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COMING EVENTS PUBLIC OBSERVING

WETLANDS DISCOVERY CENTER

SUNDAY, MAY 15 8:30 PM

BAND CONCERT SCHEDULE WEDNESDAY 9:00 PM

June 1, June 15 June 29, July 13

PUBLIC OBSERVING

Transit of Mercury Monday, MAY 09

Sunrise—2PM Roof—Parking Garage South of

Lawrence Public Library

President Rick Heschmeyer

rcjbm@sbcglobal.net ALCOR

William Winkler billwink10@yahoo.com

Report from the Officers Astronomers are the equivalent of anti-farmers: like farmers, we depend on the weather for our livelihood but, unlike real farmers, we normally hope for continu-ous clear skies and extended drought conditions. Lately, in northeastern Kansas, the farmers are com-ing out ahead in the weather column. As noted in last months newsletter, May 1 was supposed to be the start of a new era in the history of Astronomy Associ-ates with the transition of public observing to a perma-

nent site at the Baker Wetlands Discovery Center. The advantages are numerous and the long-term hope is that establishing a permanent site for the club will benefit both AAL and the Discovery Center, drawing more visitors to the site during regular hours and establishing a consistent schedule and location for observing which doesn’t need to shift every couple of years. Unfortunately, the entire few days leading up to and including the night of the opening event were cloud covered and/or populated by thun-derstorms. We have rescheduled the special observing event, open to the public, at the Baker Wetlands Discovery Center for SUNDAY MAY 15, starting at 8:30 pm. Club members are STRONGLY encouraged to bring their scopes to this event to help kick off our partnership with the Wetlands Discovery Center. If the response on Facebook

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Volume 42 Number 05 MAY 2016

INSIDE THIS ISSUE

Officer’s Report (continued) 2

SN Aftereffects (continued) 2

Russian Doll Clusters 3

NASA SPACE PLACE 4

Black Hole Behemoth 5

Disk Light Echoes 6

Space Spider 7

James Webb Telescope 7

Russian Dolls (continued) 8

Light Echoes (continued) 8

Makemake Moon (continued) 8

Makemake’s Moon 9

Giant Bubble 10

Behemoth (continued) 10

Of Local Interest– Followup to Public Lecture Proof that ancient supernovae zapped Earth sparks hunt for aftereffects

Two new papers appearing in the journal Nature are “slam-dunk” evidence that energies from supernovae have buffeted our planet, according to astro-physicist Adrian Melott of the University of Kansas. Melott offers his judg-ment of these studies in an associated letter, titled “Supernovae in the neighborhood,” also appearing in Nature. One paper, authored by Anton Wallner and colleagues, proves the existence of ancient seabed deposits of iron-60 isotopes, tracing their source to super-novae occurring about 325 light years from Earth. The second paper, by a team headed by Dieter Breitschwerdt, estimates explosion times of these supernovae, isolating two events: one 1.7 to 3.2 million years ago, and the other 6.5 to 8.7 million years ago.

“This research essentially proves that certain events hap-pened in the not-too-distant past,” said Melott, a professor of physics and astronomy. “They make it clear approxi-mately when they happened and how far away they were. Knowing that, we can consider what the effect may have been with definite numbers. Then we can look for events in the history of the Earth that might be connected to them.” Melott said both supernovae events were beyond the “kill zone” of roughly 30 light years, but they might have had other effects — in-

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About the Astronomy Associates of Lawrence

The club is open to all people interested in sharing their love for astronomy. Monthly meetings are typically on the second Friday of each month and often feature guest speakers, presentations by club members, and a chance to exchange amateur astronomy tips. Approximately the last Sunday of each month we have an open house at the Prairie Park Nature Center. Periodic star parties

are scheduled as well. For more information, please contact the club officers: president, Rick Heschmeyer at

rcjbm@sbcglobal.net; webmaster, Howard Edin, at howard@howardedin.com; AlCor William Winkler, at

billwink10@yahoo.com; or faculty advisor, Prof. Bruce Twarog at btwarog@ku.edu. Because of the flexibility of the schedule due to holidays and alternate events, it is always best to check the Web site for the exact Fridays and Sundays when events are

scheduled. The information about AAL can be found at http://www.physics.ku.edu/AAL/

