The Dwarf Planet is officially the Largest in Solar System

This image shows an artist impression of the Dwarf Planet Eris.

Since Eris is larger than the Dwarf Planet Pluto, it is presented as the tenth planet.

However, a long-lasting debate over the status of Pluto forced the International Astronomical Union (IAU) to develop a precise definition of the term planet. 

On August 24, 2006, the IAU adopted a resolution, under which both Pluto and Eris were classified as "dwarf planets" and subsequently added to the Minor Planet Catalogue.

Our universe is full of mysteries but there are a few things we know for certain.

For instance, that the Earth orbits the Sun and not vice versa, or that there are eight planets in the solar system. If you still believe in the latter, you probably have not heard of Eris.

This is an image of the dwarf planet Eris (center) and its companion satellite Dysnomia (at 9 o'clock position) taken with NASA's Hubble Space Telescope on Aug. 30, 2006. Hubble observations were obtained on Dec. 3, 2005 and Aug. 30, 2006 using the Advanced Camera for Surveys.

Credit: Hubblesite

Eris is the largest dwarf planet discovered in 2005 using the Hubble Telescope and was initially described by NASA as the Solar System's tenth planet.

Eris is 27% larger than Pluto, has a diameter of 2.3 kilometers and one companion satellite (moon) called Dysnomia.

The planet orbits the sun at a distance of 96.4 astronomical units, taking 557 years to complete one lap.

Whilst it sounds like a fully-fledged planet, the word 'dwarf' tends to instill confusion. Eris is what astronomers call a plutoid; a trans-Neptunian object located in the part of the solar system known as the Kuiper belt.

A dwarf planet is now officially defined as a "celestial body in direct orbit of the Sun that is massive enough for its shape to be controlled by gravity, but that unlike a planet has not cleared its orbit of other objects."

The number of known planets in the solar system was therefore reduced to eight, as it was before Pluto's discovery in 1930.

With the new status Eris was granted its present name. Previously, the newly discovered space object was informally called Xena after a character from the popular television series Xena: Warrior Princess, but given the discord it caused in the astronomical community, the name of the Greek goddess Eris, a personification of strife, suits this planet like no other.

NASA ESA Hubble Sees a Spiral in Fornax (Furnace)

This Hubble image is a snapshot of NGC 986, a barred spiral galaxy discovered in 1828 by James Dunlop. 

This close-up view of the galaxy was captured by Hubble’s Wide Field and Planetary Camera 2 (WFPC2).

NGC 986 is found in the constellation of Fornax (The Furnace), located in the southern sky. 

NGC 986 is a bright, 11th-magnitude galaxy sitting around 56 million light-years away, and its golden center and barred swirling arms are clearly visible in this image.

Barred spiral galaxies are spiral galaxies with a central bar-shaped structure composed of stars. NGC 986 has the characteristic S-shaped structure of this type of galactic morphology. 

Young blue stars can be seen dotted amongst the galaxy’s arms and the core of the galaxy is also aglow with star formation.

To the top right of this image the stars appear a little fuzzy. This is because a gap in the Hubble data was filled in with data from ground-based telescopes. 

Although the view we see in this filled in patch is accurate, the resolution of the stars is no match for Hubble’s clear depiction of the spiral galaxy.

Credit: NASA/ESA

Hubble image: Galaxy Cluster Abell 1413 Between the Lion and Berenice's Hair

Galaxy cluster Abell 1413 lies between the constellations of Leo (The Lion) and Coma Berenices (Berenice's Hair), at a distance of over 2 billion light-years from Earth. 

A large, very elliptical galaxy called MCG+04-28-097 shines at the center of this image, with a halo of stars extending outward more than 6.5 million light-years.

Abell 1413 contains more than 300 galaxies bound together by the immense gravity of the cluster.

Abell 1413 is part of the Abell catalogue, a collection of over 4000 rich clusters of galaxies fairly close to Earth, at least from a cosmological perspective, their light took less than 3 billion years to reach us.

The clusters are called rich due to the huge number of galaxies they play host to. Abell 1413 is observed to contain more than 300 galaxies held together by the immense gravity of the cluster.

The strong interactions between these galaxies cause the material in the cluster to be heated to extremely high temperatures of almost 100 million degrees, because of this, the cluster emits very strong X-ray radiation.

Visible distortions in the image can be seen in the form of arcs, caused by gravitational lensing.

Hubble views the hazy image of NGC1501 - The Oyster Nebula

Credit: ESA/Hubble & NASA; acknowledgement: Marc Canale

This image from Hubble's Wide Field Planetary Camera 2 (WFPC2) showcases NGC 1501, a complex planetary nebula located in the large but faint constellation of Camelopardalis (The Giraffe).

Discovered by William Herschel in 1787, NGC 1501 is a planetary nebula that is just under 5,000 light-years away from us.

Astronomers have modeled the three-dimensional structure of the nebula, finding it to be a cloud shaped as an irregular ellipsoid filled with bumpy and bubbly regions.

It has a bright central star that can be seen easily in this image, shining brightly from within the nebula's cloud.

This bright pearl embedded within its glowing shell inspired the nebula's popular nickname: the Oyster Nebula.

While NGC 1501's central star blasted off its outer shell long ago, it still remains very hot and luminous, although it is quite tricky for observers to spot through modest telescopes.

This star has actually been the subject of many studies by astronomers due to one very unusual feature: it seems to be pulsating, varying quite significantly in brightness over a typical timescale of just half an hour.

