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New Hubble Data Explains Missing Dark Matter

Hubble Space Telescope photo illustration (stock image; elements furnished by NASA).
Credit: © Vadimsadovski / stock.adobe.com 

Source: Science Daily

The missing dark matter in certain galaxies can be explained by the effects of tidal disruption: the gravity forces of a neighboring massive galaxy, literally tearing the smaller galaxy apart.

In 2018 an international team of researchers using the NASA/ESA Hubble Space Telescope and several other observatories uncovered, for the first time, a galaxy in our cosmic neighborhood that is missing most of its dark matter. This discovery of the galaxy NGC 1052-DF2 was a surprise to astronomers, as it was understood that dark matter is a key constituent in current models of galaxy formation and evolution. In fact, without the presence of dark matter, the primordial gas would lack enough gravitational pull to start collapsing and forming new galaxies. A year later, another galaxy that misses dark matter was discovered, NGC 1052-DF4, which further triggered intense debates among astronomers about the nature of these objects.

Now, new Hubble data have been used to explain the reason behind the missing dark matter in NGC 1052-DF4, which resides 45 million light-years away. Mireia Montes of the University of New South Wales in Australia led an international team of astronomers to study the galaxy using deep optical imaging. They discovered that the missing dark matter can be explained by the effects of tidal disruption. The gravity forces of the neighboring massive galaxy NGC 1035 are tearing NGC 1052-DF4 apart. During this process, the dark matter is removed, while the stars feel the effects of the interaction with another galaxy at a later stage.

Until now, the removal of dark matter in this way has remained hidden from astronomers as it can only be observed using extremely deep images that can reveal extremely faint features. “We used Hubble in two ways to discover that NGC 1052-DF4 is experiencing an interaction,” explained Montes. “This includes studying the galaxy’s light and the galaxy’s distribution of globular clusters.”

Thanks to Hubble’s high resolution, the astronomers could identify the galaxy’s globular cluster population. The 10.4-meter Gran Telescopio Canarias (GTC) telescope and the IAC80 telescope in the Canary Islands of Spain were also used to complement Hubble’s observations by further studying the data.

“It is not enough just to spend a lot of time observing the object, but a careful treatment of the data is vital,” explained team member Raúl Infante-Sainz of the Instituto de Astrofísica de Canarias in Spain. “It was therefore important that we use not just one telescope/instrument, but several (both ground- and space-based) to conduct this research. With the high resolution of Hubble, we can identify the globular clusters, and then with GTC photometry we obtain the physical properties.”

Globular clusters are thought to form in the episodes of intense star formation that shaped galaxies. Their compact sizes and luminosity make them easily observable, and they are therefore good tracers of the properties of their host galaxy. In this way, by studying and characterizing the spatial distribution of the clusters in NGC 1052-DF4, astronomers can develop insight into the present state of the galaxy itself. The alignment of these clusters suggests they are being “stripped” from their host galaxy, and this supports the conclusion that tidal disruption is occurring.

By studying the galaxy’s light, the astronomers also found evidence of tidal tails, which are formed of the material moving away from NGC 1052-DF4. This further supports the conclusion that this is a disruption event. The additional analysis concluded that the central parts of the galaxy remain untouched and only about 7% of the stellar mass of the galaxy is hosted in these tidal tails. This means that dark matter, which is less concentrated than stars, was previously and preferentially stripped from the galaxy, and now the outer stellar component is starting to be stripped as well.

“This result is a good indicator that, while the dark matter of the galaxy was evaporated from the system, the stars are only now starting to suffer the disruption mechanism,” explained team member Ignacio Trujillo of the Instituto de Astrofísica de Canarias in Spain. “In time, NGC 1052-DF4 will be cannibalized by the large system around NGC 1035, with at least some of their stars floating free in deep space.”

The discovery of evidence to support the mechanism of tidal disruption as the explanation for the galaxy’s missing dark matter has not only solved an astronomical conundrum but has also brought a sigh of relief to astronomers. Without it, scientists would be faced with having to revise our understanding of the laws of gravity.

“This discovery reconciles existing knowledge of how galaxies form and evolve with the most favorable cosmological model,” added Montes.


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Materials provided by NASA/Goddard Space Flight CenterNote: Content may be edited for style and length.





Hubble’s Incredible Photo of the Cygnus Loop

While appearing as a delicate and light veil draped across the sky, this image from the NASA/ESA Hubble Space Telescope actually depicts a small section of the Cygnus supernova blast wave, located around 2600 light-years away. Credit: ESA/Hubble & NASA, W. Blair.

