A Possible New Planet Around the Second Closest Star System to Earth

An international team of astronomers is announcing the possible discovery of a planet around the second closest star system to us, Barnard’s Star. A mere 6 light-years away, the star is a faint red dwarf which gives off only four hundredths of a percent of the Sun’s light energy. The planet, which could be as massive as 3 Earths, is orbiting at the same distance as Mercury is from the Sun, but is still colder than Saturn and unlikely to harbor life as we know it.

Since the closest star system to us also has a known planet in it, this discovery (if it is confirmed) would make it even more likely that planets are “more common than dirt” out there. Four planetary systems would then be known among the stars 10 light-years or closer. Some 2900 planetary systems (containing almost 4,000 planets) have now been found in our galactic neighborhood.

The new planet, which takes 233 days to orbit, was detected from the very slight “wiggles” that the planet’s gravity (as it goes around) gives to the motion of its star. The wiggles are so small that it took 20 years of observations, using special equipment on various telescopes around the world, to identify them. While it’s still possible that their combined observations have another explanation, the 63 authors on the paper announcing the planet have dug deeply into their data statistics and claim that the planet idea is the most likely explanation. Not all experts in the field agree that this is a definite detection. Instruments of the future, with better ability to detect tiny star wiggles, will ultimately decide if the planet is real.

Our image shows an artist conception of what the the “cold, hostile desert” surface of the planet around Barnard’s Star, with a temperature of -270 degrees Centigrade, might look like. (You will need to take your parka if you go.)

Two Giant Black Holes Whirl at the Core of an Active Galaxy

Using the Hubble Space Telescope, a team of astronomers has found that a superbright (active) galaxy is powered at its core by two supermassive black holes whirling around each other in only a bit more than one year. This remarkable galaxy is called Markarian 231, after the Armenian astronomer who made a catalog of such active galaxies (with unusually bright centers.)

The galaxy is almost 600 million lightyears away, so we cannot see the tiny area in the center which contains the black holes directly. But a detailed study of the ultraviolet light from the core of the galaxy strongly implies that a black hole containing enough material to make 4 million Suns is whirling around a much larger black hole (with mass inside for 150 million Suns.)

Think about those numbers! You would not want to live near such overweight black holes, but luckily they are confined to the central regions of galaxies (including our own Milky Way) and are not a feature of the galactic outskirts where our solar system resides in comparative peace.

The idea that enormous black holes like this can share the same environment is not news to astronomers, but it's nice to have such a clear example. We now know that the giant islands of stars called galaxies probably all started much smaller and have been growing through "mergers" (if you'll pardon our appropriating a word from the world of business.)

Smaller galaxies are "eaten" by larger ones, or two galaxies of equal size are attracted together by their mutual gravity. If the smaller galaxies each contain a big black hole, both black holes will wind up near the center of the merged object. If the original galaxies had orbiting motion around each other, their inner black holes will have some of that motion, and can circle each other until -- later -- their gravity also pulls them together.

The fact that the two black holes in Markarian 231 take only about one year to go around means they will collide in a few hundred thousand years (a long time compared to the presidential nomination season, but short for galaxies.)

When two black holes collide you get -- surprise, surprise -- a bigger black hole. But we have caught Markarian 231 in the act of a small galaxy having been swallowed, but before the two black holes had time to merge. There are stars and huge clouds of gas and dust being pulled in by the pair of black holes and as they are torn apart and whirled around, they give off a lot of energy.

It's that energy of doomed material (before it falls into one or the other black hole) that makes Markarian 231's center so unusually bright.

The method used to find the waltzing, whirling black holes in this galaxy holds promise for finding other pairs of giant black holes in other distant galaxies. And the existence of such pairs of hungry black holes is good evidence that our merger theory of how galaxies "bulk up" is correct.

(By the way, our image, above, is a painting, based on the Hubble data.  As we said, we can't take a picture of the inner part of the galaxy.  But below is a Hubble image of the entire disturbed galaxy with its bright center.)

A Monster Misses a Meal

There is a monster at the heart of our Milky Way Galaxy.  It's a super-massive black hole that has already eaten enough material to make 4 million stars like our Sun!  And, like all black holes, it is still hungry.  

For material to be "eaten" by a black hole, it must come quite close to the black hole "mouth" which astronomers call its event horizon.  Because black holes are the most compressed (squozen) objects in the universe, even overfed monster black holes have relatively small event horizons. Astronomers estimate that the one at the center of our Galaxy is 80 to 100 million miles across.  That's roughly the distance between the Earth and the Sun and is a tiny space in which to put 4 million(!) Suns.

