Posted on by Elizabeth Howell

‘Lopsided’ Ghostly Galactic Halo Has Some Starry Surprises

An image of Centaurus A. The halo goes across four degrees in the sky, about eight times the apparent width of the moon seen with the naked eye. The image was taken with the Digitized Sky Survey 2 (DSS2), the MPG/ESO 2.2-metre telescope, and the NASA/ESA Hubble Space Telescope’s Advanced Camera for Surveys (ACS). Credit: ESA/Hubble, NASA, Digitized Sky Survey, MPG/ESO

Centaurus A — that popular target for astrophotographers in the southern hemisphere — has a much wider halo than expected, astronomers revealed. Turns out the galaxy’s ghostly glow is about eight times the apparent width of the full moon in the sky. Examining this halo in more detail could reveal much about how galaxies come together, astronomers said.

It’s relatively easy for scientists to spot the halo around the Milky Way since we are a part of it, but it’s much harder to observe them in other galaxies because they are so faint. Looking at Centaurus A (10 million to 16 million light-years away) required the power of two Hubble Space Telescope instruments: the Advanced Camera for Surveys and the Wide Field Camera 3.

“Tracing this much of a galaxy’s halo gives us surprising insights into a galaxy’s formation, evolution, and composition,” stated lead author Marina Rejkuba of the European Southern Observatory in Germany. “We found more stars scattered in one direction than the other, giving the halo a lopsided shape — which we hadn’t expected.”

The Centaurus A Extreme Deep Field. (Image Courtesy of Astrophotography byRolf Oslen. Used with Permision).
The Centaurus A Extreme Deep Field. (Image Courtesy of Astrophotography byRolf Oslen. Used with Permision).

The astronomers examined a region that is about 295,000 light-years across — more than double the diameter of the Milky Way’s 120,000 light years. The stars inside the glow appeared to have abundant heavier elements, even in the fringes of the galaxy — a contrast to the much lighter hydrogen and helium that are found in the fringes of the Milky Way and nearby spiral galaxies.

It’s possible the heavier stars arose because Centaurus A merged with a spiral galaxy long ago, removing stars from the intruder and sticking in Centaurus A, the astronomers said.

“Even at these extreme distances, we still haven’t reached the edge of Centaurus A’s halo, nor have we detected the very oldest generation of stars,” stated co-author Laura Greggio of Italy’s INAF (Istituto Nzaionale de Astrofisica, or National Institute for Astrophysics).

“This aged generation is very important. The larger stars from it are responsible for manufacturing the heavy elements now found in the bulk of the galaxy’s stars. And even though the large stars are long dead, the smaller stars of the generation still live on and could tell us a great deal.”

The results are available in Astrophysical Journal Letters and in preprint version on Arxiv.

Source: Hubble European Space Agency Information Centre

Posted on by Bob King

Merging Giant Galaxies Sport ‘Blue Bling’ in New Hubble Pic

In this new Hubble image shows two galaxies (yellow, center) from the cluster SDSS J1531+3414 have been found to be merging into one and a "chain" of young stellar super-clusters are seen winding around the galaxies'?? nuclei. The galaxies are surrounded by an egg-shaped blue ring caused by the immense gravity of the cluster bending light from other galaxies beyond it. Credit: NASA/ESA/Grant Tremblay

On a summer night, high above our heads, where the Northern Crown and Herdsman meet, a titanic new galaxy is being born 4.5 billion light years away. You and I can’t see it, but astronomers using the Hubble Space Telescope released photographs today showing the merger of two enormous elliptical galaxies into a future  heavyweight adorned with a dazzling string of super-sized star clusters. 

The two giants, each about 330,000 light years across or more than three times the size of the Milky Way, are members of a large cluster of galaxies called SDSS J1531+3414. They’ve strayed into each other’s paths and are now helpless against the attractive force of gravity which pulls them ever closer.

A few examples of merging galaxies. NASA, ESA, the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University), K. Noll (STScI), and J. Westphal (Caltech)
A few examples of merging galaxies. NASA, ESA, the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University), K. Noll (STScI), and J. Westphal (Caltech)

Galactic mergers are violent events that strip gas, dust and stars away from the galaxies involved and can alter their appearances dramatically, forming large gaseous tails, glowing rings, and warped galactic disks. Stars on the other hand, like so many pinpoints in relatively empty space, pass by one another and rarely collide.

