Stunning New Image Shows Gravitational Waves As Two Black Holes Merge

by Tia Ghos

Credit: LIGO, NSF, Aurore Simonnet (Sonoma State U.)
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A new illustration shows how a brief blip in a signal from the Laser Interferometer Gravitational-Wave Observatory revealed the inspiraling and merger of two black holes.

A gorgeous new image released by NASA reveals the momentous first detection of gravitational waves rippling through space-time.

Earlier today (Feb. 11) researchers announced the discovery of the elusive, long-sought ripples in space-time that were predicted by Einstein's theory of general relativity more than a century ago.

"We have detected gravitational waves," David Reitze, a physicist at the California Institute of Technology, said today in a news briefing. "We did it!"

The telltale signs of relativity in action showed up as a teensy blip in the data from the Laser Interferometer Gravitational-Wave Observatory — a set of two separate detectors in Hanford, Washington and Livingston, Louisiana. Researchers then used Einstein's equations to reconstruct the galactic event that caused this ripple in the fabric of space-time. [8 Ways You Can See Einstein's Theory of Relativity in Real Life]

From noise to signal

To recreate the stunning image, scientists first started with the messy, ugly signal at the bottom of the image. It looks like random noise to the untrained eye — but the faint uptick in the signal around the middle is actually the signature of a violent cosmic event: the galactic smashup of two black holes merging.

The LIGO first detected the signal at its Livingston, Louisiana, location on Sept. 14, 2015, then again, 7 milliseconds later at a separate detector in Hanford, Washington.

To understand what the image shows it's helpful to understand how the LIGO works. The detector splits a laser beam into two beams that travel down separate 2.5-mile-long (4 kilometers) passageways, before bouncing off mirrors and intersecting at a light detector. Without any other disturbances, the two beams should arrive at that light detector at the same time. But the Sept. 14 gravitational waves created brief fluctuations in the length of those passageways, which changed when the two beams of light arrived at the beam splitter.

"This signal is seen: you can see it even by eye above the ever-present rambling noise that we have in the detector," said Gabriela González, the spokesperson for the LIGO scientific collaboration, in a news briefing. "We know it's real because 7 milliseconds later we saw this same thing in the Hanford detector."

The signal shows a rise in fluctuations that grow more frequent and more powerful before eventually settling down. The fluctuations are in units of strain, or the change in length of the detectors' passageways over the original length. In this instance, the fluctuations in distance detected by LIGO were about a thousand times smaller than the diameter of a proton.

The team then used Einstein's general relativity equations to create computer simulations of what celestial objects caused the waves, when the event occurred, and exactly how it proceeded.

Based on the frequency, the team deduced that the colliding objects were black holes that started with an initial mass of 29 and 36 times the mass of the sun, respectively, Gonzalez said. The amplitude reveals how distant this cosmic collision is from Earth — and it turns out this smashup occurred 1.3 billion years ago.

Cosmic union

The left-hand side of the image shows the two black holes "inspiraling," meaning that as they rotated around each other, the distance between them decreased and they twirled faster and faster.

As the two merged, which is illustrated in the central portion of the image, they ultimately reached half the speed of light, and in a huge reaction, annihilated an amount of mass three times as big as the sun, converting it to energy that shuddered through space-time in the form of gravitational waves. These waves then raced through the galaxy, finally reaching Earth 1.3 billion years later.

The right-hand side of the image shows the final stages of the merger, called the ringdown. At this point, the merged black hole rings like a bell, but this ringing gradually decreases as more energy is transmitted in the form of gravitational waves.

Tomorrow Full Solar Eclipes !

Via The Skeptics' Guide to the Universe

by Lisa Winter

Photo credit: Artist’s concept of supermassive black hole within M60-UCD1. Credit: NASA, ESA, D. Coe, G. Bacon (STScI)

 

Astronomers have recently discovered that a little galaxy has a big secret. Ultra compact dwarf galaxies (UCD) contain about 100 million stars spanning a couple hundred light years. As a comparison, our Milky Way has about 300 billion stars spread across 100,000 light years. Using the Hubble Space Telescope, an international team of astronomers led by Anil Seth of the University of Utah discovered that M60-UCD1 has a supermassive black hole, making it the smallest galaxy ever discovered to have one. The paper was published in Nature.