So material near our black holes must come close to that tiny region to serve as food for the monster.  Things further away, like stars, can orbit around the black hole and not get swallowed.  (It is from the movement of such close, but not doomed, stars that we can estimate the gravity of the black hole.)

For the last few years, astronomers who monitor the center of our Galaxy have been predicting that a snack is on its way to the black hole.  A dusty cloud of material which they have nicknamed G2 was going to have a close encounter of the worst kind with the black hole in May 2014.  It was going to be torn apart by the enormous gravity of the monster and some of its material was then going to provide a meal for the black hole.  

When gas clouds (or other food) fall into a black hole, they are whirled around with unbelievable speed just before they fall in, and tend to glow briefly with x-rays and other forms of radiation before they disappear in the event horizon. However, no such flare-up of radiation was seen, even when the world's largest telescopes (like the Keck in Hawaii and the European Very Large Telescope in Chile). 

It appears G2 was not torn apart and consumed, because it wasn't a loose cloud of raw material, but a star with some of its birth material still around it.   The star managed to hold on to its "stuff" and make it away from the black hole, depriving it of a meal at this time.  Sorry, monster.   Better luck next time.

(In the picture, you see G2 in different colors going around the black hole (which is invisible, but whose position is marked by the plus sign.)  The blobs are shown at different times, and are red when G2 was moving away from us, and blue now that it was flung around the black hole and is coming toward us.)

Einstein's Lens Splits Space and Time

This year, we celebrate the 100th anniversary of the first publication of Einstein's greatest masterpiece, the General Theory of Relativity.  Now astronomers using the Hubble Space Telescope have found a remarkable quadruple image of a distant exploding star which helps confirm another of that theory's most "far out" predictions.

The General Theory connects space, time, and gravity in mind-boggling ways.  Strong gravity can actually warp (or bend) space and distort the flow of time.  One example of gravity strong enough to do this is a dense cluster of galaxies, like the one shown on our image.  Everything on this Hubble picture that is not a point of light (everything with a shape) is a galaxy of billions of stars.  The cluster contains many such galaxies orbiting a common center. 

Light from more distant objects behind the cluster has to go through the strong gravity of the cluster on its way to us.  Einstein's theory predicts that as gravity warps space, the light from behind the cluster will have to travel through that warped space and will get twisted and bent in eerie ways.  From the right angle, a single beam of light can be split into four similar images, something called an "Einstein Cross."  That's just what you see in the inset on the picture.

Most amazingly, the four images of the exploding star took slightly different amounts of time to get to us through that warped space, and so we are seeing the same explosion at four different time periods.  By studying the details of such complex "gravitational lenses" (as the distortion by the galaxy cluster is called), astronomers hope to learn more about how all the "stuff" in those galaxies is distributed and how much of it is regular matter and how much is dark matter.

The galaxy cluster only has a catalog number, not a name, but we know it is about 5 billion lightyears away (meaning light, traveling at the fastest permitted speed in the universe, took five billion years to reach us.)  The exploding star appears to be four billion lightyears further than that -- meaning we are seeing its light from 9 billion years ago.  The only reason we can see it at all is that the gravity of the galaxy cluster actually intensifies the light as well as splitting it -- just as Einstein's theory predicts.  

What a wonderful image with which to celebrate the 100th anniversary of a theory that Einstein's called "the happiest thought of my life!"

(Click on the image to see it bigger -- believe me, it's worth it!)

A Baby Galaxy with a Grown-up Black Hole Inside

Using the Hubble and Gemini telescopes, astronomers have found a mystery --  a tiny galaxy that has a huge black hole in its center. That hungry black hole has eaten enough material to make 20 millions Suns!

The baby galaxy is really small -- its diameter is only 300 lightyears.  It's crowded in that little space; it contains about 140 million stars.  (Compare it with our Milky Way Galaxy, which stretches over 100,000 lightyears, and contains at least 200 billion stars.  Yet our central black hole has eaten only about 4 millions sun's worth of material.)  How could such a baby galaxy have such a big black hole?

Astronomers are no longer surprised to discover giant black holes at the centers of most galaxies.  Where a galaxy is most crowded (in its middle) is where a black hole (a star corpse with enormous gravity) has the most "food" to eat and can therefore grow.  But, in general, we have found that the larger a galaxy, the larger the monster black hole at its center.  So finding a baby galaxy sporting such a big black hole comes as a huge surprise.

