Astronomers have found the largest yellow star yet, 1,300 times bigger than the Sun.
My heart bleeds: The IAU has issued a press release condemning the public’s naming of Martian craters as initiated by the private company Uwingu.
This war over the right to name features on other planets is mostly a tempest in a teapot, as the actual names will finally be decided by the people who end up living there. Nonetheless, I really like how Uwingu is pushing the IAU’s buttons, as that organization’s self-righteous insistence that it has the power to name everything in space, from craters to the smallest boulders, has for years struck me as pompous and wrong.
The Milky Way’s council of galaxies.
“All bright galaxies within 20 million light years, including us, are organized in a ‘Local Sheet’ 34-million light years across and only 1.5-million light years thick,” says McCall. “The Milky Way and Andromeda are encircled by twelve large galaxies arranged in a ring about 24-million light years across – this ‘Council of Giants’ stands in gravitational judgment of the Local Group by restricting its range of influence.”
McCall says twelve of the fourteen giants in the Local Sheet, including the Milky Way and Andromeda, are “spiral galaxies” which have highly flattened disks in which stars are forming. The remaining two are more puffy “elliptical galaxies”, whose stellar bulks were laid down long ago. Intriguingly, the two ellipticals sit on opposite sides of the Council. Winds expelled in the earliest phases of their development might have shepherded gas towards the Local Group, thereby helping to build the disks of the Milky Way and Andromeda.
WISE’s survey of the sky in infrared has now shown that there is no large planet X orbiting beyond Pluto.
This recent study, which involved an examination of WISE data covering the entire sky in infrared light, found no object the size of Saturn or larger exists out to a distance of 10,000 astronomical units (au), and no object larger than Jupiter exists out to 26,000 au. One astronomical unit equals 93 million miles. Earth is 1 au, and Pluto about 40 au, from the sun. “The outer solar system probably does not contain a large gas giant planet, or a small, companion star,” said Kevin Luhman of the Center for Exoplanets and Habitable Worlds at Penn State University, University Park, Pa., author of a paper in the Astrophysical Journal describing the results.
The theory, popular among planetary scientists and journalists, is that this theorized distant planet would periodically disturb the orbits of comets in the Oort Cloud, sending them raining down on Earth and thus cause the periodic extinction events found in the paleontological record. It was a cute theory, but based on little data. Now we have the data, and no such planet exists.
The data has found a lot of previously unknown nearby stars and brown dwarfs, which is significant in that they are close and can be studied more easily.
Chicken Little report: Another rock will fly past the Earth today, killing no one.
The 33-foot-wide (10 meters) near-Earth asteroid 2014 EC will come within 34,550 miles (55,600 kilometers) of Earth’s surface this evening (March 6) — just 14 percent of the distance between our planet and the moon, which is about 239,000 miles (385,000 km) on average.
The key quote, however, is this:
Such back-to-back flybys are pretty special, though they can’t exactly be called rare events, [JPL scientist Don] Yeomans said. “For small asteroids, one would expect a flyby of the Earth, to within the moon’s distance, about every two weeks,” he said.
In other words, these flybys happen a lot, with no consequences.
Chicken Little report: A 100-foot diameter newly discovered asteroid will zip past the Earth inside the Moon’s orbit today at 4:07 pm Eastern.
The asteroid, dubbed 2014 DX 110, is about 100 feet in diameter and is set to come within 216,000 miles of Earth — a close shave by astronomical standards, considering our Moon orbits the Earth at a distance of about 238,900 miles.
While an object that size may not seem imposing, if it were to strike the Earth, it would release a devastating amount of energy greater than a nuclear weapon. The infamous asteroid that exploded over Tunguska, Siberia, on June 30, 1908, has been estimated to be about 30 meters to 60 meters — 100 feet to 200 feet — in diameter.