Source: Universe Today

If you’re a Star Trek fan, you may think the above image portrays the “Nexus” from the movie Star Trek: Generations. In the film, the Nexus was a ribbon-like extra-dimensional realm that exists outside of normal space-time.

But this is actually a real image from the venerable Hubble Space Telescope, of the Cygnus Loop. This stunning picture from space shows just a small portion of a blast wave leftover from a supernova that took place, from our vantage point, in the northern constellation Cygnus the Swan.

The original supernova explosion blasted apart a dying star about 2,600 light-years away. This star was approximately 20 times more massive than our Sun, and the blast likely occurred between 10,000 to 20,000 years ago. Since then, the remnant has expanded 60 light-years from its center.

The shockwave marks the outer edge of the supernova remnant and continues to expand at incredible speeds, around 350 kilometers per second. The interaction of the ejected material and the low-density interstellar material swept up by the shockwave forms the distinctive veil-like structure seen in this image.

In Star Trek lore, if you were inside the Nexus, you existed in a perfect, idealized world. Staring at an incredible image like this makes you consider that something like that might just be possible.

Here’s another, previous Hubble image of the Cygnus Loop supernova remnant from 1991, and below that is an image of the famous Veil Nebula, which is inside the larger Cygnus supernova remnant.

Cygnus Loop Supernova Remnant

This 1991 image from NASA’s Hubble Space Telescope captures a small section of the Cygnus Loop supernova remnant. Credit: NASA/Hubble

Veil Nebula. Image credit: ESA/Hubble Space Telescope

Source: ESA




The Secret Behind Those Beautiful Hubble Images

Video Source: SciShow Space

Since it launched in 1990, the Hubble Space Telescope has snapped more than a million images and changed the way we see the universe, literally. Here’s why the Hubble images and the technology are so unique.



New Hubble Measurements Confirm Universe Is Expanding Faster Than Expected

This is a ground-based telescope’s view of the Large Magellanic Cloud, a satellite galaxy of our Milky Way. The inset image, taken by the Hubble Space Telescope, reveals one of many star clusters scattered throughout the dwarf galaxy.
Credit: NASA, ESA, Adam Riess, and Palomar Digitized Sky Survey

Source: Science Daily

New measurements from NASA’s Hubble Space Telescope confirm that the Universe is expanding about 9% faster than expected based on its trajectory seen shortly after the big bang, astronomers say.

The new measurements, published April 25 in the Astrophysical Journal Letters, reduce the chances that the disparity is an accident from 1 in 3,000 to only 1 in 100,000 and suggest that new physics may be needed to better understand the cosmos.

“This mismatch has been growing and has now reached a point that is really impossible to dismiss as a fluke. This is not what we expected,” says Adam Riess, Bloomberg Distinguished Professor of Physics and Astronomy at The Johns Hopkins University, Nobel Laureate and the project’s leader.

In this study, Riess and his SH0ES (Supernovae, H0, for the Equation of State) Team analyzed light from 70 stars in our neighboring galaxy, the Large Magellanic Cloud, with a new method that allowed for capturing quick images of these stars. The stars, called Cepheid variables, brighten and dim at predictable rates that are used to measure nearby intergalactic distances.

The usual method for measuring the stars is incredibly time-consuming; the Hubble can only observe one star for every 90-minute orbit around Earth. Using their new method called DASH (Drift And Shift), the researchers using Hubble as a “point-and-shoot” camera to look at groups of Cepheids, thereby allowing the team to observe a dozen Cepheids in the same amount of time it would normally take to observe just one.

With this new data, Riess and the team were able to strengthen the foundation of the cosmic distance ladder, which is used to determine distances within the Universe, and calculate the Hubble constant, a value of how fast the cosmos expands over time.

The team combined their Hubble measurements with another set of observations, made by the Araucaria Project, a collaboration between astronomers from institutions in Chile, the U.S., and Europe. This group made distance measurements to the Large Magellanic Cloud by observing the dimming of light as one star passes in front of its partner in eclipsing binary-star systems.

The combined measurements helped the SH0ES team refine the Cepheids’ true brightness. With this more accurate result, the team could then “tighten the bolts” of the rest of the distance ladder that uses exploding stars called supernovae to extend deeper into space.