A clue to this mystery comes from the name of the baby galaxy -- its awkward designation is "M60-UCD1."  UCD stands for ultra-compact dwarf (galaxy), which makes sense.   But M60 refers to the 60th entry in Charles Messier's catalog of fuzzy sky objects published in the 1780's.  That Messier catalog features some of the brightest and easiest to see galaxies and nebulae.   There is no way a tiny faint baby galaxy would have made his list!

It turns out that our baby galaxy is orbiting the much larger and brighter galaxy called M60.  In our picture, you see M60, a huge, blimp-shaped "grown-up" galaxy, which has its own super-massive black hole at the center.  You can see our baby galaxy in the inset of the photo. (You may need to click on the image to see it well.)

The fact that our baby galaxy is a "satellite" of the big galaxy may explain the mystery of its small size and big black hole.  The discoverers suggest that in the distant past, our baby was actually a big galaxy, with many more stars (explaining how it got its big black hole.)  But it had a "close encounter" with M60.  The gravity of the big galaxy stripped away its outer stars, leaving the "victim" of this encounter much smaller. 

If M60 took away and absorbed the outer layers of its neighbor, that would make M60 a cosmic cannibal.  That sounds awful, but in recent years astronomers have begun to realize that just about every big galaxy has grown to its present size by cannibalizing some of its smaller neighbors.  

It's a dog-eat-dog world out there among the galaxies, and the big bullies really get to throw their weight around.  Our little galaxy was once a more regular member of the galaxy club, but it lived in a rough neighborhood and got really beaten up by the local gravity bully.  Now it's a mere shadow of its former self.  

Explaining the New Discovery about the Big Bang

As you may have heard, a large team of scientists (from many universities and labs) has used a telescope at the South Pole to make ground-breaking measurements of the very first instants oftime after the Big Bang. There's been a lot of media interest in the discovery, and this morning I was part of a team of scientists (including string theorist Brian Greene) who tried to explain the measurements and the ideas behind them on KQED's Forum program with Michael Krasny. You can hear the full hour at:http://www.kqed.org/a/forum/R201403190900

In the photo, you can see the Dark Sector Lab, a research facility just 3/4 of a mile from the Earth's South Pole. It was the antenna at left (BICEP2) that detected and measured microwaves that are the "afterglow" of the big bang.

For decades, physicists have explained some of the most intriguing large-scale properties of the universe by suggesting that, a tiny fraction of time after the big bang, the cosmos underwent a period of tremendous "inflation" (like blowing up a balloon with the breath of a million people, instead of just with your own lung-power.) That sudden increase in the size of the universe can help us to understand many things about cosmic conditions today, some 14 billion years after the big bang.

But did this "inflation" really happen? That's what the experiment at the South Pole set out to discover. If it did, it would have left very subtle imprints on the "cosmic background radiation" (the afterglow of the big bang) which today comes to us in the form of cool microwaves. (Cool here meaning less energetic waves than the light from the screen on which you are reading this post.)

The imprint of inflation was so delicate that it took several years of observations and even more years of massaging the data to tease it out of the microwave maps we make. One of the leaders of the team said during the show that the effect was 1 part in 30 million. But if it's confirmed by other experiments, this will stand as a milestone in our study of the universe. It's a remarkable wedding between the small scale world of atoms and waves (gravity waves making tiny ripples in the fabric of space-time) and the large-scale world of the entire universe.

It's one more piece of evidence that we now live at a time of "precision cosmology" -- being able to measure the properties of the entire cosmos with laboratory accuracy.

Black Hole Research is One Key Reason You Have a Web Browser

Today, astrophysicist Larry Smarr (U of California, San Diego) received the "Golden Goose Award" at the annual meeting of the American Association for the Advancement of Science. The award was conceived to honor scientific research which seems, at first, to have little practical value, but turns out to have a major effect on human life or society. 

(The Golden Goose Award is meant to contrast with the old "Golden Fleece" award, which a former Senator used to give out willy nilly to research he couldn't understand or appreciate.)

In the 1980's, Dr. Smarr and his group were investigating black holes, places where the complete collapse of a dying star has created a warp in the fabric of space and time. Such bizarre star corpses were predicted by Einstein's general theory of relativity, but only reliably discovered in the 1970's. Calculating exactly how the messy collapse of one spinning star (or the collision of two black holes) would affect and change space and time nearby was a real challenge, and required the use of far bigger supercomputers than were available to academics like Smarr at the time.

