Watching how exoplanet news hits the press is always interesting, but I was surprised at how the discovery of CoRoT-9b (discussed here yesterday) was received. The scientific reward could be significant, which is why one scientist referred to the find as a 'Rosetta stone,' but the fact that we had a gas giant that was both analyzable through transits and not a 'hot Jupiter' evidently needed to be ginned up in some media circles. What emerged were headlines seeing similarities to our Solar System (New Exoplanet Like One of Ours) and making bizarre extrapolations: Corot-9b: Extra Solar Planet Proffers Hope of Inhabitation. I suppose CoRoT-9b is like a planet in our Solar System in being a gas giant in a stable orbit not hugging its star, but it's hardly alone in that regard. What makes it special is that we can study it both by radial velocity and transit methods, gaining insights into the composition of such 'temperate' gas giants. I suspect the headlines left many readers...

When you're studying galaxy clusters, it doesn't pay to be in a hurry. Harald Ebeling (University of Hawaii) is an expert on the matter, working with a catalog of over a thousand such clusters in a new study of the so-called 'dark flow,' the apparent motion of galaxy clusters along a path centered on the southern constellations Centaurus and Hydra. Says Ebeling: "It takes, on average, about an hour of telescope time to measure the distance to each cluster we work with, not to mention the years required to find these systems in the first place. This is a project requiring considerable followthrough." The study, led by Alexander Kashlinsky (NASA GSFC), relies on hot X-ray emitting gas within a cluster, which scatters photons from the cosmic microwave background. The wavelength of scattered photons then tells us something about the motion of individual clusters. This tiniest of shifts in the CMB's background temperature in the cluster's direction, known as the Sunyaev-Zel'dovich effect,...

Data from the Keck telescope (Mauna Kea), the Hubble Space Telescope and the Very Large Array have been used in conjunction with the findings of the Wilkinson Microwave Anisotropy Probe to offer up a new way to measure the size of the universe, as well as how rapidly it is expanding and how old it is now. By determining a value for the Hubble constant, the work confirms the age of the universe within a span of 170 million years as 13.75 billion years old. I'm always fascinated with work involving gravitational lensing -- just yesterday we looked at using the Sun's lensing effects for potential SETI investigations -- and here we have a classic case of measuring how light traveled from a bright, active galaxy along different paths to reach the Earth. A strong gravitational lens like the one used in this study, called B1608+656, creates multiple images of the same galaxy lying behind the lensing object. Studying the time the light took along each path, it was possible to gather...

We're keeping a close eye on the WISE mission (Wide-field Infrared Survey Explorer) and the possibility of identifying brown dwarfs closer to our Sun than the Centauri stars. But WISE's targets are numerous, and the early imagery coming back from the mission is promising indeed. To check out the capabilities of this space-based observatory, have a look at some of the new photos, which show M31, the Andromeda galaxy, at a variety of wavelengths. The first image was made with all four of WISE's infrared detectors -- the caption describes the color coding. Image: The immense Andromeda galaxy, also known as Messier 31 or simply M31, is captured in full in this new image from NASA's Wide-field Infrared Survey Explorer, or WISE. The mosaic covers an area equivalent to more than 100 full moons, or five degrees across the sky. WISE used all four of its infrared detectors to capture this picture (3.4- and 4.6-micron light is colored blue; 12-micron light is green; and 22-micron light is red)....

We know that new stars form out of cold gas and dust that are present in galaxies, but what accounts for the fact that star formation is slower than in earlier eras? Three to five billion years after the Big Bang, galaxies turned out stars at a much faster clip than they do today. The Milky Way seems to produce stars at a rate equaling about ten times the mass of our Sun each year, whereas similar galaxies earlier in their lives featured star formation rates that were up to ten times higher. Michael Cooper (University of Arizona) and colleagues have gone to work on this question by studying data from the DEEP2 survey of 50,000 galaxies, picking a sample of one dozen massive galaxies to represent the average population. Working with the Hubble and Spitzer space telescopes as well as radio telescope arrays in France and California, the team then observed the selected galaxies in the infrared and measured their radio frequency emissions, making cold gas clouds visible. Cooper and...