Copies of the Celestial Mechanic can also be found on the web at http://www.physics.ku.edu/AAL/newsletter

to the announced event scheduled last week is any indication, turnout could be close to 100 or more. Therefore, the more scopes we have set up and the more coordination available, the better it will be for everyone. Even if you don’t want to set up

and/or operate a telescope, PLEASE COME OUT TO HELP. Let Rick Heschmeyer (rcjbm@sbcglobal.net) know so we can get a sense of how many members will be available. We will also be utilizing the 14" scope permanently housed at the Dis-covery Center. Come join the fun and enjoy the dark(er) skies south of town. A map of the Discovery Center location can be found at the AAL website.

TRANSIT OF MERCURY OBSERVING: For 7 hours on May 9th, 2016, Mercury will transit the face of the Sun as seen from Earth, and we will be watching. The planet is too small to be seen without a solar filtered telescope (Caution! Do NOT attempt to observe the sun without appropriate eye protection). Observing starts at sunrise and the transit will last until just before 2 pm. Our observing location will be the top level of the downtown parking gar-age just south of the Lawrence Public Library. This event will continue the busy spring of space-related events sponsored by

the Lawrence Public Library in conjunction with the KU Museums and the KU Physics and Astronomy Department. - See a video on the transit at this link. With the coming of summer, we will also begin the post Band Concert Downtown Observing sessions; see the schedule on pg.1. Any suggestions for improving the club or the newsletter are always welcome.

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cluding influence on human evolution. “Our local research group is working on figur-ing out what the effects were likely to have been,” he said. “We really don’t know. The events weren’t close enough to cause a big mass extinction or severe effects, but not so far away that we can ignore them either. We’re trying to decide if we should expect to have seen any effects on the ground on the Earth.”

Melott said Fields originally conceived of us-ing iron-60 as a telltale isotope to expose historical episodes of neighborhood superno-vae. “In the 1990s he did the calculations and carried it forward,” said Melott. “He said, ‘Hey, look for iron-60. This is a way to find out if there have been supernova near the Earth.’ Five years later came the first indications of superno-vae using iron-60. Now, 20 years later, we’ve got a slam-dunk. So Fields is the one that really got all this going, and it’s just a really nice coincidence that’s he’s coming to KU just as these papers are coming out.”

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"Russian Doll" Galaxy Clusters Reveal Information About Dark Energy

Astronomers have used data from NASA's Chandra X-ray Observatory, ESA's Planck and a large list of optical telescopes to develop a powerful new method for investigating dark energy, the mysterious energy that is currently driving the accelerating expansion of the universe.

The technique takes advantage of the observation that the outer reaches of galaxy clusters, the largest structures in the universe held together by gravity, show similarity in their X-ray emission profiles and sizes. More massive clusters are simply scaled up versions of less massive ones.

"In this sense, galaxy clusters are like Russian dolls, with smaller ones having a similar shape to the larger ones," said Andrea Morandi of the University of Alabama at Huntsville, who led the study. "Knowing this lets us compare them and accurately determine their distances across billions of light years."

By using these galaxy clusters as distance markers, astronomers can measure how quickly the Universe was ex-panding at different times since the Big Bang. According to Einstein's theory of general relativity, the rate of expan-sion is determined by the properties of dark energy plus the amount of matter in the Universe, where the latter is

mostly made up of unseen mate-rial called dark matter.

If the assumed cosmological parameters (e.g., the properties of dark energy or dark matter) are incorrect, then distant clus-ters will not appear to be similar, that is their sizes will be larger or smaller than expected. The cos-mological parameters are then adjusted so that all of the differ-ent clusters, with different mass-es and different distances, ap-pear to be similar. The process is akin to determining the unknown weight of an object by adding or subtracting known weights to a balance scale until the two sides balance.

