This animation of Jupiter is made from more than 1,000 images taken by 91 amateurs from around the world between the 19th of December 2014 and the 31st of March 2015.
A photo of Saturn and Titan crossing the galactic plane near the galactic center, taken by astrophotographer Damian Peach on May 2, 2017.
Early System Evolution: The Disks around Epsilon Eridani
Epsilon Eridani is a bit over 10 light years from the Sun, and about a fifth of its age, meaning we have close at hand a stellar system that can help us understand what our own Solar System was like in its youth.
The new paper confirms Marengo’s earlier findings that there are separate inner and outer disk structures, with the possibility that the inner disk is itself made up of more than one debris belt.
The cosmic swirl and slosh of giant waves in an enormous reservoir of glowing hot gas are traced in this enhanced X-ray image from the Chandra Observatory. The frame spans over 1 million light-years across the center of the nearby Perseus Galaxy Cluster, some 240 million light-years distant. Like other clusters of galaxies, most of the observable mass in the Perseus cluster is in the form of the cluster-filling gas. With temperatures in the tens of millions of degrees, the gas glows brightly in X-rays. Computer simulations can reproduce details of the structures sloshing through the Perseus cluster’s X-ray hot gas, including the remarkable concave bay seen below and left of center. About 200,000 light-years across, twice the size of the Milky Way, the bay’s formation indicates that Perseus itself was likely grazed by a smaller galaxy cluster billions of years ago.
New CAST limit on the axion–photon interaction
Hypothetical low-mass particles, such as axions, provide a compelling explanation for the dark matter in the universe. Such particles are expected to emerge abundantly from the hot interior of stars. To test this prediction, the CERN Axion Solar Telescope (CAST) uses a 9 T refurbished Large Hadron Collider test magnet directed towards the Sun. In the strong magnetic field, solar axions can be converted to X-ray photons which can be recorded by X-ray detectors. In the 2013–2015 run, thanks to low-background detectors and a new X-ray telescope, the signal-to-noise ratio was increased by about a factor of three. Here, we report the best limit on the axion–photon coupling strength (0.66 × 10−10 GeV−1 at 95% confidence level) set by CAST, which now reaches similar levels to the most restrictive astrophysical bounds.
It’s springtime and the deployed primary mirror of NASA’s James Webb Space Telescope looks like a spring flower in full bloom.
In this photo, NASA technicians lifted the telescope using a crane and moved it inside a clean room at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Once launched into space, the Webb telescope’s 18-segmented gold mirror is specially designed to capture infrared light from the first galaxies that formed in the early universe, and will help the telescope peer inside dust clouds where stars and planetary systems are forming today.
Asteroid 2014 JO25
A day before its closest approach, asteroid 2014 JO25 was imaged by radar with the 70-meter antenna of NASA’s Goldstone Deep Space Communications Complex in California. This grid of 30 radar images, top left to lower right, reveals the two-lobed shape of the asteroid that rotates about once every five hours. Its largest lobe is about 610 meters across. On the list of Potentially Hazardous Asteroids, this space rock made its close approach to our fair planet on April 19, flying safely past at a distance of 1.8 million kilometers.
Potentially Habitable Super-Earth is a Prime Target for Atmospheric Study
Located just 40 light-years away, the planet was found using the transit method, in which a star dims as a planet crosses in front of it as seen from Earth. By measuring how much light this planet blocks, the team determined that it is about 11,000 miles in diameter, or about 40 percent larger than Earth.
The researchers have also weighed the planet to be 6.6 times the mass of Earth, showing that it is dense and likely has a rocky composition. Small, potentially habitable planets have been found in the TRAPPIST-1 system, located a similar distance from Earth, but only one of those worlds has had its density measured accurately, showing that it isn’t rocky. Therefore, some or all of the others also might not be rocky.
Since this planet transits its star, unlike the closest world to the solar system Proxima Centauri b, it can be examined for the presence of air. As the planet moves in front of the star, the star’s light will be filtered through any atmosphere and leave an imprint. Large, next-generation telescopes will be needed to tease out these subtle signals.
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The planet orbits a tiny, faint star known as LHS 1140, which is only one-fifth the size of the Sun. Since the star is so dim and cool, its habitable zone (the distance at which a planet might be warm enough to hold liquid water) is very close. This planet, designated LHS 1140 b, orbits its star every 25 days. At that distance, it receives about half as much sunlight from its star as Earth.
In the earliest (so-called “Class 0”) phase of Sun-like (low-mass) star formation, circumstellar disks are expected to form, feeding the protostars. However, these disks are difficult to resolve spatially because of their small sizes. Moreover, there are theoretical difficulties in producing these disks in the earliest phase because of the retarding effects of magnetic fields on the rotating, collapsing material (so-called “magnetic braking”). With the Atacama Large Millimeter/submillimeter Array (ALMA), it becomes possible to uncover these disks and study them in detail. HH 212 is a very young protostellar system. With ALMA, we not only detect but also spatially resolve its disk in dust emission at submillimeter wavelength. The disk is nearly edge-on and has a radius of ~60 astronomical unit. It shows a prominent equatorial dark lane sandwiched between two brighter features due to relatively low temperature and high optical depth near the disk midplane. For the first time, this dark lane is seen at submillimeter wavelength, producing a “hamburger”-shaped appearance that is reminiscent of the scattered-light image of an edge-on disk in optical and near infrared light.