M60-UCD1 is located about 54 million light years away and is a satellite of the larger elliptical galaxy Messier 60 in the constellation Virgo. The tiny galaxy is only 300 light years across, but the team discovered in September 2013 that it is likely the densest known galaxy. This follow-up study has revealed that a supermassive black hole at the center might be the cause for that.

"We've known for some time that many UCDs are a bit overweight. They just appear to be too heavy for the luminosity of their stars," co-author Steffen Mieske said in a press release. "We had already published a study that suggested this additional weight could come from the presence of supermassive black holes, but it was only a theory. Now, by studying the movement of the stars within M60-UCD1, we have detected the effects of such a black hole at its centre. This is a very exciting result and we want to know how many more UCDs may harbor such extremely massive objects."

Supermassive black holes are the largest known type of black hole, which are over hundreds of thousands of times more massive than our Sun. The supermassive black hole at the center of M60-UCD1 is roughly equal to 20 million solar masses and makes up a whopping 15% of the galaxy’s total mass
“That is pretty amazing, given that the Milky Way is 500 times larger and more than 1000 times heavier than M60-UCD1," Seth explained. "In fact, even though the black hole at the center of our Milky Way galaxy has the mass of 4 million Suns it is still less than 0.01 percent of the Milky Way's total mass, which makes you realize how significant M60-UCD1's black hole really is."

As the black hole and galaxy have such extreme proportions, it became a wonder how they were ever able to form. The team suspects that the galaxy actually used to be much larger, balancing the mass ratios out a bit more. In the past, the galaxy might have been home to as many as 10 billion stars. When crossing near Messier 60, tidal forces from the larger galaxy might have stripped away the vast majority of M60-UCD1’s outer stars.

"This finding suggests that dwarf galaxies may actually be the stripped remnants of larger galaxies that were torn apart during collisions with other galaxies, rather than small islands of stars born in isolation," Seth concluded. "We don't know of any other way you could make a black hole so big in an object this small."

If this is true for M60-UCD1, it could be possible that more dwarf galaxies also have massive black holes at the center as well. This could potentially double the amount of known black holes in the Universe.

THE DOG DAYS OF SUMMER

Posted on July 30, 2014 by grammy2kiera

Have you ever heard of star lore? You possibly have, but haven’t even considered that star lore is the name for mythical stories about stars and constellations. It’s a fun subject to delve into, and the summer months are a perfect time for it.

You may have stood outside on a hot summer night and gazed up at the myriad of stars shining across the galaxy. It’s difficult to get the full impact of such an activity if you live in the city or a suburban area, with all the competition of man-made lights. But if you live in the country, or ever get the chance to go camping, you’ll be amazed at the awesome sight overhead.

Orion is an easily identifiable constellation, once you locate the three small (from this distance!) stars that make up his belt. They lie at a slight diagonal, so you can hardly miss them. The Dippers, too, are fairly easy to find. But many of the constellations are a bit trickier to the untrained eye. There are books available with star charts that can help if you’re interested in becoming an amateur astronomer.

 

What made me think of this is the time of year. This time, between early July and mid-August, is known as the Dog Days of Summer. As a child, I didn’t understand the reference, so I asked my parents what it meant. I think my mother made some vague comment about the extreme heat being something only a dog could love, but my dad explained in a bit more detail. According to my dad, it all goes back to the myth of the Dog Star, Sirius.

Sirius is the brightest star in the summer sky, at least here in the northern hemisphere. One reason it appears so bright is because it is so close to earth, whereas many of the other stars are a lot farther away. Sirius, as it happens, is the brightest star in the constellation Canis Major. To my untrained eye, it appears that Sirius is located right where a collar might encircle the dog’s neck. Others may see it differently.