Dr. Smarr proposed to the National Science Foundation that the US should create a civilian center for super-computing to crack really hard problems like his. When the center was created (at the University of Illinois), Smarr became its director. With really good computers, scientists needed software to take best advantage of them. Two members of his software team (Marc Andreessen and Eric Bina) created a piece of software in 1993 called MOSAIC, which was an easy-to-use way of searching and communicating with the world wide web.

MOSAIC was the first web browser and the browsers you now use to read my Facebook post are its descendants (and still use many of its features.) It was only when browsers made it easy for the average person to get involved with the Web that the Web took off and the personal computer revolution began its modern acceleration. And to think it wouldn't have happened if an astrophysicist hadn't been itching to know the details of the neighborhood of a black hole or two.

A Star Explodes in a Nearby Galaxy

The big news from the world of astronomy is that a star has blown itself to pieces in a galaxy not so far, far away. The galaxy has the catalog number M82, and is only between 11 and 12 million light years away. (The nearest independent galaxy is a bit more than 2 million light years away, so, as galaxies go, M82 is one of our neighbors.)

M82 is located in the constellation of Ursa Major (the Big Bear), the same constellation that contains the well-known star pattern called the "Big Dipper." That means it is an easy target for telescopes in the Northern Hemisphere of our planet right now. Both amateur and professional astronomers are glued to their instruments, viewing and analyzing this doomed star.

Our color image, which shows the explosion -- called a supernova -- with an arrow, is from the Katzman Automatic Imagining Telescope at the Lick Observatory near San Jose (It was sent to me by Berkeley astronomer Alex Filippenko, who leads the project to discover exploding stars with this telescope.)

Astronomers are looking at the spectrum (the many different colors of light) from the exploding star. They have already discovered that this is that special kind of supernova which helped astronomers discover that the expansion of the entire universe is speeding up -- and earned them the 2011 Nobel Prize in physics.

Called a Type Ia supernova, this kind of explosion comes when a star corpse called a white dwarf is briefly re-ignited by sucking material from a close neighbor star (don't make any zombie jokes, please.) The energies involved when the white dwarf is overloaded with hot new material and blows up are so great that there is no earthly counterpart to compare them to. We are already seeing material blasting away from the explosion at speeds of 45 million miles per hour!!!

Since these supernovae are so important for understanding the universe (not just its expansion, but also its extent and how the death of old stars leads to the birth of the next generation), we are always grateful to have a nearby example to study.

If you have a telescope and want more information on how to find the galaxy and what equipment you will need to observe the supernova, see the Supernova 2014J pages at the website of Sky & Telescope magazine:http://www.skyandtelescope.com/observing/highlights/Bright-Supernova-in-M82-241477661.html

A Beautiful New Image from the Hubble Telescope

Here is a gorgeous picture of a spiral galaxy, which is part of the Coma Cluster of galaxies, roughly 300 million light years away. This galaxy (of billions of stars), like our own, is shaped like a frisbee -- and we are looking at the disk of the frisbee face-on. Its name is just a catalog number: NGC 4921. You can see its huge encircling "arms" of countless stars, blending their light together. And notice a number of clusters of young stars glowing blue, a little distance out from the center.

But what is amazing about this image, if you look at it for a while, is how many OTHER galaxies are visible through and around NGC 4921! All those structures around the galaxy that are not precise pinpoints of light are other great islands of stars -- each containing billions of stars and planets. The cluster of galaxies which NGC 4921 is part of contains more than a thousand galaxies. And there are more galaxies beyond that cluster. Pictures like this help us remember that our problems and disagreements on Earth are such minor issues when seen from the perspective of the universe.

This image, by the way, was assembled from a number of Hubble Space Telescope images and processed by Roberto Colombari, an Italian astronomical photographer working in Brazil.

Earth-like Planet Discovered in a Ridiculous Orbit

 Astronomers from two continents made a startling announcement last week. They had found a world similar in size and composition to the Earth that orbited its star in only eight and a half hours.... Just think about that for a minute. Our planet takes 365 and a quarter days to complete its orbit. The innermost planet in our system, Mercury, takes 88 days to circle the Sun. The new planet, designated Kepler 78b, takes only about a third of one of our days to orbit its star. In other words, a year on Kepler 78b is only 8.5 hours long -- a two-Earth-year-old toddler on this alien world would already be 2,063 years old in local time!