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The Universe Is Expanding Faster Than Expected

Source: Science Daily

Astronomers have used NASA’s Hubble Space Telescope to make the most precise measurements of the expansion rate of the universe since it was first calculated nearly a century ago. Intriguingly, the results are forcing astronomers to consider that they may be seeing evidence of something unexpected at work in the universe.

That’s because the latest Hubble finding confirms a nagging discrepancy showing the universe to be expanding faster now than was expected from its trajectory seen shortly after the big bang. Researchers suggest that there may be new physics to explain the inconsistency.

“The community is really grappling with understanding the meaning of this discrepancy,” said lead researcher and Nobel Laureate Adam Riess of the Space Telescope Science Institute (STScI) and Johns Hopkins University, both in Baltimore, Maryland.

Riess’s team, which includes Stefano Casertano, also of STScI and Johns Hopkins, has been using Hubble over the past six years to refine the measurements of the distances to galaxies, using their stars as milepost markers. Those measurements are used to calculate how fast the universe expands with time, a value known as the Hubble constant. The team’s new study extends the number of stars analyzed to distances up to 10 times farther into space than previous Hubble results.

But Riess’s value reinforces the disparity with the expected value derived from observations of the early universe’s expansion, 378,000 years after the big bang — the violent event that created the universe roughly 13.8 billion years ago. Those measurements were made by the European Space Agency’s Planck satellite, which maps the cosmic microwave background, a relic of the big bang. The difference between the two values is about 9 percent. The new Hubble measurements help reduce the chance that the discrepancy in the values is a coincidence to 1 in 5,000.

Planck’s result predicted that the Hubble constant value should now be 67 kilometers per second per megaparsec (3.3 million light-years), and could be no higher than 69 kilometers per second per megaparsec. This means that for every 3.3 million light-years farther away a galaxy is from us, it is moving 67 kilometers per second faster. But Riess’s team measured a value of 73 kilometers per second per megaparsec, indicating galaxies are moving at a faster rate than implied by observations of the early universe.

The Hubble data are so precise that astronomers cannot dismiss the gap between the two results as errors in any single measurement or method. “Both results have been tested multiple ways, so barring a series of unrelated mistakes,” Riess explained, “it is increasingly likely that this is not a bug but a feature of the universe.”

Explaining a Vexing Discrepancy

Riess outlined a few possible explanations for the mismatch, all related to the 95 percent of the universe that is shrouded in darkness. One possibility is that dark energy, already known to be accelerating the cosmos, maybe shoving galaxies away from each other with even greater — or growing — strength. This means that the acceleration itself might not have a constant value in the universe but changes over time in the universe. Riess shared a Nobel Prize for the 1998 discovery of the accelerating universe.

Another idea is that the universe contains a new subatomic particle that travels close to the speed of light. Such speedy particles are collectively called “dark radiation” and include previously known particles like neutrinos, which are created in nuclear reactions and radioactive decays. Unlike a normal neutrino, which interacts by a subatomic force, this new particle would be affected only by gravity and is dubbed a “sterile neutrino.”

Yet another attractive possibility is that dark matter (an invisible form of matter not made up of protons, neutrons, and electrons) interacts more strongly with normal matter or radiation than previously assumed.

Any of these scenarios would change the contents of the early universe, leading to inconsistencies in theoretical models. These inconsistencies would result in an incorrect value for the Hubble constant, inferred from observations of the young cosmos. This value would then be at odds with the number derived from the Hubble observations.

Riess and his colleagues don’t have any answers yet to this vexing problem, but his team will continue to work on fine-tuning the universe’s expansion rate. So far, Riess’s team, called the Supernova H0 for the Equation of State (SH0ES), has decreased the uncertainty to 2.3 percent. Before Hubble was launched in 1990, estimates of the Hubble constant varied by a factor of two. One of Hubble’s key goals was to help astronomers reduce the value of this uncertainty to within an error of only 10 percent. Since 2005, the group has been on a quest to refine the accuracy of the Hubble constant to a precision that allows for a better understanding of the universe’s behavior.

Building a Strong Distance Ladder

The team has been successful in refining the Hubble constant value by streamlining and strengthening the construction of the cosmic distance ladder, which the astronomers use to measure accurate distances to galaxies near to and far from Earth. The researchers have compared those distances with the expansion of space as measured by the stretching of light from receding galaxies. They then have used the apparent outward velocity of galaxies at each distance to calculate the Hubble constant.