To measure the brightness of a star, astronomers compare it to standard reference stars. You would think measurements of the latter would be highly refined by now, but as this New Scientist story points out, the bright star Vega's most accurate measurements date back to the 1970s. That puts the focus on a new space telescope, or maybe New Scientist's term 'rocket-borne' is better here, because the ACCESS experiment will actually not go into orbit, but will make four suborbital flights to make measurements lasting only minutes. ACCESS (Absolute Color Calibration Experiment for Standard Stars) will look at four common reference stars: Sirius, Vega, and two much fainter objects, HD 37725 and BD+17?4708, with observing time limited to about 400 seconds. That's not much time, but it's enough for ACCESS to gauge the brightness of the four reference stars to a precision of one percent and perhaps better, twice the precision of today's measurements. Image: Standard Candles are used to...

We push deeper into the mysteries of brown dwarfs with the discovery of SDSS 1416+13B, an object orbiting another brown dwarf between fifteen and fifty light years from the Sun. The new dwarf, discovered in data collected by the United Kingdom Infrared Telescope (UKIRT) in Hawaii, is visible only in infrared light. Philip Lucas (University of Hertfordshire) cautions that there remains much we don't know about the telescope's latest find: "This looks like being the fourth time in three years that the UKIRT has made a record breaking discovery of the coolest known brown dwarf, with an estimated temperature not far above 200 degrees Celsius. We have to be a bit careful about this one because its colors are so different than anything seen before that we don't really understand it yet. Even if it turns out that the low temperature is not quite record breaking, the colors are so extreme that this object will keep a lot of physicists busy trying to explain it." Image: UKIRT UKIDSS...

Launch of the WISE mission has again been delayed, now scheduled for December 14 with a launch window of 1409 to 1423 UTC (0909-0923 EST). Launch will take place at Vandenberg Air Force Base in California, with coverage offered on NASA TV. A live feed from the on-board camera will be active here. The Wide-field Infrared Explorer will spend nine months covering the entire sky at mid-infrared wavelengths, studying targets ranging from the remotest galaxies to near-Earth objects, and building our catalog of brown dwarfs near the Sun. Most infrared wavelengths can't penetrate Earth's atmosphere, so a space-based perch -- WISE will take up a circular polar orbit some 525 kilometers up -- is essential for good viewing. The complete WISE survey will involve over a million images, forming a source catalog for the James Webb Space Telescope, which is scheduled for a 2014 launch. Image: The Wide-field Infrared Survey Explorer mission will survey the entire sky in a portion of the...

That ignorance can cause cascading errors is a lesson never better taught than through the experience of George Brown, British foreign secretary in Harold Wilson's government (this was about forty years ago). One day Brown was in Peru for a reception and, indulging in the local spirits, became thoroughly ripped. Enjoying the music, he was quick to act when a guest in flowing purple robes went by. An entranced Brown followed and asked the mysterious person to dance. The New York Times recalls the result: The purple-robed figure refused the overture. "First, you are drunk," the guest is said to have replied. "Second, this is not a waltz; it is the Peruvian national anthem. And third, I am not a woman; I am the Cardinal Archbishop of Lima." Cascading errors are always fun except when they happen to you. This morning I've had several computer glitches of increasing intensity. Finally, when I thought I had them all worked out, a window popped up advising me that my C: drive was about to...

The image at the right shows HD200775, a close binary that contains one star ten times the mass of the Sun. The two stars illuminate the surrounding cavity of molecular gas, the closest of which forms the reflection nebula known as NGC7023. The binary is located some 1400 light years from Earth and is the subject of recent work by an international team that has produced the first well-resolved images of a circumstellar disk around a young, massive star. You can see the disk they found in the mid-infrared in the second image below. Image: HD200775 and its nebula. The bright star at the center is HD200775, which illuminates the surrounding nebula. The upper and lower part of HD200775 is the reflection nebula NGC7023. The hourglass-shaped nebula extending in the east-west direction (east is left) encircles a cavity formed by past outflow activity. Okamoto et al. zoomed in and imaged an area around HD200775. Credit: DSS/2MASS/Subaru Telescope. What we're after is a better understanding...