While it is true that the impact would be significant, this news report does the typical fear-mongering to make the story seem interesting. The problem, however, is that the detection of these fly-bys is becoming more frequent. The number of asteroids isn’t changing, but our ability to spot them is, and with more frequent discoveries comes more frequent news stories like this. I fear that such stories — fueled by press releases from various astronomy organizations — are going to begin to sound like a kid “crying wolf” to the general public. The threat from an asteroid impact is real, even if most asteroids miss us. Desensitizing the public to the threat is not a good thing.
Amateur astronomers can help a commercial space start-up by taking pictures of its cubesat SkyCube in orbit.
The cubesate was launched from ISS last week, but has not operated as expected and they want to know why. Images would help.
Using archived Kepler data combined with statistical modeling, scientists have proposed the discovery of another 715 exoplanets.
This announcement is neat, but despite the many news stories about it today, it should be taken with a grain of salt. What the scientists have really done is pinpoint 715 stars where further research is likely to produce good exoplanet results. It is not guaranteed, however, that a scientist looking at these stars will actually see an exoplanet.
A September asteroid impact on the Moon captured as it happened by Spanish astronomers.
On 11 September 2013, Prof Jose M. Madiedo was operating two telescopes in the south of Spain that were searching for these impact events. At 2007 GMT he witnessed an unusually long and bright flash in Mare Nubium, an ancient lava-filled basin with a darker appearance than its surroundings. The flash was the result of a rock crashing into the lunar surface and was briefly almost as bright as the familiar Pole Star, meaning that anyone on Earth who was lucky enough to be looking at the Moon at that moment would have been able to see it. In the video recording made by Prof Madiedo, an afterglow remained visible for a further eight seconds. The September event is the longest and brightest confirmed impact flash ever observed on the Moon.
The uncertainty of science: A renowned astronomer reminds everyone — the public, the astronomy community, and most importantly, the press — that the data collected on most exoplanets so far are far more uncertain than is often claimed.
A planet’s atmosphere is the gateway to its identity, including how it was formed, how it developed and whether it can sustain life, stated Adam Burrows, author of the review and a Princeton University professor of astrophysical sciences. But the dominant methods for studying exoplanet atmospheres are not intended for objects as distant, dim and complex as planets trillions of miles from Earth, Burrows said. They were instead designed to study much closer or brighter objects, such as planets in Earth’s solar system and stars.
Nonetheless, scientific reports and the popular media brim with excited depictions of Earth-like planets ripe for hosting life and other conclusions that are based on vague and incomplete data, Burrows wrote in the first in a planned series of essays that examine the current and future study of exoplanets. Despite many trumpeted results, few “hard facts” about exoplanet atmospheres have been collected since the first planet was detected in 1992, and most of these data are of “marginal utility.”
The good news is that the past 20 years of study have brought a new generation of exoplanet researchers to the fore that is establishing new techniques, technologies and theories. As with any relatively new field of study, fully understanding exoplanets will require a lot of time, resources and patience, Burrows said. “Exoplanet research is in a period of productive fermentation that implies we’re doing something new that will indeed mature,” Burrows said. “Our observations just aren’t yet of a quality that is good enough to draw the conclusions we want to draw. “There’s a lot of hype in this subject, a lot of irrational exuberance. Popular media have characterized our understanding as better than it actually is,” he said. “They’ve been able to generate excitement that creates a positive connection between the astrophysics community and the public at large, but it’s important not to hype conclusions too much at this point.” [emphasis mine]
Burrows’ point is absolutely right. Every single story describing the atmosphere or make-up of any particular exoplanet at this point in time is essentially fantasy. The data are too weak or vague, and hardly robust enough to come to any solid conclusions. In fact, this research repeatedly reminds me of the conclusions many scientists drew from the flimsy spectrographic data that was gathered before the space age about the solar system’s planets. When we finally got spacecraft to those planets, we found those conclusions were routinely wrong.
This is not to say that our new knowledge of exoplanets is not exciting or significant. It is both. We just shouldn’t put too much faith in it at this time.
Europe approves its own more advanced version of Kepler to launch in 2024 and hunt for exoplanets across half the sky.