Elliptical galaxies get their name from their oval and spheroidal shapes. They lack the spiral arms, rich reserves of dust and gas and pizza-like flatness that give spiral galaxies like Andromeda and the Milky Way their multi-faceted character. Ellipticals, although incredibly rich in stars and globular clusters, generally appear featureless.

The differences between elliptical and spiral galaxies is easy to see. M87 at left and M74, both photographed with the Hubble Space Telescope. Credit: NASA/ESA
The differences between elliptical and spiral galaxies is easy to see. M87 at left and M74, both photographed with the Hubble Space Telescope. What look like stars around M87 are really globular star clusters. Credit: NASA/ESA

But these two monster ellipticals appear to be different. Unlike their gas-starved brothers and sisters, they’re rich enough in the stuff needed to induce star formation. Take a look at that string of blue blobs stretching across the center – astronomers call it a great example of ‘beads on a string’ star formation. The knotted rope of gaseous filaments with bright patches of new star clusters stems from the same physics which causes rain or water from a faucet to fall in droplets instead of streams. In the case of water, surface tension makes water ‘snap’ into individual droplets; with clouds of galactic gas, gravity is the great congealer.

Close up of the two elliptical galaxies undergoing a merger. The blue blobs are giant star clusters forming from gas colliding and collapsing into stars during the merger. Click for the scientific paper on the topic. Credit: NASA/ESA/Grant Tremblay
Close up of the two elliptical galaxies undergoing a merger. The blue blobs are giant star clusters forming from gas colliding and collapsing into stars during the merger. Click to read the scientific paper on the topic. Credit: NASA/ESA/Grant Tremblay

Nineteen compact clumps of young stars make up the length of this ‘string’, woven together with narrow filaments of hydrogen gas. The star formation spans 100,000 light years, about the size of our galaxy, the Milky Way. Astronomers still aren’t sure if the gas comes directly from the galaxies or has condensed like rain from X-ray-hot halos of gas surrounding both giants.

The blue arcs framing the merger have to do with the galaxy cluster’s enormous gravity, which warps the fabric of space like a lens, bending and focusing the light of more distant background galaxies into curvy strands of blue light. Each represents a highly distorted image of a real object.


Simulation of the Milky Way-Andromeda collision 4 billion years from now

Four billion years from now, Milky Way residents will experience a merger of our own when the Andromeda Galaxy, which has been heading our direction at 300,000 mph for millions of years, arrives on our doorstep. After a few do-si-dos the two galaxies will swallow one another up to form a much larger whirling dervish that some have already dubbed ‘Milkomeda’. Come that day, perhaps our combined galaxies will don a string a blue pearls too.

Posted on by Shannon Hall

Missing Light Crisis: The Universe Seems a Little Too Dark

The Milky Way as seen from Devil's Tower, Wyoming. Image Credit: Wally Pacholka

There are few moments more breathtaking than standing beneath a brilliant starry sky. Thousands of small specks of light mark only the beginning of the vast cosmic arena, with its unimaginable vistas of time and space. The Milky Way, wrapping above in a cosmic sheet of colors and patterns, also hints that there’s more than meets the eye.

Most of us long for these dark nights, far away from the city lights. But a new study suggests the Universe is a little too dark.

The vast reaches of empty space are bridged by filaments of hydrogen and helium. But there’s a disconnect between how bright the large-scale structure of the Universe is expected to be and how bright it actually is.

In a recent study, a team of astronomers led by Juna Kollmeier from the Carnegie Institute for Science found the light from known populations of stars and quasars is not nearly enough to explain observations of intergalactic hydrogen.

In a brightly lit Universe, intergalactic hydrogen will be easily destroyed by energetic photons, meaning images of the large-scale structure will actually appear dimmer. Whereas in a dim Universe, there are fewer photons to destroy the intergalactic hydrogen and images will appear brighter.

Hubble Space Telescope observations of the large-scale structure show a brightly lit Universe. But supercomputer simulations using only the known sources of ultraviolet light produces a dimly lit Universe. The difference is a stunning 400 percent.