While variable stars are not unusual, it is uncommon to find one at the heart of a planetary nebula.

It is important to note that the colors in this image are arbitrary.

Hubble surveys debris-strewn exoplanetary construction yards

This is a set of images from a NASA Hubble Space Telescope survey of the architecture of debris systems around young stars. 

Ten previously discovered circumstellar debris systems, plus MP Mus (a mature protoplanetary disk of age comparable to the youngest of the debris disks), were studied. 

Hubble's sharp view uncovers an unexpected diversity and complexity in the structures. The disk-like structures are vast, many times larger than the planetary distribution in our solar system. 

Some disks are tilted edge-on to our view, others nearly face-on. 

Asymmetries and warping in the disks might be caused by the host star's passage though interstellar space. 

Alternatively, the disks may be affected by the action of unseen planets. In particular, the asymmetry in HD 181327 looks like a spray of material that is very distant from its host star. 

It might be the aftermath of a collision between two small bodies, suggesting that the unseen planetary system may be chaotic. 

The stars surveyed may be as young as 10 million years old and as mature as more than 1 billion years old. 

The visible-light survey was done with the Space Telescope Imaging Spectrograph (STIS). 

The STIS coronagraph blocks out the light from the host star so that the very faint reflected light from the dust structures can be seen. 

The images have been artificially coloured to enhance detail. 

Credit: NASA, ESA, G. Schneider (University of Arizona), and the HST/GO 12228 Team

Astronomers using NASA's Hubble Space Telescope have completed the largest and most sensitive visible-light imaging survey of dusty debris disks around other stars.

These dusty disks, likely created by collisions between leftover objects from planet formation, were imaged around stars as young as 10 million years old and as mature as more than 1 billion years old.

"It's like looking back in time to see the kinds of destructive events that once routinely happened in our solar system after the planets formed," said survey leader Glenn Schneider of the University of Arizona's Steward Observatory.

The survey's results appeared in the Oct. 1, 2014, issue of The Astronomical Journal.

Once thought to be simply pancake-like structures, the unexpected diversity and complexity of these dusty debris structures strongly suggest they are being gravitationally affected by unseen planets orbiting the star.

Alternatively, these effects could result from the stars' passing through interstellar space.

The researchers discovered that no two "disks" of material surrounding stars look the same. "We find that the systems are not simply flat with uniform surfaces," Schneider said.

"These are actually pretty complicated three-dimensional debris systems, often with embedded smaller structures. Some of the substructures could be signposts of unseen planets."

The astronomers used Hubble's Space Telescope Imaging Spectrograph (STIS) to study 10 previously discovered circumstellar debris systems, plus MP Mus, a mature protoplanetary disk of age comparable to the youngest of the debris disks.

Irregularities observed in one ring-like system in particular, around a star called HD 181327, resemble the ejection of a huge spray of debris into the outer part of the system from the recent collision of two bodies.

"This spray of material is fairly distant from its host star, roughly twice the distance that Pluto is from the Sun," said co-investigator Christopher Stark of NASA's Goddard Space Flight Center, Greenbelt, Maryland.

"Catastrophically destroying an object that massive at such a large distance is difficult to explain, and it should be very rare."

"If we are in fact seeing the recent aftermath of a massive collision, the unseen planetary system may be quite chaotic."

Another interpretation for the irregularities is that the disk has been mysteriously warped by the star's passage through interstellar space, directly interacting with unseen interstellar material. "Either way, the answer is exciting," Schneider said.

"Our team is currently analyzing follow-up observations that will help reveal the true cause of the irregularity."

More information: "Probing for Exoplanets Hiding in Dusty Debris Disks: Disk Imaging, Characterization, and Exploration with HST/STIS Multi-Roll Coronagraphy," Glenn Schneider et al., 2014, Astronomical Journal, Vol. 148, No. 4, Art. 59 dx.doi.org/10.1088/0004-6256/148/4/59 , On Arxiv: arxiv.org/abs/1406.7303

Hubble observes Jets, bubbles, and bursts of light in Taurus

The NASA/ESA Hubble Space Telescope has snapped a striking view of a multiple star system called XZ Tauri, its neighbour HL Tauri and several nearby young stellar objects. 

XZ Tauri is blowing a hot bubble of gas into the surrounding space, which is filled with bright and beautiful clumps that are emitting strong winds and jets. 

These objects illuminate the region, creating a truly dramatic scene. 

Credit: ESA/Hubble/ NASA

The NASA/ESA Hubble Space Telescope has snapped a striking view of a multiple star system called XZ Tauri, its neighbour HL Tauri, and several nearby young stellar objects.

XZ Tauri is blowing a hot bubble of gas into the surrounding space, which is filled with bright and beautiful clumps that are emitting strong winds and jets.

These objects illuminate the region, creating a truly dramatic scene.

This dark and ominous landscape is located some 450 light-years away in the constellation of Taurus (The Bull).

It lies in the north-eastern part of a large, dark cloud known as LDN 1551.

Just to the left of centre in this image, embedded within a rust-coloured cloud, lies XZ Tauri. While it appears to be a single star, this bright spot actually consists of several stars.

It has long been known to be a binary, but one of these two stars is thought also to be a binary, making a total of three stars within a single system.

This is not the first time that Hubble has observed XZ Tauri, between the years of 1995 and 2000, a hot bubble of gas was spotted expanding outwards from the system.

This bubble can be seen as the small orange lobe very close to the top left of XZ Tauri. This gas is speeding out from the star system, leaving a trail spanning tens of billions of kilometres.