But the Hubble constant’s value is only as precise as the accuracy of the measurements. Astronomers cannot use a tape measure to gauge the distances between galaxies. Instead, they have selected special classes of stars and supernovae as cosmic yardsticks or milepost markers to precisely measure galactic distances.

Among the most reliable for shorter distances are Cepheid variables, pulsating stars that brighten and dim at rates that correspond to their intrinsic brightness. Their distances, therefore, can be inferred by comparing their intrinsic brightness with their apparent brightness as seen from Earth.

Astronomer Henrietta Leavitt was the first to recognize the utility of Cepheid variables to gauge distances in 1913. But the first step is to measure the distances to Cepheids independent of their brightness, using a basic tool of geometry called parallax. Parallax is the apparent shift of an object’s position due to a change in an observer’s point of view. This technique was invented by the ancient Greeks who used it to measure the distance from Earth to the Moon.

The latest Hubble result is based on measurements of the parallax of eight newly analyzed Cepheids in our Milky Way galaxy. These stars are about 10 times farther away than any studied previously, residing between 6,000 light-years and 12,000 light-years from Earth, making them more challenging to measure. They pulsate at longer intervals, just like the Cepheids observed by Hubble in distant galaxies containing another reliable yardstick, exploding stars called Type Ia supernovae. This type of supernova flares with uniform brightness and is brilliant enough to be seen from relatively farther away. Previous Hubble observations studied 10 faster-blinking Cepheids located 300 light-years to 1,600 light-years from Earth.

Scanning the Stars

To measure parallax with Hubble, the team had to gauge the apparent tiny wobble of the Cepheids due to Earth’s motion around the Sun. These wobbles are the size of just 1/100 of a single-pixel on the telescope’s camera, which is roughly the apparent size of a grain of sand seen 100 miles away.

Therefore, to ensure the accuracy of the measurements, the astronomers developed a clever method that was not envisioned when Hubble was launched. The researchers invented a scanning technique in which the telescope measured a star’s position a thousand times a minute every six months for four years.

The team calibrated the true brightness of the eight slowly pulsating stars and cross-correlated them with their more distant blinking cousins to tighten the inaccuracies in their distance ladder. The researchers then compared the brightness of the Cepheids and supernovae in those galaxies with better confidence, so they could more accurately measure the stars’ true brightness, and therefore calculate distances to hundreds of supernovae in far-flung galaxies with more precision.

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Scientists Find Dozens of ‘Invisible’ Galaxies, Changing Our Understanding of the Universe

Image Credit: Thee Mind Unleashed

Elias Marat | The Mind Unleashed

Using the combined power of multiple astronomical observatories across the world, astronomers have discovered a stunning set of 39 massive galaxies that had previously been invisible.

The multiple discovery is the first of its kind, according to a study published on Wednesday in Nature, and is set to forever change the way in which scientists look at how galaxies are formed.

The galaxies, which are located billions of light-years away, are intimately connected with supermassive black holes and the distribution of dark matter.

In a press release, lead researcher Tao Wang at the University of Tokyo said:

“This is the first time that such a large population of massive galaxies was confirmed during the first 2 billion years of the 13.7-billion-year life of the universe. These were previously invisible to us … This finding contravenes current models for that period of cosmic evolution and will help to add some details, which have been missing until now.”

And while the Hubble Space Telescope has allowed astronomers to gain major insights into previously unknown parts of the universe, the research team from the University of Tokyo relied on the Atacama Large Millimeter/submillimeter Array (ALMA) telescope in Chile to uncover this latest massive find.

And it appears that the huge galaxies would overwhelm our humble view of the heavens if they were actually visible to us humans. Given the age and distance of the huge galaxies, they have always been hidden from our view thanks to the weak and stretched light emanating from them. As a result of such distance, the visible light becomes infrared.

Kotaro Kohno, the study’s author and a professor at the University of Tokyo, explained:

“The light from these galaxies is very faint with long wavelengths invisible to our eyes and undetectable by Hubble.


So we turned to the Atacama Large Millimeter/submillimeter Array (ALMA), which is ideal for viewing these kinds of things. I have a long history with that facility and so knew it would deliver good results.”

The infrared light from the distant galaxies was originally revealed by the NASA Spitzer Space Telescope before ALMA’s “sharp eyes” detected them, cutting through the thick dust that obscured them from our sight, Wang explained.

“It took further data from the imaginatively named Very Large Telescope in Chile to really prove we were seeing ancient massive galaxies where none had been seen before.”