The planet is a bit larger in size than our Earth, but made of dense rock like our inner planets (and not gas and liquid, like our outer planets.) Since it circles so close to its star, it must be torridly hot, so we imagine its surface is molten rock and not solid like our own crust.  Some are calling it a lava planet.

How can astronomers know so much about a distant world like Kepler 78b? As its name implies, the planet was discovered around a faint star in the constellation of Orion by the Kepler telescope in space. Kepler's camera measures the size of a planet when the planet is seen going across the face of its star and diminishing the star's light briefly. But that can only tell us how big the planet is across, and not what kind of material it's made of.

But once Kepler found the planet, astronomers in the U.S. and Europe used giant telescopes on the ground to find the tiny wiggle the pull of the planet causes in the motion of its star. This "wiggle method" tells us how much pull (gravity or mass) the planet has.

When astronomer combine the size of the planet from Kepler and the mass of the planet from the wiggle method, they can calculate the planet's "density" (mass per unit volume). In this case, all the measurements made it clear this was a dense world, made of rock, just like our Earth.

The mystery is: how did an Earth get SO outrageously close to its star. If it was falling in, what made it stop? We know it couldn't have been born so close to the star, because the star was larger when it was young, and the planet would have been inside the star, where no planet can exist. Kepler 78b is part of a group of strange planets Kepler has been discovering -- all of them too close to their stars for their own good and for our peace of mind.

Stunning Wide-Field Image of a Star Nursery

Every once in a while, I see a new astronomical picture that leaves me with my mouth open, saying "Wow!" The above image, assembled by a talented amateur astronomer, from information taken by a number of different telescopes, is one of those.

This wide-angle view is centered on a cluster of recently-born stars that is known by its catalog number of NGC 2264. Surrounding the adolescent stars is a whole region of cosmic gas and dust -- the raw material from which stars are born. The nearby gas glows with the characteristic red color of its most common constituent -- hydrogen.

At left center is the Cone Nebula, a region of gas and dust in the shape of a sideways dark cone; the energy of bright stars to the right of the cone is eating away at the sides of this thick dusty region, leaving only a cone of thicker material behind.

To the right of the Cone Nebula, you can see an opposite (larger) cone pattern of bright stars stretching rightward. Some people see the lights of a sideways holiday tree in the pattern of bright stars.

At the bottom center of the image, pointing upward into the bluish emptier region (where the energy of freshly made stars is clearing things out), you can see an odd region of gas and dust that is sometimes called "The Fox Fur Nebula." Click on the picture and take a good look -- can you see the head of a furry red fox pointing upward into the bluish region?

The entire complex of stars and gas and dust is about 2,600 lightyears away, which means the light we see tonight left this region about 2,600 years ago -- a time when humans on Earth lived a much more challenging existence and lifespans were less than half of what we enjoy today.

This remarkable picture was assembled by Dr. Robert Gendler, a physician and amateur astronomer, who is a master at working with photographic information using his computer. The image was constructed from information provided by the Subaru Telescope in Japan and the Digitized Sky Survey, put together by astronomers at the Space Telescope Science Institute from a number of earlier surveys of the sky. To see more information about the photo, see:
http://www.robgendlerastropics.com/Cone-Subaru-DSS.html

You can go to Dr. Gendler's home page at that site and then browse his many other wonderful images. But take a minute and just enjoy a full-screen version of the picture -- you are seeing the same process of star birth that gave rise to our Sun some five billion years ago.

Mysterious Bursts of Radio Waves

An international team of astronomers has found a new kind of astronomical event in the universe -- a powerful flash of radio waves, lasting only a few thousandth of a second, but coming from vast distances away.

Radio waves -- the same kind of invisible "wireless waves" that bring news of traffic jams to our car radios or wifi for our laptop computers -- come from a variety of natural events in the cosmos. If your car radio were to convert them to sound waves, they would sound like static. Radio static comes to us from the magnetic regions of the Sun and Jupiter, from remnants of exploded stars, and many other sources in the sky. But the "transmissions" usually last a long time.