As the bubble travels it hits slower moving material, triggering pulses of light and rippling shockwaves.

Above and to the right of XZ Tauri, an equally epic scene is unfolding. Wisps of deep red seem to be streaking away from the blue-tinged clumps on the right.

This bright blue patch contains a star known as HL Tauri, which is associated with Herbig-Haro object HH 150.

Herbig-Haro objects are streaks of hot gas blasted into space by newborn and newly forming stars and LDN 1551 is particularly rich in these dramatic objects.

In the bottom right of this Hubble image is another Herbig-Haro object known as HH 30, associated with the variable star V1213 Tauri.

The star itself is hidden within a flat, bright disc of dust that is split in half by a dark lane. This dust blocks direct light from V1213 Tauri, but the star is visible via its reflected light and the prominent, knotty jets it is blasting out into space.

Hubble previously viewed HH 30, alongside XZ Tauri, with its Wide Field Planetary Camera 2 between the years of 1995 and 2000.

The observations were used to image and study the changes in disc brightness and jet strength over the five-year period.

V1213 Tauri's strong magnetic field forms the jets by funnelling and shepherding gas from the disc, accelerating it along the star's magnetic poles to form two narrow beams.

ALMA image of the young star HL Tau and its protoplanetary disk. 

This best image ever of planet formation reveals multiple rings and gaps that herald the presence of emerging planets as they sweep their orbits clear of dust and gas 

Credit: ALMA (NRAO /ESO /NAOJ); C. Brogan, B. Saxton (NRAO /AUI /NSF)

In the above image released by the European Southern Observatory today, observations from the Atacama Large Millimeter /submillimeter Array (ALMA) reveal extraordinarily fine and never-before-seen detail in the planet-forming disc around HL Tauri.

The new observations are an enormous step forward in the observation of how protoplanetary discs develop and how planets form.

Standard Model may account for Dark Matter and it may be massive

A massive cluster of yellowish galaxies, seemingly caught in a red and blue spider web of eerily distorted background galaxies, makes for a spellbinding picture from the new Advanced Camera for Surveys (ACS) aboard NASA's Hubble Space Telescope. 

To make this unprecedented image of the cosmos, Hubble peered straight through the center of one of the most massive galaxy clusters known, called Abell 1689. 

The gravity of the cluster's trillion stars, plus dark matter, acts as a 2-million-light-year-wide lens in space. 

This gravitational lens bends and magnifies the light of the galaxies located far behind it. Some of the faintest objects in the picture are probably over 13 billion light-years away (redshift value 6). 

Strong gravitational lensing as observed by the Hubble Space Telescope in Abell 1689 indicates the presence of dark matter. 

Credit: NASA, N. Benitez (JHU), T. Broadhurst (Racah Institute of Physics/The Hebrew University), H. Ford (JHU), M. Clampin (STScI),G. Hartig (STScI), G. Illingworth (UCO/Lick Observatory), the ACS Science Team and ESA

The physics community has spent three decades searching for and finding no evidence that dark matter is made of tiny exotic particles.

Case Western Reserve University theoretical physicists suggest researchers consider looking for candidates more in the ordinary realm and, well, more massive.

Dark matter is unseen matter, that, combined with normal matter, could create the gravity that, among other things, prevents spinning galaxies from flying apart.

Physicists calculate that dark matter comprises 27 percent of the universe; normal matter 5 percent.

Instead of WIMPS, weakly interacting massive particles, or axions, which are weakly interacting low-mass particles, dark matter may be made of macroscopic objects, anywhere from a few ounces to the size of a good asteroid, and probably as dense as a neutron star, or the nucleus of an atom, the researchers suggest.

Physics professor Glenn Starkman and David Jacobs, who received his PhD in Physics from CWRU in May and is now a fellow at the University of Cape Town, say published observations provide guidance, limiting where to look.

They lay out the possibilities in a paper "Macro Dark Matter"

The Macros, as Starkman and Jacobs call them, would not only dwarf WIMPS and axions, but differ in an important way.

They could potentially be assembled out of particles in the Standard Model of particle physics instead of requiring new physics to explain their existence.

"We've been looking for WIMPs for a long time and haven't seen them," Starkman said. "We expected to make WIMPS in the Large Hadron Collider (LHC), and we haven't."

WIMPS and axions remain possible candidates for dark matter, but there's reason to search elsewhere, the theorists argue.

"The community had kind of turned away from the idea that dark matter could be made of normal-ish stuff in the late '80s," Starkman said.

"We ask, was that completely correct and how do we know dark matter isn't more ordinary stuff— stuff that could be made from quarks and electrons?"

After eliminating most ordinary matter, including failed Jupiters, white dwarfs, neutron stars, stellar black holes, the black holes in centers of galaxies and neutrinos with a lot of mass, as possible candidates, physicists turned their focus on the exotics.

Hubble sees 'ghost light' from dead galaxies

Massive galaxy cluster Abell 2744, nicknamed Pandora's Cluster, takes on a ghostly look where total starlight has been artificially colored blue in this Hubble view. 

Credit: NASA/ESA/IAC/HFF Team, STScI

NASA's Hubble Space Telescope has picked up the faint, ghostly glow of stars ejected from ancient galaxies that were gravitationally ripped apart several billion years ago.

The mayhem happened 4 billion light-years away, inside an immense collection of nearly 500 galaxies nicknamed "Pandora's Cluster," also known as Abell 2744.

The scattered stars are no longer bound to any one galaxy, and drift freely between galaxies in the cluster.