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Shining Starlight on the Search For Life

Unknown planet in outer space. 3D illustration.

By Miles Hatfield | Phys.org

In the hunt for life on other worlds, astronomers scour over planets that are light-years away. They need ways to identify life from afar—but what counts as good evidence?

Our own planet provides some inspiration. Microbes fill the air with methane; photosynthesizing plants expel oxygen. Perhaps these gases might be found wherever life has taken hold.

But on worlds very different from our own, putative signs of life can be stirred up by non-biological processes. To know a true sign when you see it, astronomer Kevin France at the University of Colorado, Boulder, says, you must look beyond the planet itself, all the way to the gleaming star it orbits.

To this end, France and his team designed the SISTINE mission. Flying on a sounding rocket for a 15-minute flight, it will observe far-off stars to help interpret signs of life on the planets that orbit them. The mission will launch from the White Sands Missile Range in New Mexico in the early morning hours of Aug. 5, 2019.

When Earth Is a Bad Example

Shortly after Earth formed 4.6 billion years ago, it was enveloped by a noxious atmosphere. Volcanoes spewed methane and sulfur. The air teemed with up to 200 times more  than today’s levels.

It wasn’t for another billion and a half years that molecular oxygen, which contains two oxygen atoms, entered the scene. It was a waste product, discarded by ancient bacteria through photosynthesis. But it kick-started what became known as the Great Oxidization Event, permanently changing Earth’s atmosphere and paving the way for more complex lifeforms.

Shining (star)light on the search for life

The young Earth’s atmosphere might have looked like this artist’s interpretation — a pale orange dot. Credit: NASA/GSFC/F. Reddy 

“We would not have large amounts of oxygen in our atmosphere if we didn’t have that surface life,” France said.

Oxygen is known as a biomarker: a chemical compound associated with life. Its presence in Earth’s atmosphere hints at the lifeforms lurking below. But as sophisticated computer models have now shown, biomarkers on Earth aren’t always so trustworthy for exoplanets, or planets orbiting stars elsewhere in the universe.

France points to M-dwarf stars to make this case. Smaller and colder than our Sun, M-dwarfs account for nearly three-quarters of the Milky Way’s stellar population. To understand exoplanets that orbit them, scientists simulated Earth-sized planets circling M-dwarfs. Differences from Earth quickly emerged.

M-dwarfs generate intense ultraviolet light. When that light struck the simulated Earth-like planet, it ripped the carbon from carbon dioxide, leaving behind free molecular oxygen. The UV light also broke up molecules of water vapor, releasing single oxygen atoms. The atmospheres created oxygen—but without life.

“We call these false-positive biomarkers,” France said. “You can produce oxygen on an Earth-like planet through photochemistry alone.”

Earth’s low oxygen levels without life were a kind of a fluke—thanks, in part, to our interaction with our Sun. Exoplanet systems with different stars might be different. “If we think we understand a planet’s atmosphere but don’t understand the star it orbits, we’re probably going to get things wrong,” France said.

Shining (star)light on the search for life

The Hubble Space Telescope captured this image of Planetary Nebula NGC 6826 Jan. 27, 1996. SISTINE will image NGC 6826 during its first flight to calibrate its instruments. Credit: HST/NASA/ESA 

To Know a Planet, Study its Star

France and his team designed SISTINE to better understand host stars and their effects on exoplanet atmospheres. Short for Suborbital Imaging Spectrograph for Transition region Irradiance from Nearby Exoplanet host stars, SISTINE measures the high-energy radiation from these stars. With knowledge about host stars’ spectra, scientists can better distinguish true biomarkers from false-positives on their orbiting planets.

To make these measurements, SISTINE uses a spectrograph, an instrument that separates light into its component parts.

“Spectra are like fingerprints,” said Jane Rigby, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who uses the methodology. “It’s how we find out what things are made of, both on our planet and as we look out into the universe.”

SISTINE measures spectra in wavelengths from 100 to 160 nanometers, a range of far-UV light that, among other things, can create oxygen, possibly generating a false-positive. Light output in this range varies with the mass of the star—meaning stars of different masses will almost surely differ from our Sun.

SISTINE can also measure flares, or bright stellar explosions, which release intense doses of far-UV light all at once. Frequent flares could turn a habitable environment into a lethal one.

