet Pan-STARRS, Earth and Mercury together while observing the sun from March 9 to March 12.

According to a NASA description, the video “shows the comet and its fluttering tail as it moves through space.” The Earth appears as a bright stationary object on the right side of the video, while Mercury is visible as a moving light on the left side.

The sun is actually out of the frame in the Stereo-B spacecraft’s video, but its solar wind is visible as a stream of material, NASA officials explained. Meanwhile, the view of Comet Pan-STARRS from space is giving scientists a wealth of data to review, they added.

“Comet scientists say the tail looks quite complex and it will take computer models to help understand exactly what’s happening in STEREO’s observations,” agency officials said in a video description. “The comet should remain visible to the naked eye through the end of March.”

Comet Pan-STARRS is currently visible to stargazers in the Northern Hemisphere just after sunset. To see the comet, look low on the western horizon just after the sun has gone down. Comet Pan-STARRS can appear as a bright head with a wispy trail, weather permitting, though some stargazers have said the bright evening twilight can make spotting it tricky.

The Comet Pan-STARRS was discovered in June 2011 by astronomers using the Panoramic Survey Telescope & Rapid Response System (Pan-STARRS) in Hawaii. The comet’s official name is C/2011 L4 (PANSTARRS).

Scientists estimate that Comet Pan-STARRS takes more than 100 million years to orbit the sun once. The comet crossed into the Northern Hemisphere evening sky last week after months of being visible to observers in the Southern Hemisphere.

NASA’s twin Stereo A and B spacecraft (the name is short for Solar TErrestrial RElations Observatory) observe the sun in tandem to provide unparalleled views of how material from solar eruptions makes its way to Earth. The spacecraft launched in 2006 and are part of a fleet of sun-watching spacecraft that monitor solar storms.

Comet Pan-STARRS is one of several comets gracing the night sky in 2013. Pan-STARRS was joined by the Comet Lemmon earlier this year when both were visible together in the Southern Hemisphere sky. Later this year, the sungrazing Comet ISON could put on a potentially dazzling display when it makes its closest approach to the sun in late November.

Homepage image courtesy of Astronomy Education Services/Gingin Observatory

This article originally published at

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