By observing the light from the orphaned stars, Hubble astronomers have assembled forensic evidence that suggests as many as six galaxies were torn to pieces inside the cluster over a stretch of 6 billion years.

Computer modeling of the gravitational dynamics among galaxies in a cluster suggests that galaxies as big as our Milky Way Galaxy are the likely candidates as the source of the stars.

The doomed galaxies would have been pulled apart like taffy if they plunged through the center of a galaxy cluster where gravitational tidal forces are strongest.

Astronomers have long hypothesized that the light from scattered stars should be detectable after such galaxies are disassembled.

However, the predicted "intracluster" glow of stars is very faint and was therefore a challenge to identify.

"The Hubble data revealing the ghost light are important steps forward in understanding the evolution of galaxy clusters," said Ignacio Trujillo of The Instituto de Astrofísica de Canarias (IAC), Santa Cruz de Tenerife, Spain.

"It is also amazingly beautiful in that we found the telltale glow by utilizing Hubble's unique capabilities."

The team estimates that the combined light of about 200 billion outcast stars contributes approximately 10 percent of the cluster's brightness.

"The results are in good agreement with what has been predicted to happen inside massive galaxy clusters," said Mireia Montes of the IAC, lead author of the paper published in the Oct. 1 issue of the Astrophysical Journal.

Because these extremely faint stars are brightest at near-infrared wavelengths of light, the team emphasized that this type of observation could only be accomplished with Hubble's infrared sensitivity to extraordinarily dim light.

Hubble measurements determined that the phantom stars are rich in heavier elements like oxygen, carbon, and nitrogen.

This means the scattered stars must be second or third-generation stars enriched with the elements forged in the hearts of the universe's first-generation stars.

Spiral galaxies, like the ones believed to be torn apart, can sustain ongoing star formation that creates chemically-enriched stars.

Weighing more than 4 trillion solar masses, Abell 2744 is a target in the Frontier Fields program.

This ambitious three-year effort teams Hubble and NASA's other Great Observatories to look at select massive galaxy clusters to help astronomers probe the remote universe.

Galaxy clusters are so massive that their gravity deflects light passing through them, magnifying, brightening, and distorting light in a phenomenon called gravitational lensing.

Astronomers exploit this property of space to use the clusters as a zoom lens to magnify the images of far-more-distant galaxies that otherwise would be too faint to be seen.

Montes' team used the Hubble data to probe the environment of the foreground cluster itself. There are five other Frontier Fields clusters in the program, and the team plans to look for the eerie "ghost light" in these clusters, too.

More information: "Intracluster Light at the Frontier: A2744," Mireia Montes and Ignacio Trujillo, 2014, Astrophysical Journal, Vol. 794, No. 2, Art. 137 dx.doi.org/10.1088/0004-637X/794/2/137, On Arxiv: arxiv.org/abs/1405.2070

Supernova iPTF13bvn: First evidence of a hydrogen-deficient supernova progenitor

An artist’s conception of a binary progenitor system of the supernova iPTF13bvn. 

Larger diameter but smaller mass (4 times mass of the Sun) helium star shown on the left is to explode. 

The companion star shown on the right is a hydrogen rich star and 30 times mass of the Sun. 

Credit: Kavli Institute for the Physics and Mathematics of the Universe

A group of researchers led by Melina Bersten of Kavli IPMU recently presented a model that provides the first characterization of the progenitor for a hydrogen-deficient supernova.

Their model predicts that a bright hot star, which is the binary companion to an exploding object, remains after the explosion.

To verify their theory, the group secured observation time with the Hubble Space Telescope (HST) to search for such a remaining star.

Their findings, which are reported in the October 2014 issue of The Astronomical Journal, have important implications for the evolution of massive stars.

For years astronomers have searched for the elusive progenitors of hydrogen-deficient stellar explosions without success.

However, this changed in June 2013 with the appearance of supernova iPTF13bvn and the subsequent detection of an object at the same location in archival images obtained before the explosion using the HST.

The interpretation of the observed object is controversial. The team led by Bersten presented a self-consistent picture using models of supernova brightness and progenitor evolution.

In their picture, the more massive star in a binary system explodes after transferring mass to its companion.

One of the challenges in astrophysics is identifying which star produces which supernova. This is particularly problematic for supernovae without hydrogen, which are called Types Ib or Ic, because the progenitors have yet to be detected directly.

However, the ultimate question is: "How do progenitor stars remove their hydrogen-rich envelopes during their evolution?"

Two competing mechanisms have been proposed. One hypothesizes that a strong wind produced by a very massive star blows the outer hydrogen layers, while the other suggests that a gravitationally bound binary companion star removes the outer layers.

The latter case does not require a very massive star. Because these two scenarios predict vastly different progenitor stars, direct detection of the progenitor for this type of supernova can provide definitive clues about the preferred evolutionary path.

When young Type Ib supernova iPTF13bvn was discovered in nearby spiral galaxy NGC 5806, astronomers hoped to find its progenitor.

Inspecting the available HST images did indeed reveal an object, providing optimism that the first hydrogen-free supernova progenitor would at last be identified.

Due to the object's blue hue, it was initially suggested that the object was a very hot, very massive, evolved star with a compact structure, called a "Wolf-Rayet" star.

NB: Using models of such stars, a group based in Geneva was able to reproduce the brightness and color of the pre-explosion object with a Wolf-Rayet star that was born with over 30 times the mass of the Sun and died with 11 times the solar mass.

Supernova iPTF13bvn discovered in nearby spiral galaxy NGC 5806. 