These latest results confirm earli-er studies that the properties of dark energy have not changed over billions of years. They also support the idea that dark energy is best explained by the "cosmological constant," which Einstein first proposed and is equivalent to the energy of emp-ty space.

"Although we've looked hard at other explanations," said co-author Ming Sun, also of the University of Alabama at Hunts-ville, "it still appears that dark energy behaves just like Ein-stein's cosmological constant."

The researchers studied 320 galaxy clusters with distances from Earth that ranged from about 760 million light years to about 8.7 billion light years. This spans the era where dark energy

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These four galaxy clusters were part of a large survey of over 300 clusters used to investigate dark energy, the mysterious energy that is currently driving the accelerating expansion of the Universe. In these composite images, X-rays from NASA's Chandra X-ray Observatory (purple) have been combined with optical light from the Hubble Space Telescope and Sloan Digital Sky Survey (red, green, and blue).

Researchers used a novel technique that takes advantage of the observation that the outer reaches of galaxy clusters, the largest structures in the universe held together by gravity, show similarity in their X-ray emission profiles and siz-es. That is, more massive clusters are simply scaled up versions of less mas-sive ones, similar to Russian dolls that nest inside one another.

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Hubble Shatters The Cosmic Record For

Most Distant Galaxy

By Ethan Siegel

The farther away you look in the distant universe, the harder it is to see what's out there. This isn't simply because more distant objects appear fainter, although that's true. It isn't because the universe is expanding, and so the light has farther to go before it reaches you, although that's true, too. The reality is that if you built the largest optical telescope you could imagine -- even one that was the size of an entire planet -- you still wouldn't see the new cosmic record-holder that Hubble just discovered: galaxy GN-z11, whose light traveled for 13.4 billion

years, or 97% the age of the universe, before finally reaching our eyes.

There were two special coincidences that had to line up for Hubble to find this: one was a remarkable technical achievement, while the other was pure luck. By extending Hubble's vision away from the ultraviolet and optical and into the infrared, past 800 nanometers all the way out to 1.6 microns, Hubble became sensitive to light that was se-verely stretched and redshifted by the expansion of the universe. The most energetic light that hot, young, newly forming stars produce is the Lyman-α line, which is produced at an ultraviolet wavelength of just 121.567 nanome-ters. But at high redshifts, that line passed not just into the visible but all the way through to the infrared, and for the newly discovered galaxy, GN-z11, its whopping redshift of 11.1 pushed that line all the way out to 1471 nanometers, more than double the limit of visible light!

Hubble itself did the follow-up spectroscopic observations to confirm the existence of this galaxy, but it also got lucky: the only reason this light was visible is because the region of space between this galaxy and our eyes is mostly ion-ized, which isn't true of most locations in the universe at this early time! A redshift of 11.1 corresponds to just 400

million years after the Big Bang, and the hot radiation from young stars doesn't ionize the majority of the universe until 550 million years have passed. In most directions, this galaxy would be invisible, as the neutral gas would block this light, the same way the light from the center of our galaxy is blocked by the dust lanes in the galactic plane. To see farther back, to the universe's first true galaxies, it will take the James Webb Space Telescope. Webb's infrared eyes are much less sensitive to the light-extinction caused by neutral gas than instruments like Hubble. Webb may reach back to a redshift of 15 or even 20 or more, and discover the true answer to one of the universe's greatest mysteries: when the first galaxies came into existence!

Images credit: (top); NASA, ESA, P. Oesch (Yale University), G. Brammer (STScI), P. van Dokkum (Yale University), and G. Illingworth (University of California, Santa Cruz) (bottom), of the galaxy GN-z11, the most distant and highest-redshifted galaxy ever discov-ered and spectroscopically confirmed thus far.

