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Hubble Telescope

Hubble telescope observations highlight dark matter’s weirdness – Space.com

Once again, scientists have realized that when it comes to dark matter, they are missing a piece or two of the puzzle.

Dark matter makes up more than a quarter of the universe, scientists have realized, but they haven’t yet learned how to see it directly. (The weird stuff doesn’t emit, absorb or reflect light, hence the name.) So they turn to effects they can see, like the way a clump of dark matter warps space around it, tweaking our view of objects on the other side. But according to a new study, some tiny clusters are distorting space much more than scientists had expected.

“There’s a feature of the real universe that we are simply not capturing in our current theoretical models,” Priyamvada Natarajana, a theoretical astrophysicist at Yale University and a coauthor on the new research, said in a statement. “This could signal a gap in our current understanding of the nature of dark matter and its properties, as these exquisite data have permitted us to probe the detailed distribution of dark matter on the smallest scales.”

Related: Dark matter and dark energy: The mystery explained (infographic)

These

These “galactic fireworks” are the colorful stars which make up the globular cluster NGC 1805, as seen in this photo taken by the Hubble Space Telescope. This cluster of thousands of stars is located out at the edge of the large Magellanic Cloud.  (Image credit: ESA/Hubble & NASA, J. Kalirai; CC BY 4.0)

The scientists behind the new research wanted to check how current theoretical models of dark matter stack up with the roundabout observations we can gather of it. So they turned to galaxy clusters, which hide a huge amount of dark matter.

“Galaxy clusters are ideal laboratories to understand if computer simulations of the universe reliably reproduce what we can infer about dark matter and its interplay with luminous matter,” Massimo Meneghetti, a cosmologist at the National Institute for Astrophysics in Italy and lead author on the new research, said in the statement.

The researchers used observations of three different galaxy clusters gathered by two instruments, the Hubble Space Telescope and the Very Large Telescope in Chile. The scientists mapped the dark matter within the clusters by noting how the material was warping light.

Among the large-scale distortions the astronomers were expecting to find, they also spotted smaller areas of warping, which they suspect mark the locations of individual, smaller cluster galaxies that hide concentrations of dark matter.

But when the researchers combined their map of dark matter with a model’s predictions of what dark matter might look like in cluster galaxies, the two landscapes didn’t line up. That means scientists still haven’t cracked the puzzle of how dark matter behaves.

The research is described in a paper published today (Sept. 11) in the journal Science.

Email Meghan Bartels at mbartels@space.com or follow her on Twitter @meghanbartels. Follow us on Twitter @Spacedotcom and on Facebook.

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Telescope uncovers

NASA telescope uncovers the cause of Betelgeuse’s mysterious dimming – CNET

a-plume-on-betelgeuse-artists-impression

Betelgeuse will go supernova and explode… eventually.


ESO

In the Before Times, when the coronavirus was only just beginning its grim march across the globe, our troubles were much farther away. About 640 light-years farther away, in fact. Astronomers observing Betelgeuse, a red supergiant star, had been puzzled by its mysterious dimming. Some believed the event, which lasted from November 2019 to February 2020, was a portent of doom signaling the star’s upcoming explosion. But then the dimming abruptly stopped.

Thanks to observations by NASA’s Hubble telescope, we might know why.

A new study, published in The Astrophysical Journal on Thursday (and accessible at arXiv), examined ultraviolet light emitted by Betelgeuse during the “Great Dimming” event using the Hubble Space Telescope. Fortunately, the event occurred just as Hubble scientists were looking to observe Betelgeuse with the telescope, providing a chance to understand why the star had begun to go dark.

From the cosmos to your inbox. Get the latest space stories from CNET every week.

Betelgeuse is a massive star, about 700 times bigger than our sun. If you dropped it into our solar system, it would swallow Mercury, Venus, Earth, Mars, the asteroid belt’s various worlds whole and Jupiter would end up as a snack, too. And it’s coming to the end of its life cycle, sometime in the next 100,000 years. When the supergiant started to dim last year, there were some believers who thought the process of exploding may have begun. 