Credit: Jean Marie Llapasset

"Based on such suggestions, we decided to check if such a massive star is consistent with the supernova brightness evolution," says Melina Bersten.

However, the results are inconsistent with a Wolf-Rayet star; the exploding star must have been merely four times the mass of the Sun, which is much smaller than a Wolf-Rayet star.

"If the mass was this low and the supernova lacked hydrogen, our immediate conclusion is that the progenitor was part of a binary system," adds Bersten.

More information: The Astronomical Journal, 148:68 (6pp), 2014 October. DOI: 10.1088/0004-6256/148/4/68

Male Hubble teams getting more telescope time

Researchers at the Space Telescope Science Institute (STScI) which runs the Hubble Space Telescope program, have found that there continues to be a gap between the number of projects given the go-ahead by male principle investigators (PIs) versus those headed by females.

Principle Investigators (PIs) are typically listed as the lead on proposals and when they are male, the researchers report, the chances are greater that their project will be approved.

In their paper uploaded to the preprint server arXiv (soon to be published in Publications of the Astronomical Society of the Pacific) the researchers note that efforts have been made to get rid of gender bias, but there still appears to be room for improvement.

It's not easy getting time on Hubble, researchers must form teams and then come up with something relevant and interesting to study.

After that, they have to write a proposal and submit it to STScI, after review the proposal is accepted or rejected, only a quarter of those submitted wind up getting telescope time.

Unfortunately, it seems that the odds are diminished even further if the PI is female. Not by much, the researchers report, just by four or five projects each proposal cycle, but that's enough to cause concern, especially in light of the fact that program officials have been trying to eliminate such perceived bias.

They've tried giving talks to reviewers, to explain the problem in the hopes it will cause them to be less biased, they've tried moving team members name to the back page, and even using just an initial for the first name of the PI. None of its worked, and the researchers don't know why.

They acknowledge that it's possible that female led proposals are simply not as interesting or as well thought out or written, in some cases, but also point out that very few if any proposals are written by only female teams, they're all filled with both men and women. Gender appears to only play a role for the PI.

The researchers have been studying the problem for two years, and are still mystified by the lack of change, they note that the problem is more pronounced when the PI is more senior, the difference is smaller for recent graduates, suggesting that the problem may solve itself given time.

They also note that Hubble isn't the only program with the problem, some small studies have suggested that female led proposals meet with less success on other observatories as well.

More information: Full paper: arxiv.org/abs/1409.3528

NASA/ESA Hubble Space Telescope image of the Antennae Galaxies

The NASA/ESA Hubble Space Telescope image of the Antennae Galaxies.

The galaxies, also known as NGC 4038 and NGC 4039, are locked in a deadly embrace. 

Once normal, sedate spiral galaxies like the Milky Way, the pair have spent the past few hundred million years sparring with one another. 

This clash is so violent that stars have been ripped from their host galaxies to form a streaming arc between the two. 

Credit: ESA/Hubble & NASA

Fascinating rhythm: Light pulses illuminate a rare black hole in Messier 82

This image of the galaxy Messier 82 is a composite of data from the Chandra X-Ray Observatory, the Hubble Space Telescope and the Spitzer Space Telescope. 

The intermediate-mass black hole M82 X-1 is the brightest object in the inset, at approximately 2 o'clock near the galaxy's center. 

Credit: NASA/H. Feng et al.

The universe has so many black holes that it's impossible to count them all. There may be 100 million of these intriguing astral objects in our galaxy alone.

Nearly all black holes fall into one of two classes: big, and colossal. Astronomers know that black holes ranging from about 10 times to 100 times the mass of our sun are the remnants of dying stars, and that supermassive black holes, more than a million times the mass of the sun, inhabit the centers of most galaxies.

But scattered across the universe like oases in a desert are a few apparent black holes of a more mysterious type.

Ranging from a hundred times to a few hundred thousand times the sun's mass, these intermediate-mass black holes are so hard to measure that even their existence is sometimes disputed.

Little is known about how they form. And some astronomers question whether they behave like other black holes.

Now a team of astronomers has accurately measured, and thus confirmed the existence of, a black hole about 400 times the mass of our sun in a galaxy 12 million light years from Earth.

The finding, by University of Maryland astronomy graduate student Dheeraj Pasham and two colleagues, was published online August 17 in the journal Nature.

Co-author Richard Mushotzky, a UMD astronomy professor, says the black hole in question is a just-right-sized version of this class of astral objects.

"Objects in this range are the least expected of all black holes," says Mushotzky.

"Astronomers have been asking, do these objects exist or do they not exist? What are their properties? Until now we have not had the data to answer these questions."

"While the intermediate-mass black hole that the team studied is not the first one measured, it is the first one so precisely measured, Mushotzky says, "establishing it as a compelling example of this class of black holes."

Rossi satellite telescope

Between 2004 and 2010 NASA's Rossi X-Ray Timing Explorer (RXTE) satellite telescope observed M82 X-1 about 800 times, recording individual x-ray particles emitted by the object.

Pasham mapped the intensity and wavelength of x-rays in each sequence, then stitched the sequences together and analyzed the result.

Among the material circling the suspected black hole, he spotted two repeating flares of light. The flares showed a rhythmic pattern of light pulses, one occurring 5.1 times per second and the other 3.3 times per second – or a ratio of 3:2.

The two light oscillations were like two dust motes stuck in the grooves of a vinyl record spinning on a turntable, says Mushotzky.