Computer simulations of intergalactic hydrogen in a "dimly lit" universe (left) and a "brightly lit" universe (right) that has five times more of the energetic photons that destroy neutral hydrogen atoms. Hubble Space Telescope observations of hydrogen absorption match the picture on the right, but using only the known astronomical sources of ultraviolet light produces the much thicker structures on the left, and a severe mismatch with the observations. Image is credited to Ben Oppenheimer and Juna Kollmeier.
Computer simulations of intergalactic hydrogen in a “dimly lit” universe (left) and a “brightly lit” universe (right) that has five times more of the energetic photons that destroy neutral hydrogen atoms. Image Credit: Ben Oppenheimer / Juna Kollmeier.

Observations indicate that the ionizing photons from hot, young stars are almost always absorbed by gas in the host galaxy, so they never escape to affect intergalactic hydrogen. The necessary culprit could be the known number of quasars, which is far lower than needed to produce the required light.

“Either our accounting of the light from galaxies and quasars is very far off, or there’s some other major source of ionizing photons that we’ve never recognized,” said Kollmeier in a press release. “We are calling this missing light the photon underproduction crisis. But it’s the astronomers who are in crisis — somehow or other, the universe is getting along just fine.”

Strangely, this mismatch only appears in the nearby, relatively well-studied cosmos. In the early Universe, everything adds up.

“The simulations fit the data beautifully in the early universe, and they fit the local data beautifully if we’re allowed to assume that this extra light is really there,” said coauthor Ben Oppenheimer from the University of Colorado. “It’s possible the simulations do not reflect reality, which by itself would be a surprise, because intergalactic hydrogen is the component of the Universe that we think we understand the best.”

So astronomers are attempting to shed light on the missing light.

“The most exciting possibility is that the missing photons are coming from some exotic new source, not galaxies or quasars at all,” said coauthor Neal Katz from the University of Massachusetts at Amherst.

The team is exploring these new sources with vigor. It’s possible that there could be an undiscovered population of quasars in the nearby Universe. Or more exotically, the photons could be created from annihilating dark matter.

“The great thing about a 400 percent discrepancy is that you know something is really wrong,” said coauthor David Weinberg from Ohio State University. “We still don’t know for sure what it is, but at least one thing we thought we knew about the present day universe isn’t true.”

The results were published in The Astrophysical Journal Letters and are available online.

Posted on by Elizabeth Howell

New Horizons Enters ‘Pluto-Space!’ To Celebrate, Here Are Pictures Of The Dwarf Planet

New Horizons
Artist's impression of the New Horizons spacecraft. Image Credit: NASA

After almost nine years on the road, New Horizons is in what NASA calls “Pluto-space”! Earlier today (July 7), the spacecraft Twitter account announced New Horizons is now 29.8 Earth-sun distances (astronomical units) away from the Sun, putting it within the boundaries of Pluto’s eccentric orbit — exciting, since Pluto is the primary science target.

“Didn’t get the word? We’re farther out than Pluto’s minimum distance to the Sun. We’re in ‘Pluto-space’ now!” tweeted the New Horizons account. We’ve included some of the best Pluto pictures below, to date, to celebrate.

And while many are focused on the Pluto encounter itself, NASA is already planning for what to do next for the spacecraft. In mid-June, we  reported that the Hubble Space Telescope was doing a test search for icy Kuiper Belt objects that New Horizons could possibly fly to next.

That test search was successful enough, with two objects found, that Hubble is now doing a full-blown investigation, according to an announcement last week. Hubble will begin that work in July and conclude observations in August. New Horizons is expected to fly by Pluto and its moons in July 2015.