The SISTINE mission will fly on a Black Brant IX sounding rocket. Sounding rockets make short, targeted flights into space before falling back to Earth; SISTINE’s flight gives it about five minutes observing time. Though brief, SISTINE can see stars in wavelengths inaccessible to observatories like the Hubble Space Telescope.

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Hubble Spots a Stunning Spiral Galaxy 30 Million Light-Years Away

NGC 2903 is located about 30 million light-years away in the constellation of Leo (the Lion) and was studied as part of a Hubble survey of the central regions of roughly 145 nearby disk galaxies.
Credit: ESA/Hubble & NASA, L. Ho et al.

Source: Science Daily

Few of the universe’s residents are as iconic as the spiral galaxy. These limelight-hogging celestial objects combine whirling, pinwheeling arms with scatterings of sparkling stars, glowing bursts of gas, and dark, weaving lanes of cosmic dust, creating truly awesome scenes — especially when viewed through a telescope such as the NASA/ESA Hubble Space Telescope. In fact, this image from Hubble frames a perfect spiral specimen: the stunning NGC 2903.

NGC 2903 is located about 30 million light-years away in the constellation of Leo (the Lion) and was studied as part of a Hubble survey of the central regions of roughly 145 nearby disk galaxies. This study aimed to help astronomers better understand the relationship between the black holes that lurk at the cores of galaxies like these, and the rugby-ball-shaped bulge of stars, gas, and dust at the galaxy’s center — such as that seen in this image.

Read more great articles at Science Daily.




Einstein’s General Theory of Relativity Confirmed By Researchers Aided By a White Dwarf

This illustration reveals how the gravity of a white dwarf star warps space and bends the light of a distant star behind it. Credit: NASA, ESA, and A. Feild (STScI)

Source: phys.org

Albert Einstein predicted that whenever light from a distant star passes by a closer object, gravity acts as a kind of magnifying lens, brightening and bending the distant starlight. Yet, in a 1936 article in the journal Science, he added that because stars are so far apart “there is no hope of observing this phenomenon directly.”

Now, an international research team directed by Kailash C. Sahu has done just that, as described in their June 9, 2017 article in Science. The study is believed to be the first report of a particular type of Einstein’s “gravitational microlensing” by a star other than the sun.

In a related perspective piece in Science, entitled “A centennial gift from Einstein,” Terry Oswalt of Embry-Riddle Aeronautical University says the discovery opens a new window to understanding “the history and evolution of galaxies such as our own.”

More specifically, Oswalt adds, “The research by Sahu and colleagues provides a new tool for determining the masses of objects we can’t easily measure by other means. The team determined the mass of a collapsed stellar remnant called a white dwarf star. Such objects have completed their hydrogen-burning life cycle, and thus are the fossils of all prior generations of stars in our Galaxy, the Milky Way.”

Oswalt, an astronomer and chair of the Department of Physical Sciences at Embry-Riddle’s Daytona Beach, Florida campus, says further, “Einstein would be proud. One of his key predictions has passed a very rigorous observational test.”

Oswalt, an astronomer and chair of the Department of Physical Sciences at Embry-Riddle’s Daytona Beach, Florida campus, says further, “Einstein would be proud. One of his key predictions has passed a very rigorous observational test.”

Understanding ‘Einstein Rings’

The gravitational microlensing of stars, predicted by Einstein, has previously been observed. Famously, in 1919, measurements of starlight curving around a total eclipse of the Sun provided one of the first convincing proofs of Einstein’s general theory of relativity – a guiding law of physics that describes gravity as a geometric function of both space and time, or spacetime.

“When a star in the foreground passes exactly between us and a background star,” Oswalt explains, “ results in a perfectly circular ring of light – a so-called ‘Einstein ring.'”

New confirmation of Einstein's General Theory of Relativity
Astronomers made the Hubble observations of the white dwarf, the burned-out core of a normal star, and the faint background star over a two-year period. Hubble observed the dead star passing in front of the background star, deflecting its …more

Sahu’s group observed a much more likely scenario: Two objects were slightly out of alignment, and therefore an asymmetrical version of an Einstein ring formed. “The ring and its brightening were too small to be measured, but its asymmetry caused the distant star to appear off-center from its true position,” Oswalt says. “This part of Einstein’s prediction is called ‘astrometric lensing’ and Sahu’s team was the first to observe it in a star other than the Sun.”