Pasham used the oscillations to estimate that M82 X-1 is 428 times the mass of the sun, give or take 105 solar masses.

He does not propose an explanation for how this class of black holes formed. "We needed to confirm their existence observationally first," he says. "Now the theorists can get to work."

Neutron Star Interior Composition Explorer (NICER)

Though the Rossi telescope is no longer operational, NASA plans to launch a new X-ray telescope, the Neutron Star Interior Composition Explorer (NICER), in about two years.

Pasham, who will begin a post-doctoral research position at NASA Goddard in late August, has identified six potential intermediate-mass black holes that NICER might explore.

More information: "A 400 solar mass black hole in the M82 galaxy," Dheeraj R. Pasham, Tod E. Strohmayer, Richard F. Mushotzky, was published online Aug. 17, 2014 in Nature. dx.doi.org/10.1038/nature13710

NASA’s Hubble Finds Supernova Star System Linked to Potential “Zombie Star”

The two inset images show before-and-after images captured by NASA’s Hubble Space Telescope of Supernova 2012Z in the spiral galaxy NGC 1309. 

The white X at the top of the main image marks the location of the supernova in the galaxy.

Image Credit: NASA, ESA

Using NASA’s Hubble Space Telescope, a team of astronomers has spotted a star system that could have left behind a “zombie star” after an unusually weak supernova explosion.

A supernova typically obliterates the exploding white dwarf, or dying star.

On this occasion, scientists believe this faint supernova may have left behind a surviving portion of the dwarf star, a sort of zombie star.

While examining Hubble images taken years before the stellar explosion, astronomers identified a blue companion star feeding energy to a white dwarf, a process that ignited a nuclear reaction and released this weak supernova blast.

This supernova, Type Iax, is less common than its brighter cousin, Type Ia. Astronomers have identified more than 30 of these mini-supernovas that may leave behind a surviving white dwarf.

“Astronomers have been searching for decades for the star systems that produce Type Ia supernova explosions,” said scientist Saurabh Jha of Rutgers University in Piscataway, New Jersey.

“Type Ia’s are important because they’re used to measure vast cosmic distances and the expansion of the universe. But we have very few constraints on how any white dwarf explodes."

"The similarities between Type Iax’s and normal Type Ia’s make understanding Type Iax progenitors important, especially because no Type Ia progenitor has been conclusively identified. This discovery shows us one way that you can get a white dwarf explosion.”

The team’s results will appear in the Thursday, Aug. 7 edition of the journal Nature.

The weak supernova, dubbed SN 2012Z, resides in the host galaxy NGC 1309 which is 110 million light-years away. It was discovered in the Lick Observatory Supernova Search in January 2012.

Luckily, Hubble’s Advanced Camera for Surveys also observed NGC 1309 for several years prior the supernova outburst, which allowed scientists to compare before-and-after images.

Curtis McCully, a graduate student at Rutgers and lead author of the team’s paper, sharpened the Hubble pre-explosion images and noticed a peculiar object near the location of the supernova.

“I was very surprised to see anything at the location of the supernova. We expected the progenitor system would be too faint to see, like in previous searches for normal Type Ia supernova progenitors. It is exciting when nature surprises us,” McCully said.

After studying the object’s colors and comparing with computer simulations of possible Type Iax progenitor systems, the team concluded they were seeing the light of a star that had lost its outer hydrogen envelope, revealing its helium core.

The team plans to use Hubble again in 2015 to observe the area, giving time for the supernova’s light to dim enough to reveal any possible zombie star and helium companion to confirm their hypothesis.

“Back in 2009, when we were just starting to understand this class, we predicted these supernovae were produced by a white dwarf and helium star binary system,” said team member Ryan Foley of the University of Illinois at Urbana-Champaign, who helped identify Type Iax supernovae as a new class.

“There’s still a little uncertainty in this study, but it is essentially validation of our claim.”

Read the full article here

Robo-AO laser: Laser-wielding robot probes exoplanet systems

The ultraviolet Robo-AO laser originating from the Palomar 1.5-meter Telescope dome. 

Although the laser is invisible to the human eye, it shows up in digital SLR cameras once their internal UV blocking filters are removed. 

The apparent colour of the laser beam is a result of the UV light leaking through the camera's red, green and blue pixel filters by slightly different amounts.

An international team, including Dr. Christoph Baranec of the University of Hawaii at Manoa's Institute for Astronomy, is using the world's first robotic laser adaptive optics system, Robo-AO, to explore thousands of exoplanet systems (planets around other stars) at resolutions approaching those of the Hubble Space Telescope.

The results, which shed light on the formation of exotic exoplanet systems and confirm hundreds of exoplanets, have just been published in the Astrophysical Journal.

The design and operation of the unprecedented instrument has just been published in the Astrophysical Journal Letters.

Laser adaptive optics systems are used by terrestrial telescopes to remove the image-blurring effects of Earth's turbulent atmosphere, thereby capturing much sharper images than are otherwise possible from the ground.

Baranec, Robo-AO's principal investigator and lead author of the Astrophysical Journal Letter, led the development of the innovative Robo-AO system on the Palomar 1.5-meter Telescope.

It is the world's first instrument that fully automates the complex and often inefficient operation of laser adaptive optics.

"We're using Robo-AO's extreme efficiency to survey in exquisite detail all of the candidate exoplanet host stars that have been discovered by NASA's Kepler mission," said Baranec.

"While Kepler has an unrivaled ability to discover exoplanets that pass between us and their host star, it comes at the price of reduced image quality, and that's where Robo-AO excels."