Pluto's surface as viewed from the Hubble Space Telescope in several pictures taken in 2002 and 2003. Though the telescope is a powerful tool, the dwarf planet is so small that it is difficult to resolve its surface. Astronomers noted a bright spot (180 degrees) with an unusual abundance of carbon monoxide frost. Credit: NASA
Pluto’s surface as viewed from the Hubble Space Telescope in several pictures taken in 2002 and 2003. Though the telescope is a powerful tool, the dwarf planet is so small that it is difficult to resolve its surface. Astronomers noted a bright spot (180 degrees) with an unusual abundance of carbon monoxide frost. Credit: NASA
Pluto and its moons, most of which were discovered while New Horizons was in development and en route. Charon was found in 1978, Nix and Hydra in 2005, Kerberos in 2011 and Styz in 2012. The New Horizons mission launched in 2007. Picture taken by the Hubble Space Telescope. Credit: NASA
Pluto and its moons, most of which were discovered while New Horizons was in development and en route. Charon was found in 1978, Nix and Hydra in 2005, Kerberos in 2011 and Styx in 2012. The New Horizons mission launched in 2006. Picture taken by the Hubble Space Telescope. Credit: NASA
Pluto and moons Charon, Hydra and Nix (left) compared to the dwarf planet Eris and its moon Dysmonia (right). This picture was taken before Kerberos and Styx were discovered in 2011 and 2012, respectively. Credit: International Astronomical Union
Pluto and moons Charon, Hydra and Nix (left) compared to the dwarf planet Eris and its moon Dysnomia (right). This picture was taken before Kerberos and Styx were discovered in 2011 and 2012, respectively. Credit: International Astronomical Union
Pluto appears as a faint white dot (see arrow) in this image taken by New Horizons in September 2006, nine months after launch. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Pluto appears as a faint white dot (see arrow) in this image taken by New Horizons in September 2006, nine months after launch. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Pluto and Charon are visible in this 2013 image from New Horizons' LOng Range Reconnaissance Imager (LORRI). It was the first image from the spacecraft showing Charon separated from Pluto. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Pluto and Charon are visible in this 2013 image from New Horizons’ LOng Range Reconnaissance Imager (LORRI). It was the first image from the spacecraft showing Charon separated from Pluto. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Posted on by David Dickinson

The Making of the Pillars of Creation

Credit:

It’s one of the most iconic images of the modern Space Age. In 1995, the Hubble Space Telescope team released an image of towering columns of gas and dust that contained newborn stars in the midst of formation. Dubbed the “Pillars of Creation,” these light-years long tendrils captivated the public imagination and now grace everything from screensavers to coffee mugs. This is a cosmic portrait of our possible past, and the essence of the universe giving birth to new stars and worlds in action.

Now, a study out on Thursday from the 2014 National Astronomy Meeting of the Royal Astronomical Society has shed new light on just how these pillars may have formed. The announcement comes out of Cardiff University, where astronomer Scott Balfour has run computer simulations that closely model the evolution and the outcome of what’s been observed by the Hubble Space Telescope.

The ‘Pillars’ lie in the Eagle Nebula, also known as Messier 16 (M16), which is situated in the constellation Serpens about 7,000 light years distant.  The pillars themselves have formed as intense radiation from young massive stars just beginning to shine erode and sculpt the immense columns.

The location of Messier 16 and the Pillars of Creation in the night sky. Credit: Stellarium.
The location of Messier 16 and the Pillars of Creation in the night sky. Credit: Stellarium.

But as is often the case in early stellar evolution, having massive siblings nearby is bad news for fledgling stars. Such large stars are of the O-type variety, and are more than 16 times as massive as our own Sun. Alnitak in Orion’s belt and the stars of the Trapezium in the Orion Nebula are examples of large O-type stars that can be found in the night sky. But such stars have a “burn fast and die young” credo when it comes to their take on nuclear fusion, spending mere millions of years along the Main Sequence of the Hertzsprung Russell diagram before promptly going supernova. Contrast this with a main sequence life expectancy of 10 billion years for our Sun, and life spans measured in the trillions of years — longer than the current age of the universe — for tiny red dwarf stars. The larger a star you are, the shorter your life span.

Credit:
A capture from the simulation, showing a cross-section 25 by 25 light years square and 0.2 light years thick. The simulation shows how the O-type star “sculpts” its surroundings over the span of 1.6 million years, carving out, in some cases, the famous “pillars”. Credit: S. Balfour/ University of Cardiff.

Such O-Type stars also have surface temperatures at a scorching 30,000 degrees Celsius, contrasted with a relatively ‘chilly’ 5,500 degree Celsius surface temperature for our Sun.

This also results in a prodigious output in energetic ultraviolet radiation by O-type stars, along with a blustery solar wind. This carves out massive bubbles in a typical stellar nursery, and while it may be bad news for planets and stars attempting to form nearby any such tempestuous stars, this wind can also compress and energize colder regions of gas and dust farther out and serve to trigger another round of star formation. Ironically, such stars are thus “cradle robbers” when it comes to potential stellar and planetary formation AND promoters of new star birth.

In his study, Scott looked at the way gas and dust would form in a typical proto-solar nebula over the span of 1.6 million years. Running the simulation over the span of several weeks, the model started with a massive O-type star that formed out of an initial collapsing smooth cloud of gas.