A NASA graphic showing how a dust cloud might obscure the view of Betelgeuse.


NASA/ESA/E. Wheatley (STScI)

The Hubble observations suggest differently. By looking at Betelgeuse at UV wavelengths, researchers were able to get a better look at the star’s surface and atmosphere. They discovered a mass of bright, hot material moving outward from the southern hemisphere of the star at around 200,000 miles per hour and eventually being ejected into space.

“This material was two to four times more luminous than the star’s normal brightness,” said Andrea Dupree, associate director at the Harvard-Smithsonian Center for Astrophysics and lead author on the study, in a NASA release. About a month after the outburst, the south part of Betelgeuse dimmed conspicuously, she said.

Dupree and her team believe this material may have begun to cool down as it moved through space, forming a dense dust cloud that partially obscured Betelgeuse. It just so happens that Earth was in the perfect position to “see” the dust cloud front on, as if Betelgeuse shot the dust cloud directly at us. If it happened on the opposite side of Betelgeuse, we’d likely never even know.

Explosive outbursts are expected from star’s at the end of their life and when they die or “go supernova,” they release a shockwave that spews elements into space. The activity is critical to fill space with heavy elements like carbon, which then can become new stars elsewhere in the universe, so these stars are critical to the cosmic Circle of Life. 

Betelgeuse is still acting a little weird, however. Observations by NASA’s Stereo spacecraft observed the supergiant between late June and early August and noticed Betelgeuse was unexpectedly dimming again. NASA notes further observations will be undertaken in late August, when the star returns to the night sky and can be seen by telescopes again. 

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Telescope uncovers

NASA telescope uncovers the cause of Betelgeuse’s mysterious dimming – CNET

a-plume-on-betelgeuse-artists-impression

Betelgeuse will go supernova and explode… eventually.


ESO

In the Before Times, when the coronavirus was only just beginning its grim march across the globe, our troubles were much farther away. About 640 light-years farther away, in fact. Astronomers observing Betelgeuse, a red supergiant star, had been puzzled by its mysterious dimming. Some believed the event, which lasted from Nov. 2019 to Feb. 2020, was a portent of doom signalling the star’s upcoming explosion. But then the dimming abruptly stopped.

Thanks to observations by NASA’s Hubble telescope, we might know why.

A new study, published in The Astrophysical Journal on Thursday (and accessible at arXiv), examined ultraviolet light emitted by Betelgeuse during the “Great Dimming” event using the Hubble Space Telescope. Fortunately, the dimming event occurred just as Hubble scientists were looking to observe Betelgeuse with the telescope, providing a chance to understand why the star had begun to go dark.

From the cosmos to your inbox. Get the latest space stories from CNET every week.

Betelgeuse is a massive star, about 700 times bigger than our sun. If you dropped it into our solar system, it would swallow Mercury, Venus, Earth, Mars, the asteroid belt’s various worlds whole and Jupiter would end up as a snack, too. And it’s coming to the end of its life cycle, sometime in the next 100,000 years. When the supergiant started to dim last year, there were some believers who thought the process of exploding may have begun. 

A NASA graphic showing how a dust cloud might obscure the view of Betelgeuse.


NASA/ESA/E. Wheatley (STScI)

The Hubble observations suggest differently. By looking at Betelgeuse at UV wavelengths, researchers were able to get a better look at the star’s surface and atmosphere. They discovered a mass of bright, hot material moving outward from the southern hemisphere of the star at around 200,000 miles per hour and eventually being ejected into space.

“This material was two to four times more luminous than the star’s normal brightness,” said Andrea Dupree, associate director at the Harvard-Smithsonian Center for Astrophysics and lead author on the study, in a NASA release. About a month after the outburst, the south part of Betelgeuse dimmed conspicuously, she said.