Now that we are looking forward to the WISE mission (Wide-Field Infrared Survey Explorer) and its investigations into nearby brown dwarfs, it's startling to realize that we detected the first of these objects as recently as 1995. Today they're all the rage, particularly among that small band of us obsessed with missions to nearby interstellar space. A cool, dim brown dwarf could be the closest star to our Sun, an obvious target for a future probe once long-haul propulsion options begin to mature. Brown dwarfs are too cool to trigger hydrogen fusion, so it takes infrared capabilities like those of WISE or the Spitzer Space Telescope to tell us much about these dim objects. A key question has been whether they form like planets or stars. Spitzer may have found the answer in the form of two 'proto brown dwarfs' that have been located in a cloud called Barnard 213, a region of the Taurus-Auriga complex where young objects abound. The finding is significant because we've never before...

The Earth receives thousands of tons of interplanetary dust every year as it makes its way around the Sun. Can we trace any of this material to a particular source? Scientists from the Carnegie Institution think the answer is yes, at least in the case of comet Grigg-Skjellerup. The Carnegie team worked with interplanetary dust particles (IDPs) collected by a NASA aircraft in 2003, just after the Earth had passed through the comet's tail, focusing on the chemical, isotopic and micro-structural composition of the grains. Collecting Comet Dust A bit of background: NASA's Scott Messenger (JSC-Houston) predicted that Grigg-Skjellerup dust grains could be captured in the stratosphere at a specific time of the year (the comet reappears every five years). The dust collection flights that followed his prediction involved an ER-2 high-altitude aircraft flown out of Dryden Flight Research Center in 2003. Out of this work came the new mineral now called Brownleeite, a manganese silicide found in...

Sometimes we're reminded in a stunning way of how much material exists in the star-forming regions of the galaxy. Take a look at the image below, which comes from the Herschel Space Observatory. Herschel's SPIRE camera, which works at wavelengths between 250 and 500 microns, is combined here with data from the observatory's other camera, called PACS, which operates between 70 and 170 microns. The combination reveals detailed images in the far infrared, locating star-forming regions that would otherwise be difficult to detect at a single wavelength. Image: Five-color composite image of a 2 x 2 degree area in the plane of our Galaxy, combining the PACS and SPIRE observations. In this image the SPIRE and PACS images have been combined into a single composite; here the blue denotes 70 microns, the green 160 microns, and the red is the combination of the emission from all three SPIRE bands at 250/350/500 microns. Credit: ESA. The infrared range these instruments cover should tell us much...

I try to run interesting astronomical art wherever I can find it, but the image that accompanies this ESA news release on the discovery of an interesting white dwarf just doesn't cut it. So use your imagination as I describe the results of a study using data from ESA's XMM-Newton X-ray telescope, which have given us something we've long lacked -- highly accurate mass information for an accreting white dwarf in a binary system, one that is growing close to the point of becoming a supernova. Something in the vicinity of HD 49798 has been known to be giving off X-rays since 1997, but it has taken XMM-Newton to nail the culprit. The white dwarf near the larger star is twice as massive as expected, cramming about 1.3 solar masses into an object with a diameter about half that of our planet. Rotating every thirteen seconds, this object boasts the fastest white dwarf rotation known. Why the larger mass? We're looking at a white dwarf that is pulling gaseous material out of its companion...

Here's a surprise -- a galaxy as large as the Milky Way that houses a supermassive black hole with the equivalent of a billion suns worth of matter. The surprise isn't the object itself but its distance, some 12.8 billion light years (redshift 6.43). [See Adam Crowl's comment below: This is not actually a 'distance' but the light travel time]. That makes this a young object, assuming a universe that began roughly 13.7 billion years ago, and has implications for how such galaxies form. Tomotsugu Goto (University of Hawaii), who led the team making the discovery, notes the unusual nature of his find: "It is surprising that such a giant galaxy existed when the Universe was only one-sixteenth of its present age, and that it hosted a black hole one billion times more massive than the Sun. The galaxy and black hole must have formed very rapidly in the early universe." It seems odd to say it, but what complicates studying such distant objects is that host galaxies are often lost in the...