![A Cosmic Burst Repeats, Deepening a Mystery“A minor point of interest regarding the Spitler Burst.” The email subject line popped up on Shami Chatterjee’s computer screen just after 3 in the afternoon on Nov. 5, 2015.
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For nearly a decade,...](https://64.media.tumblr.com/34e2cbc7fe4f72bfb3a799ab4f142744/tumblr_oomhan7Tg41t8pecvo1_1280.gifv)
A Cosmic Burst Repeats, Deepening a Mystery
A minor point of interest regarding the Spitler Burst.” The email subject line popped up on Shami Chatterjee’s computer screen just after 3 in the afternoon on Nov. 5, 2015.
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For nearly a decade, Chatterjee and other astrophysicists on the thread had been trying to understand the nature of short, superenergetic flashes of radio waves in space. These “fast radio bursts,” or FRBs, last just a few milliseconds, but they are the most luminous radio signals in the universe, powered by as much energy as 500 million suns. The first one was spotted in 2007 by the astronomer Duncan Lorimer, who together with one of his students stumbled upon the signal accidentally in old telescope data; at the time, few believed it. Skeptics suspected interference from mobile phones or microwave ovens. But more and more FRBs kept showing up — 26 have been counted so far, including the Spitler burst, detected by the astronomer Laura Spitler in data from 2012 — and scientists had to agree they were real.
The question was, what causes them? Researchers sketched dozens of models, employing the gamut of astrophysical mysteries — from flare stars in our own galaxy to exploding stars, mergers of charged black holes, white holes, evaporating black holes, oscillating primordial cosmic strings, and even aliens sailing through the cosmos using extragalactic light sails. For scientists, the FRBs were as blinding as flash grenades in a dark forest; their power, brevity and unpredictability simply made it impossible to see the source of the light.
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And suddenly, just like that, Scholz had spotted a repeater. The discovery was “both amazing and terrifying,” Chatterjee said — amazing, because “everyone knew that FRBs don’t repeat,” and terrifying because of the gargantuan energy required to produce even one of these bursts. Perhaps the only thing fiercer than emitting the energy of 500 million suns is doing it again.
Waterloo researchers capture first “image” of a dark matter web that connects galaxies
As part of their research, Hudson and co-author Seth Epps, a master’s student at the University of Waterloo at the time, used a technique called weak gravitational lensing, an effect that causes the images of distant galaxies to warp slightly under the influence of an unseen mass such as a planet, a black hole, or in this case, dark matter. The effect was measured in images from a multi-year sky survey at the Canada-France-Hawaii Telescope.
They combined lensing images from more than 23,000 galaxy pairs located 4.5 billion light-years away to create a composite image or map that shows the presence of dark matter between the two galaxies. Results show the dark matter filament bridge is strongest between systems less than 40 million light years apart.
The Great Cold Spot in Jupiter’s upper atmosphere
Past observations and modeling of Jupiter’s thermosphere have, due to their limited resolution, suggested that heat generated by the aurora near the poles results in a smooth thermal gradient away from these aurorae, indicating a quiescent and diffuse flow of energy within the subauroral thermosphere. Here we discuss Very Large Telescope-Cryogenic High-Resolution IR Echelle Spectrometer observations that reveal a small-scale localized cooling of ~200 K within the nonauroral thermosphere. Using Infrared Telescope Facility NSFCam images, this feature is revealed to be quasi-stable over at least a 15 year period, fixed in magnetic latitude and longitude. The size and shape of this “Great Cold Spot” vary significantly with time, strongly suggesting that it is produced by an aurorally generated weather system: the first direct evidence of a long-term thermospheric vortex in the solar system. We discuss the implications of this spot, comparing it with short-term temperature and density variations at Earth.
An ‘Earth-sized’ telescope takes aim at the first-ever image of a black hole
For years, scientists have created illustrations of black holes, but actual images of the light-absorbing phenomena have remained elusive. The Event Horizon Telescope might be changing that as you read these words.
The EHT is a collaboration of eight radio telescopes located around the world. For a handful of nights between April 4 and 15, scientists in Mexico, Spain and even Antarctica will train their radio observatories toward Sagittarius A*, the supermassive black hole at the center of the Milky Way galaxy, to measure what some astronomers describe as the holy grail: the event horizon.
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EHT’s collective of international observatories creates a “virtual telescope” approximately the size of Earth. The NewsHour visited one of the sites — Atacama Large Millimeter/submillimeter Array high in Chile’s Atacama desert — more than two years ago, when the EHT wasn’t fully operational yet.
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