Dupree and her team believe this material may have begun to cool down as it moved through space, forming a dense dust cloud that partially obscured Betelgeuse. It just so happens that Earth was in the perfect position to “see” the dust cloud front on, as if Betelgeuse shot the dust cloud directly at us. If it happened on the opposite side of Betelgeuse, we’d likely never even know.

Explosive outbursts are expected from star’s at the end of their life and when they die or “go supernova,” they release a shockwave that spews elements into space. The activity is critical to fill space with heavy elements like carbon, which then can become new stars elsewhere in the universe, so these stars are critical to the cosmic Circle of Life. 

Betelgeuse is still acting a little weird, however. Observations by NASA’s Stereo spacecraft observed the supergiant between late June and early August and noticed Betelgeuse was unexpectedly dimming again. NASA notes further observations will be undertaken in late August, when the star returns to the night sky and can be seen by telescopes again. 

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space Telescope

Webb Space Telescope Launch Delayed Until 2021 – NPR

In 2017, technicians lift the mirror assembly of the James Webb Space Telescope using a crane inside a clean room at NASA’s Goddard Space Flight Center in Greenbelt, Md.

NASA/AP


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NASA/AP

In 2017, technicians lift the mirror assembly of the James Webb Space Telescope using a crane inside a clean room at NASA’s Goddard Space Flight Center in Greenbelt, Md.

NASA/AP

The launch of the James Webb Space Telescope, the long-awaited — and long-delayed — successor to the Hubble Space Telescope, has been pushed back yet another seven months, NASA said Thursday citing, in part, delays from the COVID-19 pandemic.

The nearly $10 billion project, which scientists hope will see back to the time when the first galaxies were formed following the Big Bang, had been scheduled to launch next March from French Guiana atop an Ariane 5 rocket, but the space agency said it is now aiming for an Oct. 31, 2021, launch date.

“Webb is the world’s most complex space observatory, and our top science priority, and we’ve worked hard to keep progress moving during the pandemic,” Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate at the agency’s headquarters in Washington, D.C., said in a statement. “The team continues to be focused on reaching milestones and arriving at the technical solutions that will see us through to this new launch date next year.”

NASA said disruption to work shifts caused by COVID-19 work-from-home orders and other technical challenges had combined to push back the scheduled launch.

The telescope has experienced numerous delays and cost overruns since the project first went into development in 1996. Initial estimates were that it would cost between $1 billion and $3.5 billion with a possible launch in 2007.

In January, after years of setbacks and ballooning costs, a Government Accountability Office report concluded that the project’s estimated cost was $9.7 billion, an increase of 95%. At the time, the GAO gave NASA a low probability of meeting its then-March 2021 launch date.

Despite the latest delay, NASA’s Webb program director, Gregory Robinson, said it would be able to stay within its development cost cap.

“Based on current projections, the program expects to complete the remaining work within the new schedule without requiring additional funds,” Robinson said. “Although efficiency has been affected and there are challenges ahead, we have retired significant risk through the achievements and good schedule performance over the past year.”

Built by Northrup Grumman and Ball Aerospace, Webb — named after the NASA administrator who was instrumental in overseeing the agency’s Apollo moon program — boasts a 6.5-meter (21-foot) segmented mirror, considerably larger and more sensitive than Hubble’s 2.4 meter (7.9-foot) primary mirror.

Unlike Hubble, which was placed in low-Earth orbit, the Webb Space Telescope will be parked at a position known as Lagrange Point 2 (L2), keeping the Earth between it and the sun. Along with a built-in heat shield, Webb’s position in space is meant to help protect the spacecraft’s instruments for detecting infrared light from the intense heat of the sun.

Also unlike Hubble, which was launched in 1990 with faulty optics that were later fixed in a space shuttle servicing mission and was routinely upgraded by NASA astronauts, the Webb Space Telescope, at about 1 million miles from Earth, will be on its own if anything goes wrong.

Webb will be launched in a folded-up configuration. About 30 minutes into its flight, the spacecraft will begin a complex, weeks-long unfolding process to extend its sun shield and mirror.

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