In fact, analysis of the first part of the Robo-AO/Kepler exoplanet host survey is already yielding surprising results.

Nicholas Law

"We're finding that "hot Jupiters," rare giant exoplanets in tight orbits, are almost three times more likely to be found in wide binary star systems than other exoplanets, shedding light on how these exotic objects formed," said Prof. Nicholas Law (University of North Carolina at Chapel Hill's College of Arts and Sciences), Robo-AO's project scientist and lead author on the Astrophysical Journal paper.

"Going further, Robo-AO's unique capabilities have allowed us to discover even rarer objects: binary star systems where each star has a Kepler-detected planetary system of its own.

These systems will be uniquely interesting for studies of how the planets formed, and for science fiction about what life would be like with another planetary system right next door," continued Law.

Indeed, the first Robo-AO survey, covering 715 Kepler candidate exoplanet hosts, is the single largest scientific adaptive optics survey ever.

That record won't stand for very long, as the Robo-AO team is extending the survey to image each and every of the 4,000 Kepler candidate exoplanet hosts, and is ready to observe exoplanet hosts from Kepler's new K2 mission as they are discovered.

The Robo-AO laser being used to probe exoplanet host stars in the Kepler field. Images of the stars on the Robo-AO science camera (inset) are the same size as a single Kepler pixel. Credit: Robo-AO Collaboration.

The key to Robo-AO's success is its efficiency, allowing it to observe hundreds more targets per night than conventional adaptive optics systems.

So far, the Robo-AO system has already been used to make over 13,000 observations. "The automation of laser adaptive optics has allowed us to tackle scientific questions that were unimaginable just a few years ago.

We can now observe tens of thousands of objects at Hubble-Space-Telescope-like resolution in short periods of time," Baranec said.

"Now that the technology has been proven, we're looking to bring it to the pristine skies of Maunakea, Hawaii, where it will be even more powerful."

More information: Christoph Baranec et al. "HIGH-EFFICIENCY AUTONOMOUS LASER ADAPTIVE OPTICS." The Astrophysical Journal Letters Volume 790 Number 1, 2014 ApJ 790 L8 DOI: 10.1088/2041-8205/790/1/L8

Nicholas M. Law et al. "ROBOTIC LASER ADAPTIVE OPTICS IMAGING OF 715 KEPLER EXOPLANET CANDIDATES USING ROBO-AO" The Astrophysical Journal Volume 791 Number 1. 2014 ApJ 791 35 DOI: 10.1088/0004-637X/791/1/35

LEGO Model of ESA NASA Hubble Space Telescope

Gabriel Russo's idea for a Hubble Space Telescope model could become a real LEGO toy set if fans vote.

Credit: GRusso /LEGO Ideas

The Hubble Space Telescope is an iconic spacecraft responsible for almost a quarter of a century of astronomical discoveries and stunning stellar images.

As such, it is due time for it to be immortalised as a Lego model.

At least that is the idea of Gabriel Russo, a Lego fan and admirer of the orbiting observatory, who designed a Lego brick version of the space telescope and uploaded it to the Danish toy company's social website, "LEGO Ideas."

And judging by the number of supporters Russo's Hubble has recruited to date, just over 6,300 at press time, he is far from the only person who thinks it is a good idea.

"A Lego model of this amazing piece of space engineering would come as a perfect homage to its 25th anniversary in 2015," Russo wrote as a part of his model's description on the website.

LEGO have also recently celebrated the anniversary of the Moon Landing in LEGO.

The build in the picture took around 2-3 weeks for building techniques.

The "Moon" was just a grey blanket made similar to the Luna ground.

This set will include the Brick-Built version of the "Eagle" also known as the "Luna Lander", Neil Armstrong with his unique printed face and a removable helmet and a clip on chrome gold visor, Buzz Aldrin also with his unique printed face and a removable helmet and a clip on chrome gold visor and last but not final...Michael Collins, Again with his unique printed face and a removable helmet and a clip on chrome gold visor.

Angus MacLane's character Wall-E produced by LEGO.

LEGO Ideas, which was previously known as CUUSOO, invites Lego fans to share their proposals for new brick-built models.

Other fans and the public can then cast their votes on the website for their favourite ideas.

The concepts that successfully attract 10,000 supporters are considered by the toy company for commercial distribution.

NASA's Chandra X-ray Observatory celebrates 15th anniversary

Credit: NASA/CXC/SAO

Fifteen years ago, NASA's Chandra X-ray Observatory was launched into space aboard the Space Shuttle Columbia.

Since its deployment on July 23, 1999, Chandra has helped revolutionize our understanding of the universe through its unrivaled X-ray vision.

Chandra, one of NASA's current "Great Observatories," along with the Hubble Space Telescope and Spitzer Space Telescope, is specially designed to detect X-ray emission from hot and energetic regions of the universe.

With its superb sensitivity and resolution, Chandra has observed objects ranging from the closest planets and comets to the most distant known quasars.

It has imaged the remains of exploded stars, or supernova remnants, observed the region around the supermassive black hole at the center of the Milky Way, and discovered black holes across the universe.

Chandra also has made a major advance in the study of dark matter by tracing the separation of dark matter from normal matter in collisions between galaxy clusters. It is also contributing to research on the nature of dark energy.

To celebrate Chandra's 15th anniversary, four new images of supernova remnants; the Crab Nebula, Tycho, G292.0+1.8, and 3C58 – are being released.

These supernova remnants are very hot and energetic and glow brightly in X-ray light, which allows Chandra to capture them in exquisite detail.