A sudden burst of such waves lasting only a few thousandth of a second (and then never again) came as a surprise to astronomers. The first of these was discovered six years ago, but was classified as doubtful until others could be found. Now astronomers have found a total of five from different directions in the sky. Indications are that they come from far away -- from far beyond our Milky Way Galaxy. If so, and we can still detect them from Earth, they must be very strong bursts indeed. (In the same way, if you scan the horizon and see a flash of light from a distant city, whatever made the light must be quite bright to cross the space between cities and still be visible to your eyes.)

What could make such brief, super-strong bursts of radio waves? It must be something small and powerful. First candidates include the collapsed corpses of stars that are called neutron stars. These are what remains of stars that exploded long ago, and they can pack more than a Sun's worth of material into a ball no bigger than a suburban town (about 20 miles across!) When such densely packed star corpses collapse further or have a magnetic hiccup, they can give off a quick shot of radio energy.

But at this point, no one really knows what sorts of cosmic objects the radio bursts come from and we are eagerly searching for more. This situation is very similar to what happened in 1967 with another kind of invisible wave, called gamma rays. A secret spy satellite found a few bursts of gamma rays coming from space. At first, no one could figure our what they were and why we saw them randomly around the sky. But as decades passed, and we detected more and more of them, with better and better instruments, we learned a lot more about them and began to come up with really good explanations for these "gamma-ray bursts." We may be at the beginning of a similar era of further exploration and gradual explanation with these radio bursts. As they say on the radio, "stay tuned."

(The artistic image with this post shows the radio telescope in Australia that found the new bursts, together with a blue dot symbolizing the (invisible) burst, some distance away from a map of radio waves coming from our own Milky Way, shown with reddish colors. So only the color of the telescope is real, the other colors try to show things our eyes cannot see, using colors we can see. But how else can we have a nice picture with the story?)

Galaxy with a Tail Shows How Some Galaxies Run Out of Gas

In a galaxy with lots of raw material (like our own Milky Way), baby stars are forming all the time.  But some galaxies have run out of the gas (and dust) for making new stars, leaving them barren, with no further opportunities for "childbirth."  Now a new observation of a small galaxy shows how the raw material for stars can be stripped out of a galaxy by outside circumstances.

This is not the first time astronomers have been intrigued by the appearance of the little galaxy known by its catalog number IC3418.  In 2010, the GALEX satellite observed ultraviolet light from the galaxy and first revealed that it had a "tail" -- streamers of gas that had been removed from IC3418 and were following behind it.  Now, new research gives us a better understanding of just how the little galaxy got stripped of its life-giving gas.

IC3418 is falling through a giant collection of galaxies called the Virgo Cluster.  Consisting of some 1,500 galaxies and lots of superhot gas, the Virgo Cluster is our nearest big cluster of galaxies.  Because the Virgo Cluster is full of hot gas, when little IC3418 falls through it, its own gas is stripped out.  (The cluster's hot gas can't affect the stars of a galaxy, which are heavy, but can strip away the lighter gas.)  It is this stripped away gas you are seeing as a tail in our picture.  The removed gas makes some new stars as it gets compressed and it's their glow we see.  But by leaving its parent galaxy, the gas in the tail deprives IC3418 of the fresh gas it needs to make new stars.

This makes IC3418 an old barren galaxy long before its time. It's as if the interaction with the big Virgo Cluster made it age right before our eyes.  The stripping of gas works so well because the speed with which the little galaxy moves through the cluster is 2 million miles per hour!  (Don't try speeds like this at home without adult supervision.)

For a beautiful picture of some of the thousands of galaxies that make up the Virgo Cluster, check out: http://apod.nasa.gov/apod/ap110422.html

The new observations were reported by a team led by astronomer Jeff Kenney of Yale, and were reported at the meeting of the American Astronomical Society going on this week in Indianapolis.

Black Hole at Center of the Milky Way is Found to be Cooking its Dinner

Astronomers working with the European Herschel Space Observatory have discovered really hot gas in the vicinity of the monster black hole at the center of our Galaxy. Over the years, many lines of evidence have shown us that there is a black hole with enough material to make 4 million Suns at the heart of the Milky Way. The new observations, made using infrared (or heat) rays, show that gases such as water vapor and carbon monoxide have been heated to about 1000 degrees Centigrade within a lightyear of the black hole.

While energy from nearby stars may also be heating this inner gas, the astronomers can't account for so much heat from stars alone. They think that great streamers of gas heading toward the black hole may be colliding and the shock waves from the collisions may be significant contributors to the heating. Some of the streamers of gas will someday be "eaten" by the black hole. In other words, like many a hungry diner, the black hole appears to be "cooking" its dinner in anticipation of eating it.