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Behemoth Black Hole Found in an Unlikely Place

Astronomers have uncovered a near-record-breaking supermassive black hole, weighing 17 billion suns, in an unlike-ly place: in the center of a galaxy in a sparsely populated area of the universe. The observations, made by NASA's Hubble Space Telescope and the Gemini telescope in Hawaii, could indicate that these monster objects may be more common than once thought. Until now, the biggest supermassive black holes — those roughly 10 billion times the mass of our sun — have been found at the cores of very large galaxies in regions of the universe packed with other large galaxies. In fact, the current record holder tips the scale at 21 billion suns and resides in the crowded Coma galaxy cluster, which consists of over 1,000 galaxies.

"The newly discovered supersized black hole resides in the center of a massive elliptical galaxy, NGC 1600, located in a cosmic backwater, a small grouping of 20 or so galaxies," said lead discoverer Chung-Pei Ma, a University of California-Berkeley astronomer and head of the MASSIVE Survey, a study of the most massive galaxies and super-massive black holes in the local universe. While finding a gigantic black hole in a massive galaxy in a crowded area of the universe is to be expected — like running across a skyscraper in Manhattan — it seemed less likely they could be found in the universe's small towns.

"There are quite a few galaxies the size of NGC 1600 that reside in average-size galaxy groups," Ma said. "We esti-mate that these smaller groups are about 50 times more abundant than spectacular galaxy clusters like the Coma cluster. So the question now is, ‘Is this the tip of an iceberg?' Maybe there are more monster black holes out there that don't live in a skyscraper in Manhattan, but in a tall building somewhere in the Midwestern plains."

The researchers also were surprised to discover that the black hole is 10 times more massive than they had predict-ed for a galaxy of this mass. Based on previous Hubble surveys of black holes, astronomers had developed a corre-lation between a black hole's mass and the mass of its host galaxy's central bulge of stars — the larger the galaxy bulge, the proportionally more massive the black hole. But for galaxy NGC 1600, the giant black hole's mass far overshadows the mass of its relatively sparse bulge. "It appears that that relation does not work very well with extremely massive black holes; they are a larger fraction of the host galaxy's mass," Ma said.

Ma and her colleagues are reporting the discovery of the black hole, which is located about 200 million light-years from Earth in the direction of the con-stellation Eridanus, in the April 6 issue of the jour-nal Nature. Jens Thomas of the Max Planck Insti-tute for Extraterrestrial Physics, Garching, Germa-ny, is the paper's lead author.

One idea to explain the black hole's monster size is that it merged with another black hole long ago when galaxy interactions were more frequent. When two galaxies merge, their central black holes settle into the core of the new galaxy and orbit each other. Stars falling near the binary black hole, depending on their speed and trajectory, can actu-ally rob momentum from the whirling pair and pick up enough velocity to escape from the galaxy's core. This gravitational interaction causes the black holes to slowly move closer together, eventually merging to form an even larger black hole. The supermassive black hole then continues to grow by gobbling up gas funneled to the core by galaxy collisions. "To become this massive, the black hole would have had a very voracious phase during which it devoured lots of gas," Ma said. The fre-quent meals consumed by NGC 1600 may also be the reason why the galaxy resides in a small town, with few galactic neighbors. NGC 1600 is the most dominant galaxy in its galactic group, at least three times brighter than its neighbors. "Other groups like this rarely have such a large luminosity gap between the brightest and the sec-ond brightest galaxies," Ma said. Most of the galaxy's gas was consumed long ago when the black hole blazed as a

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This computer-simulated image shows a supermassive black hole at the core of a galaxy. The black region in the center rep-resents the black hole's event horizon, where no light can es-cape the massive object's gravitational grip. The black hole's powerful gravity distorts space around it like a funhouse mirror. Light from background stars is stretched and smeared as the stars skim by the black hole.

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Light Echoes Give Clues to Protoplanetary Disk

Imagine you want to measure the size of a room, but it's completely dark. If you shout, you can tell if the space you're in is relatively big or small, depending on how long it takes to hear the echo after it bounces off the wall.