That’s not bad, a simulation where 1 week equals a few hundred million years…

As expected, said massive star did indeed carve out a spherical bubble given the initial conditions. But Scott also found something special: the interactions of the stellar winds with the local gas was much more complex than anticipated, with three basic results: either the bubble continued to expand unimpeded, the front would expand, contract slightly and then become a stationary barrier, or finally, it would expand and then eventually collapse back in on itself back to the source.

The study was notable because it’s only in the second circumstance that the situation is favorable for a new round of star formation that is seen in the Pillars of Creation.

“If I’m right, it means that O-type and other massive stars play a much more complex role than we previously thought in nursing a new generation of stellar siblings to life,” Scott said in a recent press release. “The model neatly produces exactly the same kind of structures seen by astronomers in the classic 1995 image, vindicating the idea that giant O-type stars have a major effect in sculpting their surroundings.”

Such visions as the Pillars of Creation give us a snapshot of a specific stage in stellar evolution and give us a chance to study what we may have looked like, just over four billion years ago. And as simulations such as those announced in this week’s study become more refined, we’ll be able to use them as a predictor and offer a prognosis for a prospective stellar nebula and gain further insight into the secret early lives of stars.

Posted on by Elizabeth Howell

Where To Go After Pluto? Hubble Seeks The Next Target For New Horizons

Artist's impression of New Horizons' encounter with Pluto and Charon. Credit: NASA/Thierry Lombry

It’s going to be a really busy summer for the New Horizons team. While they’re checking out the newly awakened spacecraft to make sure it’s working properly for its close encounter with Pluto next year, NASA is already thinking about where to put it next: possibly towards a Kuiper Belt Object!

So now the Hubble Space Telescope (in Earth orbit) is scoping out icy objects beyond Pluto. Luckily for us, one of the team members — Alex Parker, a planetary astronomer at the University of California, Berkeley, provided an entertaining livetweet of the process — even through a power failure.

There’s far more to Parker’s tweets than we are indicating here; his Twitter feed also has details about the collaborators, for example, so be sure to read through the entire exchange from yesterday. The survey is led by the Southwest Research Institute’s John Spencer.

What astronomers are doing now is a “pilot observation” where the space telescope looks at a spot in the constellation Sagittarius. Controllers will try to turn the telescope at the same rate as what a KBO would be orbiting around the sun. If the method works, stars will look like streaks and the KBOs will look like “pinpoint objects”, NASA stated.

A view of the Hubble Space Telescope from inside space shuttle Atlantis on mission STS-125 in 2009. Credit: NASA
A view of the Hubble Space Telescope from inside space shuttle Atlantis on mission STS-125 in 2009. Credit: NASA

“If the test observation identifies at least two KBOs of a specified brightness it will demonstrate statistically that Hubble has a chance of finding an appropriate KBO for New Horizons to visit. At that point, an additional allotment of observing time will continue the search across a field of view roughly the angular size of the full moon,” NASA said in a press release.

The reason for this step is Hubble is a high-profile telescope, receiving a lot of requests for observing time around the world. The agency wants to ensure that the telescope is being used for the best scientific return possible. NASA also noted the search might be difficult.

“Though Hubble is powerful enough to see galaxies near the horizon of the universe, finding a KBO is a challenging needle-in-haystack search. A typical KBO along the New Horizons trajectory may be no larger than Manhattan Island and as black as charcoal,” NASA stated.

This isn’t the first time the telescope has done a pinch-hit for Plutonian science. Four new moons have been found around Pluto, a discovery that involved Hubble time. The telescope has also looked for dust rings near the dwarf planet (to do a risk analysis for New Horizons’ approach) and done a map of the surface, to help controllers figure out where to target New Horizons.

Posted on by Shannon Hall

The New and Improved Hubble Ultra Deep Field

The Hubble Ultra Deep Field seen in ultraviolet, visible, and infrared light. Image Credit: NASA, ESA, H. Teplitz and M. Rafelski (IPAC/Caltech), A. Koekemoer (STScI), R. Windhorst (Arizona State University), and Z. Levay (STScI)

It’s perhaps one of the most famous images in astronomy. The Hubble Ultra Deep Field displays nearly 10,000 galaxies across the observable Universe in both visible and near-infrared light. The smallest, reddest galaxies are among the youngest known, existing when the Universe was just 800 million years old.

But now, with the addition of ultraviolet light the renowned image is even better than ever.