In fact, other observations have recently shown a cloud of gas weighing as much as several Earths, falling to its doom much closer to the black hole. This cloud may be consumed by the black hole as soon as the end of 2013. When such clouds actually spiral inward to their doom, they heat up a lot at the end. The last thing we observe from them before they fall into the black hole (and are no longer visible) is a "burp" of x-rays. Several x-ray telescopes in space are prepared to record such burps when they happen.

If you are cooking a barbecue this Memorial Day Weekend (a holiday in the U.S.), you can enjoy the idea that some serious cooking may also be going on at the center of our Galaxy. The center region is 26,000 lightyears away from us, so none of this poses the least danger to planet Earth and its cooks.

(By the way, to see one of the lines of evidence for the existence of the monster black hole, we recommend a great new movie made from observations by astronomer Andrea Ghez' group at UCLA. The movie shows the whirling orbits of stars very close to the black hole, being pulled around by the enormous gravity of the black hole. Check it out at:

http://www.astro.ucla.edu/~ghezgroup/gc/images/media/ghezGC_comp3-18_H264_864.mov

Note that each second of the movie shows two years of star motion. It's enough to make you dizzy.)

A Record Smashing Black Hole Merry-Go-Round

Astronomers using a European telescope in space have found a star and black hole that whip around a common center every two and a half hours, setting a new record for the movement of such weird companions in space. Like a merciless cannibal, the black hole is also stripping the poor star of its outer layers of hot gas and pulling them into its open "mouth."

To understand this system, you must first know that while some stars are single, like our Sun, many stars live in intimate relationships with each other.  Two stars may orbit a common center and spend their lives whirling around in a rhythmic cosmic dance. If one of those stars should be especially massive, it may end its life as a black hole -- a collapsed star corpse so dense that nothing, not even light, can escape from it.

In our present case, the black hole is estimated to contain enough material to make more than three of our Suns.   The little star it shares its dance with, on the other hand, is only about 1/5th the mass of our Sun. As their mutual gravity pulls them around, the star travels at 1.2 million miles per hour while the black hole moves at 90,000 miles per hour.  The two are only 600,000 miles apart (a very small distance for astronomy.)  Compare that to the 93 million miles that separate the Earth from the Sun.

Check out an animated video of this crazy pair of cosmic objects at: http://spaceinvideos.esa.int/Videos/2013/03/MAXI_J1659_152

You can see material being stripped from the living star and swirling in toward the black hole.  It is this doomed material which glows with tell-tale x-rays and identified the system to the XMM-Newton x-ray telescope being operated by the European Space Agency.  We can only detect these x-rays BEFORE the material enters the black hole -- nothing can escape from it once it falls into the black hole itself.

For a quick YouTube video where I explain the basics of what a black hole is, you can see: http://www.youtube.com/watch?v=7DX_cc-IjpY

"Rain" on the Sun: Remarkable Video

Scientists working with the Solar Dynamics Observatory (SDO) -- a Sun-observing mission in space -- have released a wonderful new video of activity on our home star.  I recommend you view it on a nice screen and enjoy the speeded-up action:

http://www.nasa.gov/mission_pages/sdo/news/coronal-rain.html

When the active, seething, magnetic outer layers of the Sun erupt from time to time, they release vast loops and flows of charged particles.  You may have seen iron filings or small nails trapped by a home magnet and aligned into rounded patterns.   In the same way, the Sun's magnetic influence captures some of these particles and they flow back downward toward the Sun along huge rounded loops. Scientists have nicknamed this downward pouring of hot particles "coronal rain" -- after the outermost layer of the Sun, its corona (or glowing crown).

Launched in 2010, SDO is in an orbit 22,000 miles above the Earth, where it can monitor the constantly changing face of the Sun.  The movie you will see was taken on July 19, 2012 and is speeded up so each second you are seeing is six minutes of real time on the Sun.  The music, of course, is added by the film-makers (there is no sound in space), but it's very atmospheric and lets your imagination really accept the down-pouring of charged particles as a kind of rain.

Bear in mind, though, that the round filaments of hot charged particles returning to their home on the Sun are each much longer that the size of planet Earth (which is shown briefly on the video for scale.)  The temperatures that generate the glow in these images are around 90,000 F (50,000 C).  The energies in these burst and showers of particles dwarf our puny activities on Earth, yet are routine for the Sun.