Sahu, an astronomer at the Space Telescope Science Institute in Baltimore, Maryland, took advantage of the superior angular resolution of the Hubble Space Telescope (HST). Sahu’s team measured shifts in the apparent position of a as its light was deflected around a nearby white dwarf star called Stein 2051 B on eight dates between October 2013 and October 2015. They determined that Stein 2051 B – the sixth-closest to the Sun – has a mass that is about two-thirds that of the sun.

“The basic idea is that the apparent deflection of the background star’s position is directly related to the mass and gravity of the white dwarf – and how close the two came to exactly lining up,” explains Oswalt.

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Sept. 26: NASA Sets to Release Details of ‘Surprising Activity’ on Europa, Many Speculate Alien Life

europa-compressed

By Amando Flavio | We Are Anonymous

The rumors about alien life have once again appeared. This time, the rumors were started by an announcement made by the United States National Aeronautics and Space Administration (NASA).

According to NASA, it will hold a teleconference on Monday, Sept. 26, 2016, to present new findings from images of Europa, one of the largest of Jupiter’s 67 known moons, captured by the Hubble Space Telescope. Europa is said to be the sixth-closest moon of Jupiter, and the smallest of its four Galilean satellites, as well as the sixth-largest moon in the solar system. Its distance to Earth is approximately 628.3 million km.

Related Article: NASA Astronaut Scott Kelly ADMITS the Existence of ALIENS – After His Year In Space

NASA said in a statement: “Astronomers will present results from a unique Europa observing campaign that resulted in surprising evidence of activity that may be related to the presence of a subsurface ocean on Europa.”

NASA said participants in the teleconference will include: Paul Hertz, director of NASA’s Astrophysics Division; William Sparks of the Space Telescope Science Institute in Baltimore; Britney Schmidt of the Georgia Institute of Technology; and Jennifer Wiseman, senior Hubble project scientist at NASA’s Goddard Space Flight Center.

Immediately after NASA issued the statement, fevered speculations about alien life appeared on social media. The speculations emerged due to researchers in the past having said Europa is one of the best places to find alien life in the solar system. In fact, some astrobiologists have even theorized that organisms could survive in its oceans.

In late 2013, it is said the Hubble telescope observed water vapor erupting from Europa. Many researchers hailed the development as a ‘tremendously exciting’ discovery.

Even before the 2013 discovery, previous scientific findings on Europa had revealed existence of a possible ocean located under its icy crust. Researchers who made the discovery theorized then, that if the ice on the surface of the moon is drilled to the ground, oceans will be detected. This discovery on Europa fueled the debate about the possibility of alien life. Lorenz Roth of Southwest Research Institute in San Antonio said at the time, that if the plumes of vapor were connected to the ocean beneath the crust, they could start searching for life nearer the surface.

The Telegraph quoted him as saying: “This means that future investigations can directly investigate the chemical makeup of Europa’s potentially habitable environment without drilling through layers of ice. And that is tremendously exciting.”

In this current announcement by NASA, when speculations about a possible alien life on Europa began trending on social media, NASA tweeted to quash the rumors.

Extraterrestrial life, commonly referred to as alien life, is a life that does not originate from the Earth. Some cosmologists believe alien life ranges from simple bacteria-like organisms to civilizations that are far more advanced than that of human beings.

Some exobiologists also suspect that alien life exists, although there is no empirical evidence to prove it. Exobiology is the knowledge and study of alien life.

NASA

Since the mid-20th century, there has been a significant surge in the search for signs of alien intelligence by researchers. Radios have been deployed to detect possible extraterrestrial signals and telescopes have also been mounted to search for potentially habitable extra solar planets.

Related Article: Stephen Hawking Just Issued a Chilling Warning to Scientists Searching for Alien Life

Many science fiction movies on alien life have also been released to the public. This has increased the public interest in the search for alien life, especially among the western public. Some researchers encourage aggressive methods to try and contact alien life, however, some also believe that contacting aliens will be dangerous for humanity.

NASA

Particularly this year, a possible detection of alien life, or planets occupied by aliens, has appeared many times in the media.

In August 2016, the German investigative weekly news magazine, Der Spiegel, revealed that researchers at the European Southern Observatory (ESO) have discovered a new Earth-like planet with water. Several attempts by journalists to have the ESO confirm or deny the report by Der Spiegel,proved futile, prompting some conspiracy theorists to say the organization has discovered a planet inhabited by aliens, and is hiding it from the public.