“We’ve taken new observations with the Hubble Space Telescope and made a new image of this very famous region of the sky — the Hubble Ultra Deep Field — which gives us one of the most comprehensive pictures of galaxy evolution ever obtained,” said Harry Teplitz from Caltech, in a talk presented at the American Astronomical Society meeting in Boston today.

The image has undoubtedly captured the minds of amateurs and provided astronomers with a wealth of data, from which to study galaxies in their most primitive stages.

But there was a caveat: without ultraviolet light, which tells us about the youngest and hottest stars, there was a significant gap in our understanding of these forming galaxies. Between 5 and 10 billion light-years away from us — corresponding to a time period when most of the stars in the Universe were born — we were left in the dark.

Compare the new image to an older version:

The original Hubble Ultra-Deep Field (Credit NASA, ESA, and S. Beckwith (STScI) and the HUDF Team).
The original Hubble Ultra-Deep Field (Credit NASA, ESA, and S. Beckwith (STScI) and the HUDF Team).

Now, with the addition of ultraviolet data to the Hubble Ultra Deep Field, astronomers can see unobscured regions of star formation throughout this time period. It will help us understand how galaxies grew in size from small collections of very hot stars — now visible across the observable Universe — to the elegant structures we see today.

Here’s a ‘pan and zoom’ video version of the new image:

For more information on the new and improved Ultra Deep Field, check out the HubbleSite.

Posted on by Elizabeth Howell

Galaxy Violence Revealed! Cosmic Crash Shows Cluster Crunch

Galaxy clusters MACS J0717+3745 colliding about five billion light-years away from Earth. This is a composite image of visible light from the Hubble Space Telescope (background), X-ray data from the Chandra X-Ray Observatory (blue) and radio waves from the Very Large Array (red).Credit: Van Weeren, et al.; Bill Saxton, NRAO/AUI/NSF; NASA

Shock waves! Fast-moving particles! Magnetic fields! This image has it all. Behold the merging galaxy clusters MACS J0717+3745 about five billion light-years from our planet.

That funny red thing you see in the center is new data from the Karl G. Jansky Very Large Array showing a spot where “shocks caused by the collisions are accelerating particles that then interact with magnetic fields and emit the radio waves,” officials at the National Radio Astronomical Observatory stated.

“The complex shape of this region is unique; we’ve never spotted anything like this before,” stated Reinout van Weeren, an Einstein Fellow at the Harvard-Smithsonian Center for Astrophysics. “The shape probably is the result of the multiple ongoing collisions.”

This is a composite image of new exposures from VLA and the Chandra X-Ray Observatory, with an older image from the Hubble Space Telescope. And if you take a second look, there’s also a black hole: “The straight, elongated radio-emitting object is a foreground galaxy whose central black hole is accelerating jets of particles in two directions,” NRAO added. “The red object at bottom-left is a radio galaxy that probably is falling into the cluster.”

Astronomers presented their findings at the American Astronomical Society meeting this week in Boston.

Source: NRAO

Posted on by David Dickinson

Will an Asteroid Smack Jupiter in 2022?

PHA asteroid 2014 KM4 on approach to Jupiter in late 2021. Credit: the Solar System Dynamics JPL Small-Body Database Browser.

A recent space rock discovery has sent a minor buzz through the community that tracks such objects. And as usual, it has also begun to attract the dubious attention of those less than honorable sites — we won’t dignify them with links — that like to trumpet gloom and doom, and we thought we’d set the record straight, or at very least, head the Woo off at the pass as quickly as possible.

The asteroid in question is 2014 KM4. Discovered earlier this month, this 192 metre space rock safely passed by the Earth-Moon system at 0.17 A.U.s distant on April 21st. No real biggie, as asteroids pass lots closer all the time. For example, we just had a 6-metre asteroid named 2014 KC45 pass about 48,000 miles (about 80,000 kilometres) from the Earth yesterday morning. That’s about twice the distance of the orbit of geosynchronous satellites and 20% the distance to the Moon.

Sure, it’s a dangerous universe out there… you only have to stand in the Barringer Meteor Crater in Arizona outside of Flagstaff or watch the videos of a meteor exploding over Chelyabinsk last year the day after Valentine’s Day to know that. But what makes 2014 KM4 interesting is its orbit and its potential to approach Jupiter in about seven years.