"Chandra changed the way we do astronomy. It showed that precision observation of the X-rays from cosmic sources is critical to understanding what is going on," said Paul Hertz, NASA's Astrophysics Division director in Washington.

"We're fortunate we've had 15 years, so far, to use Chandra to advance our understanding of stars, galaxies, black holes, dark energy, and the origin of the elements necessary for life."

Chandra orbits far above Earth's X-ray absorbing atmosphere at an altitude up to 139,000 km (86,500 mi), allowing for long observations unobscured by Earth's shadow.

When it was carried into space in 1999, it was the largest satellite ever launched by the shuttle.

"We are thrilled at how well Chandra continues to perform," said Belinda Wilkes, director of the Chandra X-ray Center (CXC) in Cambridge, Massachusetts.

"The science and operations teams work very hard to ensure that Chandra delivers its astounding results, just as it has for the past decade and a half."

"We are looking forward to more ground-breaking science over the next decade and beyond."

Originally called the Advanced X-ray Astrophysics Facility (AXAF), the telescope was first proposed to NASA in 1976.

Prior to its launch aboard the shuttle, the observatory was renamed in honour of the late Indian-American Nobel laureate, Subrahmanyan Chandrasekhar.

Known to the world as Chandra (which means "moon" or "luminous" in Sanskrit), he was widely regarded as one of the foremost astrophysicists of the 20th century.

"Chandra continues to be one of the most successful missions that NASA has ever flown as measured against any metric, cost, schedule, technical success and, most of all, scientific discoveries," said Martin Weisskopf, Chandra Project Scientist at the Marshall Space Flight Center in Huntsville, Ala.

"It has been a privilege to work on developing and maintaining this scientific powerhouse, and we look forward to many years to come."

NASA Hubble Space Telescope (HST) facing retirement

It's taken dazzling images of galaxies, stars, planets and other celestial sights, 38,000 in total.

Now beginning its 25th year orbiting Earth at 17,500 mph, the Hubble Space Telescope is getting near the end of its dazzling mission.

Continually upgraded and updated throughout its life, Hubble will now be left alone to slowly degrade and, eventually, drift back to Earth and burn-up in the atmosphere.

Fortunately, Hubble won't be the last space telescope. Far from it, Hubble's replacement, the James Webb Space Telescope (JWST) will launch in October 2018 and be a stunning 100x times more powerful.

It's developers say that it will be able see back in time to the the very edge of the universe.

Within the 844GB of data per month sent back to Earth, and 100 terabytes in all, have been some ground-breaking images of planets and remote galaxies that have laid bare the very essence of space and time.

Perhaps the most important observation was the Hubble Deep Field, a long-exposure image taken in 1995 that captured the light of 4,000 galaxies near The Plough stretching 12 billion years back into time.

Hubble is a time machine; it captures light that's travelled since the beginning of time, and presents us photographs of things as they were just after the Big Bang.

The Hubble Deep Field image is fitting indeed; Hubble is named after astronomer Edwin P. Hubble, who theorised in the 1920s that the universe is expanding.

Around 6,500 light-years away in the constellation of Taurus is the stunning Crab Nebula, also called M1. 

It's the remnants of a star than went supernova in the year 1054, an event recorded by astronomers in China, Japan and Korea as a new star in Taurus.

Taken back in 2008, this image is about 10 light years wide and shows what happens when a star explodes.

Hubble is able to pick-out the mysterious and incredibly intricate filaments of the explosion.

At the centre is the remnant of the supernova, a dense pulsar that rotates 30 times each second.

A violent, complex scene of colliding galaxy clusters

Colliding galaxy clusters MACS J0717+3745, more than 5 billion light-years from Earth. Background is Hubble Space Telescope image; blue is X-ray image from Chandra, and red is VLA radio image. 

Credit: Van Weeren, et al.; Bill Saxton, NRAO /AUI /NSF; NASA.

Astronomers using the Karl G. Jansky Very Large Array (VLA) and the Chandra X-Ray Observatory have produced a spectacular image revealing new details of violent collisions involving at least four clusters of galaxies.

Combined with an earlier image from NASA's Hubble Space Telescope (HST), the new observations show a complex region more than 5 billion light-years from Earth where the collisions are triggering a host of phenomena that scientists still are working to understand.

The HST image forms the background of this composite, with the X-ray emission detected by Chandra in blue and radio emission seen by the VLA in red.

The X-rays indicate hot, tenuous gas that pervades the region containing the galaxy clusters.

The large, oddly-shaped red feature at the center probably is a region where shocks caused by the collisions are accelerating particles that then interact with magnetic fields and emit the radio waves.

"The complex shape of this region is unique; we've never spotted anything like this before," said Reinout van Weeren, an Einstein Fellow at the Harvard-Smithsonian Center for Astrophysics (CfA).

"The shape probably is the result of the multiple ongoing collisions," he added.

The new radio and X-ray observations are much more sensitive than previous ones, the scientists said. The combination of these images will make this region one of the best-studied examples of cluster-cluster collisions yet known, and can yield new insights on the complex interactions during cluster mergers.

Together, the merging clusters are called MACS J0717+3745, which also is one of the HST Frontier Fields for which HST will produce the deepest observations ever.

The scientists presented their findings to the American Astronomical Society's meeting in Boston, Mass.

The straight, elongated radio-emitting object is a foreground galaxy whose central black hole is accelerating jets of particles in two directions. The red object at bottom-left is a radio galaxy that probably is falling into the cluster.