Astronomers use this principle to study objects so distant they can't be seen as more than points. In particular, researchers are interested in calculating how far young stars are from the inner edge of their surrounding pro-toplanetary disks. These disks of gas and dust are sites where planets form over the course of millions of years.

"Understanding protoplanetary disks can help us understand some of the mysteries about exoplanets, the planets in solar systems outside our own," said Huan Meng, postdoctoral research associate at the University of Arizona, Tucson. "We want to know how planets form and why we find large planets called 'hot Jupiters' close to their stars."

Meng is the first author on a new study published in the Astrophysical Journal using data from NASA's Spitzer Space Telescope and four ground-based telescopes to determine the distance from a star to the inner rim of its surrounding protoplanetary disk.

Making the measurement wasn't as simple as laying a ruler on top of a photograph. Doing so would be as impos-sible as using a satellite pho-to of your computer screen to measure the width of the period at the end of this sen-tence.

Instead, researchers used a method called "photo-reverberation," also known as "light echoes." When the cen-tral star brightens, some of the light hits the surrounding disk, causing a delayed “echo.” Scientists measured the time it took for light com-ing directly from the star to reach Earth, then waited for its echo to arrive.

Thanks to Albert Einstein's theory of special relativity, we know that light travels at a constant speed. To deter-mine a given distance, as-tronomers can multiply the speed of light by the time light takes to get from one

point to another.

To take advantage of this formula, scientists needed to find a star with variable emission -- that is, a star that emits radiation in an unpredictable, uneven manner. Our own sun has a fairly stable emission, but a variable star would have unique, detectable changes in radiation that could be used for picking up corresponding light echoes. Young stars, which have variable emission, are the best candidates.

The star used in this study is called YLW 16B and lies about 400 light-years from Earth. YLW 16B has about the same mass as our sun, but at one million years old, it's just a baby compared to our 4.6-billion-year-old home star.

Astronomers combined Spitzer data with observations from ground-based telescopes: the Mayall telescope at Kitt Peak National Observatory in Arizona; the SOAR and SMARTS telescopes in Chile; and the Harold L. Johnson telescope in Mexico. During two nights of observation, researchers saw consistent time lags between the stellar emissions and their echoes in the surrounding disk.

The ground-based observatories detected the shorter-wavelength infrared light emitted directly from the star, and

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This illustration shows a star surrounded by a protoplanetary disk. Material from the thick disk flows along the stars magnetic field lines and is deposited onto the stars surface. When material hits the star, it lights up brightly. The star's irregular illumination allows astronomers to measure the gap between the disk and the star by using a technique called "photo-reverberation" or "light echoes." First, astrono-mers look at how much time it takes for light from the star to arrive at Earth. Then, they compare that with the time it takes for light from the star to bounce off the inner edge of the disk and then arrive at Earth. That time difference is used to measure distance, as the speed of light is constant.

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A Space Spider Watches Over Young Stars

A nebula known as "the Spider" glows fluorescent green in an infrared image from NASA's Spitzer Space Tele-scope and the Two Micron All Sky Survey (2MASS). The Spider, officially named IC 417, lies near a much smaller object called NGC 1931, not pictured in the image. Together, the two are called "The Spider and the Fly" nebulae. Nebulae are clouds of interstellar gas and dust where stars can form.

The Spider, located about 10,000 light-years from Earth in the constellation Auriga, is clearly a site of star for-mation. It resides in the outer part of the Milky Way, almost exactly in the opposite direction from the galactic cen-ter. A group of students, teachers and scientists focused their attention on this region as part of the NASA/IPAC Teacher Archive Research Program (NITARP) in 2015. They worked on identifying new stars in this area.