I don't spend too much time worrying about the ultimate fate of the Earth as it interacts with a swollen red Sun some five billion years from now. My thought is that if any civilization is still on the planet in a billion years, it will have long since worked out how to exit when necessary (and it will be necessary a lot sooner than five billion years!), or maybe how to tweak planetary orbits to preserve our planet, if only as a choice historical site. Still less do I worry about the Milky Way being destroyed by a collision with one or more satellite galaxies, like the Large and Small Magellanic Clouds that move around the parent galaxy. So when I read that an Ohio State team led by Stelios Kazantzidis had shown via computer simulations that such a collision would leave the galaxy more or less intact, my real interest was in the implications of this work in terms of one of science's great mysteries -- the nature of dark matter. Have a look at the team's modeling of the dark matter...

Back in April a paper appeared in the Astrophysical Journal that drew into question our view of star populations. We've assumed since the 1950s that we could count the stars in a particular area of sky by looking at the light from the brightest and most massive stars. In making this assumption, we were tapping the initial mass function, a way of describing the mass distribution of a group of stars in terms of their initial mass. We could, then, estimate the total number of stars based on a sample of the stars that were the easiest to see, assuming that a set number of smaller stars ought to have been created in the same region. Every star twenty or more times as massive as the Sun should be accompanied, in this thinking, by about 500 stars of solar mass or less. But Gerhardt R. Meurer (Johns Hopkins University) and team used data from the Galaxy Evolution Explorer to challenge these proportions. The numbers, it turns out, don't work out as consistently as we had thought. Says Meurer:...

Look back far enough in time (and hence far enough in distance) and you see things that don't correspond to nearby cosmic objects. The so-called 'Lyman-alpha blobs' that astronomers have found associated with young, distant galaxies are a case in point. Huge collections of hydrogen gas (some of them the largest single objects yet found in the universe), they're bright at optical wavelengths, raising the question of what powers the glow and how they factored into the galaxy formation process. New research may be offering an answer. The key is something called 'feedback,' a stage in galaxy formation that shows the interplay between galaxies and the intergalactic medium. Here, the cooling of gas within the dark matter halos enshrouding a young galaxy is countered by heating from active galactic nuclei (think supermassive black holes), which helps to enrich intergalactic space and also slow down star formation. Image: An artist's representation showing what one of the galaxies inside a...

We get yet another example of space-based observatories complementing each other with the recent outburst of X-rays and gamma rays detected last August. The Swift satellite first noted the event on August 22, while the European Space Agency's XMM-Newton satellite began making detailed spectral studies of the radiation twelve hours later, followed by the Integral observatory. The outburst went on for more than four months, accompanied by hundreds of smaller bursts. The source for these events was a magnetar, a type of neutron star that is the most highly magnetized object known, with a magnetic field some 10,000 million times stronger than Earth's. The new magnetar, christened SGR 0501+4516, is of the type known as Soft Gamma-Ray Repeaters (SGR), and is the first such found in the last decade. Magnetars are known for spectacular periods of irregular burst activity, changing their luminosity up to ten orders of magnitude on timescales of just a few milliseconds. We occasionally discuss...

We think of the Allen Telescope Array, currently comprising only 42 of the 350 radio dishes planned, as a SETI instrument, capable of digging faint signals out of a wider field of stars than ever before. But the ATA is also engaged in an astrophysical survey of the sky at radio wavelengths, one that will look for radio bursts from supernovae. A glimpse of what it is looking for has just been reported in M82, a small irregular galaxy about twelve million light years from Earth. We're talking about a so-called 'radio supernova,' an exploding star undetectable by optical or X-ray telescopes. The new object is the brightest supernova seen in radio wavelengths in the last twenty years, and one of only a few dozen of its kind observed so far. And while the ATA will help us locate future radio objects of its kind, this one was found with the Very Large Array in New Mexico, and later confirmed through the NRAO's Very Long Baseline Array. Image (click to enlarge): Zooming into the center of...