NASA

Recently also, Russian astronomers engaged in the Search of Extraterrestrial Intelligence, detected a strong mysterious radio signal on a sun-like star, around 94 light years from Earth. Light years is a unit of length used informally to express astronomical distances. One light year is approximately 9 trillion kilometres. According to the Russian researchers, the strange signal was detected from the direction of HD164595. This revelation sparked alien life speculation.

Stay with us for the latest on what NASA has discovered on Europa. We are following the event closely.


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Today Is 25th Anniversary of Hubble’s First Photo: Video Shows How Far We’ve Come

Source: Newsy Science

Transcript:
The Hubble Space Telescope is known for its dazzling images of cosmic phenomena, but it didn’t exactly start that way.

Its first ever image, captured 25 years ago today, is decidedly less exciting. This is HD96755, a part of star cluster NGC 3532, about 1,300 light years away. It underwhelmed people back then, too.

After its launch, the Hubble Space Telescope had an attached PR campaign touting it as a scientific improvement over ground-based telescopes of the time. (Video via ESA/Hubble)

David Leckrone was Hubble’s senior project scientist until 2009. As he told Time, expectations were high. Reality was still kind of blurry. (Video via C-SPAN)

“The astronomers groaned when the media was invited. And everyone was a little perplexed and uncomfortable when the image came in because it was so out of focus. Someone said ‘Is that the way it’s supposed to look?’”

No, it wasn’t. This image came before any calibration or fine-tuning of Hubble’s instruments.

There was no post-processing, either. The images Hubble is known for go through an extensive cleanup and color-assignment process to get as good-looking as they are. (Video via the Space Telescope Science Institute)

That shot of HD96755 was what’s known as a “first light test.” It’s more to certify the cameras and mirrors are all working than to show off what they’re capable of.

Of course, it didn’t help that Hubble’s primary mirror was also flawed.

The first maintenance mission to Hubble, flown by the Space Shuttle Columbia in December 1993, delivered specialized hardware to correct the mirror and sharpen the images it captured.

Over the next months, astronomers dialed in their process and started turning out images Hubble is much better known for.

And to this day, Hubble is still at it. NASA says the telescope will keep collecting images for as long as it stays in working condition. (Video via NASA)

This video includes images from NASA and RadioFan / CC BY SA 3.0.




Hubble Telescope Captures Spectacular New Views of ‘Pillars of Creation’

Nola Taylor Redd |  Livescience


SEATTLE — A famous deep-space object imaged by the Hubble Space Telescope 20 years ago has been reborn in an amazing new photo.

Scientists pointed the telescope at the iconic Eagle Nebula, also known as Messier 16 (M16), capturing the famous “Pillars of Creation” in sharper and wider view. The new and improved image was possible thanks to upgrades made to the Hubble Space Telescope over the past 25 years. You can see the new Pillars of Creation image in detail in a breathtaking new video of the Hubble views as well.

“It allows us to demonstrate how far Hubble has come in 25 years of observation,” Paul Scowen, of Arizona State University, said during a news conference here at the 225th meeting of the American Astronomical Society Monday (Jan. 5). Scowen was one of the astronomers who helped take the original iconic image. [See more amazing images from Hubble]

The Hubble Space Telescope has taken a fresh look at the iconic Pillars of Creation in the Eagle Nebula 6,500 light-years from Earth, revealing the most detailed view yet of a feature Hubble originally discovered 20 years ago. The new image was taken to commemorate Hubble's 25th anniversary in 2015.  Credit: ASA, ESA/Hubble and the Hubble Heritage

The Hubble Space Telescope has taken a fresh look at the iconic Pillars of Creation in the Eagle Nebula 6,500 light-years from Earth, revealing the most detailed view yet of a feature Hubble originally discovered 20 years ago. The new image was taken to commemorate Hubble’s 25th anniversary in 2015.
Credit: ASA, ESA/Hubble and the Hubble Heritage

Dubbed the “Pillars of Creation” when it was discovered in 1995, the Eagle Nebula view is arguably the most famous of all of Hubble’s images. It has appeared on postage stamps, T-shirts and pillows, and even made the rounds in television shows and movies. Located approximately 7,000 light-years from the sun, M16 is a region of gas and dust where stars form at a rapid clip.

The new Hubble image utilizes the Wide Field Camera 3, installed in 2009, to reveal the star-forming region at twice the resolution of the original instrument. As with the original image, taken by the Wide Field and Planetary Camera 2, elements in the image appear as different colors: Red reveals singly ionized sulfur, blue shows double-ionized oxygen and green highlights hydrogen.

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