Or not. One dilemma with orbital mechanics is that the precision of a known orbital path relies on the number of observations made and that position gets more and more uncertain as we project an object’s position ahead in space and time. 2014 KM4 is on a 5.08 year orbit inclined 5.2 degrees to the ecliptic plane that brings it juuusst inside the Earth’s orbit — hence the Apollo designation — and out to an aphelion point very near Jupiter at 5.2 A.U.s from the Sun. But that’s only based on 14 observations made over a span of 5 days. The current nominal trajectory sees 2014 KM4 pass about 0.1 A.U. or 15.5 million kilometres from Jupiter on January 16th 2022. That’s inside the orbit of Jupiter’s outermost moons, but comfortably outside of the orbit of the Galilean moons. The current chance of 2014 KM4 actually impacting Jupiter sits at around 1% and the general trend for these kinds of measurements is for the probability to go down as better observations are made. This is just what happened last year when comet 2013 A1 Siding Spring was discovered to pass very close to Mars later this year on October 19th.

We caught up with JPL astronomer Amy Mainzer, Principal Investigator on the NEOWISE project currently hunting for Near Earth Asteroids for her thoughts on the subject.

“The uncertainty in this object’s orbit is huge since it only has a 5 day observational arc,” Mainzer told Universe Today. “A quick check of the JPL NEO orbit page shows that the uncertainty in its semi-major axis is a whopping 0.47 astronomical units! That’s a huge uncertainty.”

“At this point, any possibility of impact with Jupiter is highly uncertain and probably not likely to happen. But it does point out why it’s so important to extend observational arcs out so that we can extend the arc far enough out so that future observers can nab an object when it makes its next appearance.”

Jupiter takes a beating from Comet Shoemaker-Levy 9. Credit: NASA/Hubble Space Telescope team.
Jupiter takes a beating from Comet Shoemaker-Levy 9. Credit: NASA/Hubble Space Telescope team.

IF (that less than 1% “IF”) 2014 KM4 were to hit Jupiter, it would represent the most distant projection ahead in time of such an event. About two decades ago, humanity had a front row seat to the impact of comet Shoemaker-Levy 9 into Jupiter in July 1994. At an estimated 192 metres in size, 2014 KM4 is about the size of the “D” fragment that hit Jupiter on July 17th 1994. 2014 KM4 has an absolute magnitude (for asteroids, this is how bright they’d appear at 1 A.U. distant) of +21.3 and is currently well placed for follow up observations in the constellation Virgo.

And astronomer Nick Howes mentioned to Universe Today that the Faulkes Telescope North may soon be used to make further observations of 2014 KM4. In the meantime, you can enjoy the animation of their observations of another Near-Earth Asteroid, 2014 KP4.

An animation of the motion of PHA asteroid 2014 KP4. Credit: Remanzacco Observatory.
An animation of the motion of PHA asteroid 2014 KP4. Credit: Remanzacco Observatory.

And yes, the 2022 pass of 2014 KM4 near Jupiter will modify the orbit of the asteroid… but not in our direction. Jupiter is a great “goal tender” in this regard, protecting the inner solar system from incoming hazards.

2014 KM4 is well worth keeping an eye on, but will most likely vanish from interest until it returns to our neck of the solar system in 2065. And no, a killer asteroid won’t hit the Earth in 2045, as a CNN iReport (since removed) stated earlier this week… on “March 35th” no less. Pro-tip for all you conspiracy types out there that think “Big NASA” is secretly hiding the next “big one” from the public: when concocting the apocalypse, please refer to a calendar for a fictional date that at least actually exists!

 

Posted on by Bob King

New Supernova Pops in Bright Galaxy M106 in the ‘Hunting Dogs’

The new Type II supernova is nestled up to the nucleus of the galaxy in this photo taken May 21 with a 17-inch telescope. Credit: Gianluca Masi, Francesca Nocentini and Patrick Schmeer

A supergiant star exploded 23.5 million years ago in one of the largest and brightest nearby galaxies. This spring we finally got the news. In April, the Katzman Automatic Imaging Telescope (KAIT) as part of the Lick Observatory Supernova Search, photographed a faint “new star” very close to the bright core of M106, a 9th magnitude galaxy in Canes Venatici the Hunting Dogs. 