During its six year long planned mission, PLATO will observe one million stars, leading to the likely discovery and characterisation of thousands of new planets circling other stars. PLATO will scan and observe about half the sky, including the brightest and nearest stars.
PLATO consists of an array of 34 individual telescopes mounted on an observing platform in the space probe. The satellite will be positioned at one of the so-called Lagrangian Points , where the gravitational pull of the Sun and the Earth cancel each other out so the satellite will stay at a fixed position in space. Each of the 34 telescopes has an aperture of 12 centimeters. The individual telescopes can be combined in many different modes and bundled together, leading to unprecedented capabilities to simultaneously observe both bright and dim objects. PLATO will be equipped with the largest camera-system sensor ever flown in space, comprising 136 charge-coupled devices (CCDs) that have a combined area of 0.9 square metres.
What I like about this is that this project is essentially putting another optical telescope in space. The more of these we have the more discoveries we will make, as even a tiny optical telescope in the vacuum of space is more productive than a giant ground-based telescope looking through the foggy atmosphere of Earth.
The uncertainty of science: Cosmologists, using new data, are now reconsidering their theories on the manner in which the universe began organizing itself after the Big Bang.
Scientists call it the epoch of reionization, the period in which a newborn universe went from darkness to light as the first stars, galaxies and black holes began forming and radiating energy.
In a paper published Thursday in Nature, researchers are challenging one long-held conception about how quickly the universe began warming during this transition period. Based on observations of X-ray emissions from binary star systems, as well as new mathematical models, cosmologists at Tel Aviv University and Harvard say that heating of the universe progressed much more slowly, and uniformly, than previously thought.
Curiosity takes its first image of the Earth/Moon system from Mars.
Jupiter’s shrinking Great Red Spot.
In the 1880s the GRS resembled a huge blimp gliding high above white crystalline clouds of ammonia and spanned 40,000 km (25, 000 miles) across. You couldn’t miss it even in those small brass refractors that were the standard amateur observing gear back in the day. Nearly one hundred years later in 1979, the Spot’s north-south extent has remained virtually unchanged, but it’s girth had shrunk to 25,000 km (15,535 miles) or just shy of two Earth diameters. Recent work done by expert astrophotographer Damian Peach using the WINJUPOS program to precisely measure the GRS in high resolution photos over the past 10 years indicates a continued steady shrinkage.
Lots more fascinating information at the link. Read it all.
The reactivation of Rosetta continues, with no serious issues so far.
The National Science Foundation wants to get rid of some of its older big telescopes, and you can buy them!
We are not talking small here. The biggest is the Green Bank Radio Telescope in West Virginia, which though only fourteen years old is unable to compete scientificially with the new large radio telescope arrays. In truth, when it was mostly built to satisfy the pork ambitions of the late Democratic Senator Robert Byrd.
After dimming for decades, the North Star is now getting brighter.
My very first published article, once I changed careers to become a freelance science writer, was a story in 1995 about the mysterious changes that astronomers had noticed Polaris undergoing. It appears those mysterious changes continue.
Come October 2014 astronomers will attempt to weigh Proxima Centauri, the nearest star.
For more information about that newly discovered supernova in the nearby galaxy M82 go here and here.
The first link notes that the supernova has brightened to 11.5 magnitude and could get even brighter in the next two weeks. Though still too dim for the naked eye, it is easily bright enough right now for most amateur telescopes and binoculars. How much brighter it will get remains a question.
Using the Herschel Space Telescope astronomers have detected water vapor spurting from Ceres, the solar system’s largest asteroid.
Herschel’s sensors spied plumes during three of the four observation periods. The strength of absorption varied over a matter of hours, a trend probably caused by relatively small sources of water vapour rotating in and out of view of Earth, the researchers say.
Data gathered in March 2013 suggest that the plumes originated from two widely separated, 60-kilometre-wide spots in the dwarf planet’s mid-latitude regions. Together, these spots ejected about 6 kilograms of water vapour into space each second. Neither ground-based observations nor images from the Hubble Space Telescope are keen enough to identify the as-yet-mysterious areas, says Küppers. “We don’t know what these features are, we just know that they’re darker than their surroundings,” he notes.