There are many myths surrounding the constellation Canis Major. Some ancient civilizations thought the constellation resembled a hunting bow with an arrow – aimed roughly at Orion. Some of them refer to this constellation, which resembles the shape of a dog, as being one of Orion’s hunting dogs. Others also saw it as a dog, possibly one that belonged to other gods or goddesses, or that it was the fastest dog in the world and a god sent him up to the heavens as a reward for his great speed. Whatever the beliefs, people have, in the past, recognized that when Sirius appears shortly after sunrise, the hot, dry days of summer are upon us. Some even offered red dog sacrifices to appease the gods during this time. Yuck!

I’ve read several middle grade books lately that integrate the stars and even some of the myths surrounding them. One is Winter Sky, by Patricia Reilly Giff.

Another one that I just finished is The Same Stuff as Stars, by Katherine Paterson.

Wish You Weren’t, by Sherrie Petersen, a fellow indie author, also deals in star lore,

and you might want to check out Cycles, by Lois Decker Brown,

and The Candle Star, by Michelle Athearn Isenhoff.

You can find those last two FREE on Amazon.

 

And if you’re into picture books, look for The Little Moon Princess, by Y. J. Lee.

All of these books feature astronomical bodies and are lovely reads.

I hope you all have an opportunity to observe the bright lights up in the heavens, and possibly learn more about them, along with all the other constellations that are out there. If you’ve already explored these distant bodies, I’d love to hear of your experiences. Sharing our knowledge and life experiences is a great way to open doors of friendship and expand our minds and hearts.

HAPPY READING!
Cordelia Dinsmore

New Camera Examines Sauron's Eye

by Stephen Luntz

Photo credit: ESO/J.-L. Beuzit et al./SPHERE Consortium

 

It looks like the Eye of Sauron, but it is actually the best image yet of a planetary system forming.

When astronomers use a new telescope or other piece of equipment for the first time they like to make it special. After all enough money and effort has gone into the process, and there's all the excitement of making sure it works. So for the Spectro-Polarimetric High-contrast Exoplanet Research instrument (SPHERE) they picked a star that looks remarkably like the Eye of Sauron.

The purpose of SPHERE is so exciting it didn't really need anything special, but its operators gave it a beginning to remember anyway. Its purpose is to directly view planets around other stars. Although this has been done before, only a handful of planets with just the right combination of characteristics have been able to be imaged this way since 2004.

A new generation of cameras, including SPHERE and the Gemini Planet Imager, hope to change that. The first essential feature is a disk, called a coronagraph, to block the light of the star so that the planet does not get lost in the glare. 

However, for any telescope located within the Earth's atmosphere this can only do so much – some of the light will have been scattered before it reaches the telescope. Adaptive optics help here, adjusting the shape of the mirrors to balance out what the air above is doing. Planets can polarise the light they reflect, so the capacity to detect polarization is also important.

The European Southern Observatory (ESO) notes that SPHERE uses another mechanism to pick the tiny planetary signal from the noise of stellar glare. The make it, “Take many pictures of an object, but with a significant rotation of the image in between each. Features in the pictures that rotate are artefacts of the imaging process, and features that stay in the same place are real objects in the sky. “

These features also make SPHERE suitable for other work, and one of those is to provide clear images of planetary systems in formation. The image above is of HR 4796A, part of a wide, eight million year old binary system 237 light years away. After blocking out the HR 4796A we are left with a view of the dust surrounding it, which is eventually expected to form into planets. The bright ring is thought to be the result of a planet, as yet not detected directly, whose gravity is tugging the dust into formation, as Saturn's moons do to its rings.

SPHERE is attached to the Very Large Telescope in Chile, and has been praised by its Principal Investigator Jean-Luc Beuzit, who said, “SPHERE is a very complex instrument. Thanks to the hard work of the many people who were involved in its design, construction and installation it has already exceeded our expectations.”

What Would It Look Like If Saturn Approached the Earth?