The core of a red or blue supergiant moments before exploding as a supernova looks like an onion with multiple elements "burning" through the fusion process to create the heat to stay the force of gravity. Fusion stops at iron. With no energy pouring from the central core to keep the other elements cooking, the star collapses and the rebounding shock wave tears it apart.
The inner core of a red or blue supergiant moments before exploding as a supernova looks like an onion with multiple elements “burning” through the fusion process to create the heat and pressure that stays the force of gravity. Fusion stops at iron. With no energy pouring from the central core to keep the other elements cooking, the star collapses and the rebounding shock wave tears it apart.

A study of its light curve indicated a Type II supernova – the signature of a rare supergiant star ending its life in the most violent way imaginable. A typical supergiant star is 8 to 12 times more massive than the sun and burns at a much hotter temperature, rapidly using up its available fuel supply as it cooks lighter elements like hydrogen and helium into heavier elements within its core. Supergiant lifetimes are measured in the millions of years (10-100 million) compared to the frugal sun’s 11 billion years. When silicon fuses to create iron, a supergiant reaches the end of the line – iron can’t be fused or cooked into another heavier element – and its internal “furnace” shuts down. Gravity takes over and the whole works collapses in upon itself at speeds up to 45,000 miles per second.

When the outer layers reached the core, they crushed it into a dense ball of subatomic particles and send a powerful shock wave back towards the surface that rips the star to shreds. A supernova is born!  Newly-minted radioactive forms of elements like nickel and cobalt are created by the tremendous pressure and heat of the explosion. Their rapid decay into stable forms releases energy that contributes to the supernova’s light.

This Hubble Space Telescope image shows how spectacular M106 truly is. Its spiral arms are dotted with dark lanes of dust, young star clusters rich with hot, blue stars and tufts of pink nebulosity swaddling newborn stars. The galaxy is the 106th entry in the 18th century French astronomer Charles Messier's famous catalog. Credit: NASA / ESA
This Hubble Space Telescope image shows how spectacular M106 truly is. Dark filaments of dust are silhouetted against billions of unresolved suns. Young star clusters rich with hot, blue stars and tufts of pink nebulosity swaddling newborn stars ornament the galaxy’s spiral arms. A supermassive black hole rumbles at the heart of the galaxy. M106 is the 106th entry in Charles Messier’s famous catalog created in the 18th century. It’s located 23.5 million light years away. Credit: NASA / ESA

For two weeks, the supernova in M106 remained pinned at around magnitude +15, too faint to tease out from the galaxy’s bright, compact nucleus for most amateur telescopes. But a photograph taken by Gianluca Masi and team on May 21 indicate it may have brightened somewhat. They estimated its red magnitude – how bright it appears when photographed through a red filter – at +13.5. A spectrum made of the object reveals the ruby emission of hydrogen light, the telltale signature of a Type II supernova event.

At magnitude +9, M106 visible in almost any telescope and easy to find. Start just above the Bowl of the Big Dipper which stands high in the northwestern sky at nightfall in late May. The 5th magnitude stars 5 CVn (5 Canes Venatici) and 3 CVn lie near the galaxy. Star hop from the Bowl to these stars and then over to M106. Stars plotted to mag. +8. Click to enlarge. Stellarium
At magnitude +9, M106 visible in almost any telescope and easy to find. Start just above the Bowl of the Big Dipper which stands high in the northwestern sky at nightfall in late May. The 5th magnitude stars 5 CVn (5 Canes Venatici) and 3 CVn lie near the galaxy. Star hop from the Bowl to these stars and then over to M106. Stars plotted to mag. +8. Click to enlarge. Stellarium

Visually the supernova will appear fainter because our eyes are more sensitive to light in the middle of the rainbow spectrum (green-yellow) than the reds and purple that bracket either side. I made a tentative observation of the object last night using a 15-inch (37-cm) telescope and hope to see it more clearly tonight from a darker sky. We’ll keep you updated on our new visitor’s brightness as more observations and photographs come in. You can also check Dave Bishop’s Latest Supernovae site for more information and current images.

Even if the supernova never gets bright enough to see in your telescope, stop by M106 anyway. It’s big, easy to find and shows lots of interesting structure. Spanning 80,000 light years in diameter, M106 would be faintly visible with the naked eye were it as close as the Andromeda Galaxy. In smaller scopes the galaxy’s bright nucleus stands out in a mottled haze of pearly light; 8-inch(20-cm) and larger instrument reveal the two most prominent spiral arms. M106 is often passed up for the nearby more famous Whirlpool Galaxy (M51). Next time, take the detour. You won’t be disappointed.