The NASA probe Dawn will arrive at Ceres early next year, and take a good look at these plumes. Should be exciting.
A new supernova, bright enough to be visible to amateurs, was discovered last night in the nearby galaxy M82.
Astronomers have discovered the first exoplanet orbiting a star almost identical to the Sun.
Astronomers have used ESO’s HARPS planet hunter in Chile, along with other telescopes around the world, to discover three planets orbiting stars in the cluster Messier 67. Although more than one thousand planets outside the Solar System are now confirmed, only a handful have been found in star clusters. Remarkably one of these new exoplanets is orbiting a star that is a rare solar twin — a star that is almost identical to the Sun in all respects.
This discovery is interesting in that some astronomers have proposed that our Sun itself was born in M67, the open galactic star cluster where these exoplanets were found. My March 2012 cover story for Sky & Telescope was on this very subject.
Astronomers have identified a star they expect to go supernova very soon.
[SBW2007] 1 (or SBW1) is located 20,000 light-years from Earth and features an enigmatic double-ringed planetary nebula. The rings are gases that have been blasted from the outermost layers of the blue supergiant star in the nebula’s core. The star, which was estimated to be 20 times the mass of the sun before it became unstable, is going through its final death throes before a supernova is initiated. But don’t worry, the supernova would be a safe distance from us, although it will put on an exciting light show.
There is no way to predict when the supernova will occur. On the timescales of stellar evolution, it could happen tomorrow, or in a thousand years. For the full Hubble image go here.
This story is significant in that it shows how much knowledge has been gained in astronomy since Hubble’s launch. In 1987, when Supernova 1987a exploded in the Large Magellanic Cloud, astronomers had not identified even one progenitor of any supernova, and did not have any clear idea what kinds of stars produced these gigantic explosions. Today, they have identified more than a handful, and are even beginning to pinpoint candidates, such as the star above, that could be the next stars to go boom.
Astronomers announced today the discovery of 18 sunlike stars which are traveling so fast they will escape the Milky Way galaxy.
These sunlike stars are in addition to another 20 blue giant stars that are also traveling at escape velocity.
The origin of all of these new stars is completely mysterious. The theory had been that such stars got their speed boost by being flung past the galaxy’s central supermassive black hole, dubbed Sagittarius A* (pronounced “A-star”). These new stars, however, come from other directions, and in fact appear to have even come from outside the galaxy’s main disk. Thus, astronomers are baffled as to what caused them to be traveling so fast.
A direct image of an exoplanet.
What’s most amazing is this image was taken by a ground-based telescope.
The recently reactivated WISE space telescope has discovered its first new asteroid.
2013 YP139 is about 27 million miles (43 million kilometers) from Earth. Based on its infrared brightness, scientists estimate it to be roughly 0.4 miles (650 meters) in diameter and extremely dark, like a piece of coal. The asteroid circles the sun in an elliptical orbit tilted to the plane of our solar system and is classified as potentially hazardous. It is possible for its orbit to bring it as close as 300,000 miles from Earth, a little more than the distance to the moon. However, it will not come that close within the next century.
WISE, renamed NEOWISE by NASA, is expected to come up with a lot more of these in the coming years.
Worlds without end: Astronomers, using Kepler data, have identified dozens of exoplanets between 1 and 4 times the mass of the Earth.
One of those planets has the same mass as the Earth, but is far less dense.
The significant fact however that came out of the press conference announcing these results is the belief by astronomers that, based on this data, they expect that 1 in 5 solar systems will have an Earth-sized planet.
Scientists think they have found cloudy skies on two nearby exoplanets.
One planet is a super Earth, while the other is Neptune-sized.
This finding, as fascinating as it is, is also incredibly uncertain. The data suggests clouds, but the data is quite thin. We are barely seeing what’s there. Without doubt, the reality is far more complex — and interesting — than presently theorized.