May 12, 2014 | by Lisa Winter

Photo credit: Yeti Dynamics/YouTube screenshot

We Earthlings are about eight times closer to the Sun than we are to Saturn at our closest point. Even though Saturn’s diameter is about nine times larger than ours, we need powerful telescopes to see anything more than a tiny dot of light. This is kind of a shame, given how many of us are so enamored with Saturn’s trademark rings.

Image that Saturn decided to break out of its orbit and pay Earth a visit. Also image that its intense gravitational pull wouldn’t completely gobble us up.

What would Saturn look like if it came as close as Mars?

Nick at Yeti Dynamics has created a video using data from Voyager and Cassini that helps us answer this very question. From the distance of Mars, Saturn would be brighter than the full moon. Although it would appear quite a bit smaller in the night sky, Saturn reflects nearly four times more light than the moon. Even without a telescope, you would still be able to detect Saturn’s rings at this distance and could possibly even see Titan, its largest moon.

If Saturn kept traveling and became even closer to our planet, it would light up the dark side of the moon and even be close enough that Earth’s penumbral and umbral shadows would be visible on Saturn. If Saturn were to pass through over us (ignoring the planet-ending gravity that would come along with it) we could see the back of the planet that is not lit up from the Sun, giving a very different appearance to the rings.

Of course, Saturn is very comfortable in its orbit and it absolutely will not be swinging into our neck of the solar system. The video is very, very cool and you will want to go full screen on this one.

Galileo’s Moon Drawings, the First Realistic Depictions of the Moon in History (1609-1610)

in Astronomy, Science | January 30th, 2014 7 Comments

Galileo Galilei did not invent the telescope. The honor is usually reserved for Hans Libbershey, a Dutch eyeglass maker, who was at least the first person to apply for a patent, in 1608.

But Galileo was a very early adopter, and improver, of the instrument. In 1609, he made the drawings above “from life,” the very first realistic renderings of the Moon (now housed at the Biblioteca Nazionale Centrale in Florence). 

Prior to Galileo’s illustrations, Rice University’s Galileo Project informs us, “virtually no one bothered to represent the Moon with its spots the way it actually appeared.” This was in part due to a belief, derived from Aristotle, that the Moon, and every other astral body, was perfect, in contrast to the Earth’s irregularities. 

After his observations, Galileo planned the following year to create an entire series of illustrations, presumably “to show how the shadows of individual features changed with the illumination.” This, however, became unnecessary since “even the Jesuit fathers in Rome were convinced that that the Moon’s surface was uneven.”

Galileo did incorporate his findings into his groundbreaking treatise Sidereus Nuncius (“The Starry Messenger”), published in Latin in March of 1610, in which he promoted the Copernican heliocentric theory with copious evidence (and for which he was eventually placed under house arrest in 1633).

In his treatise, he explained his observations of a coruscated, pitted, and mountainous Moon and included several additional drawings, such as those above and below. (He also made scores of drawings of Jupiter and several constellations.) 

Like many scholars of his day, Galileo was also an accomplished draftsman, as you can plainly see. And like scholars still today, he was required to excel at the fine art of self-promotion, forced not only to compete with his contemporaries, but also to persuade his patrons as well as mollify the institutional authorities.

In title page of Sidereus Nuncius, Galileo introduces himself as “Florentine patrician and public mathematician of the University of Padua” and touts his accomplishments in devising a “spyglass” and observing “the face of the Moon, countless fixed stars, the Milky Way, nebulous stars….”

He is especially proud, however, of his discovery of four moons of Jupiter, which he calls “four planets.” These satellites, he writes, were “unknown by anyone until this day,” and he names them “the Medicean Stars” after his influential patron Cosimo Il de-Medici, duke of Tuscany.

It is a dedication, astronomer Nick Kollerstrom argues, that helped propel Galileo to his position as the “court philosopher” of Florence. In the rough sketch of the waxing Moon below, made in January, 1609, Galileo includes at the top a draft of an astrological nativity of his wealthy sponsor.

  

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Josh Jones is a writer and musician based in Durham, NC. Follow him at @jdmagness