One of the largest clusters of young stars in the Spider can be seen easily in the image. Toward the right of center, against the black background of space, you can see a bright group of stars called "Stock 8." The light from this cluster carves out a bowl in the nearby dust clouds, seen in the image as green fluff. Along the sinuous tail in the center, and to the left, the groupings of red point sources clumped in the green are also young stars. In the image, infrared wavelengths, which are invisible to the unaided eye, have been assigned visible colors. Light with a wavelength of 1.2 microns, detected by 2MASS, is shown in blue. The Spitzer wavelengths of 3.6 and 4.5 microns are green and red, respectively.

The Future of Space Astronomy:

The Golden Mirrors of the

James Webb Space Telescope

The golden mirrors of NASA's Names Webb Space Telescope are seen in this image inside the clean room at the space agency's Goddard Space Flight Center. The space telescope is undergoing testing ahead of its 2018 launch. Each of the James Webb Space Telescope's mirror segments are about the

size of a coffee table and weighs 46 pounds (20 kilo-grams).

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Spitzer observed the longer-wavelength infrared light from the disk's echo. Because of thick interstellar clouds that block the view from Earth, astronomers could not use visible light to monitor the star. Researchers then calculated how far this light must have traveled during that time lag: about 0.08 astronomical units, which is approximately 8 percent of the distance between Earth and its sun, or one-quarter the diameter of Mercury's orbit. This was slightly smaller than previous estimates with indirect techniques, but consistent with theoretical expectations.

Although this method did not directly measure the height of the disk, researchers were able to determine that the inner edge is relatively thick. Previously, astronomers had used the light echo technique to measure the size of accretion disks of material around supermassive black holes. Since no light escapes from a black hole, research-ers compare light from the inner edge of the accretion disk to light from the outer edge to determine the disk size. This technique is also used to measure the distance to other features near the accretion disk, such as dust and the surrounding fast-moving gas.

While light echoes from supermassive black holes represent delays of days to weeks, scientists measured the light echo from the protoplanetary disk in this study to be a mere 74 seconds. The Spitzer study marks the first time the light echo method was used in the context of protoplanetary disks.

"This new approach can be used for other young stars with planets in the process of forming in a disk around them," said Peter Plavchan, co-author of the study and assistant professor at Missouri State University in Spring-field.

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The researchers will need more Hubble observations to make accurate measurements to determine if the moon's orbit is elliptical or circular. Preliminary estimates indicate that if the moon is in a circular orbit, it completes a circuit around Makemake in 12 days or longer.

Determining the shape of the moon's orbit will help settle the question of its origin. A tight circular orbit means that MK 2 is probably the product of a collision between Makemake and another Kuiper Belt Object. If the moon is in a wide, elongated orbit, it is more likely to be a captured object from the Kuiper Belt. Either event would have likely occurred several billion years ago, when the solar system was young.

The discovery may have solved one mystery about Makemake. Previous infrared studies of the dwarf planet re-vealed that while Makemake's surface is almost entirely bright and very cold, some areas appear warmer than other areas. Astronomers had suggested that this discrepancy may be due to the sun warming discrete dark patches on Makemake's surface. However, unless Makemake is in a special orientation, these dark patches should make the dwarf planet's brightness vary substantially as it rotates. But this amount of variability has never been observed.

These previous infrared data did not have sufficient resolution to separate Makemake from MK 2. The team's rea-nalysis, based on the new Hubble observations, suggests that much of the warmer surface detected previously in infrared light may, in reality, simply have been the dark surface of the companion MK 2. There are several possibil-ities that could explain why the moon would have charcoal-black surface, even though it is orbiting a dwarf planet that is as bright as fresh snow. One idea is that, unlike larger objects such as Makemake, MK 2 is small enough that it cannot gravitationally hold onto a bright, icy crust, which sublimates, changing from solid to gas, under sun-light. This would make the moon similar to comets and other Kuiper Belt Objects, many of which are covered with very dark material.

When Pluto's moon Charon was discovered in 1978, astronomers quickly calculated the mass of the system. Pluto's mass was hundreds of times smaller than the mass originally estimated when it was found in 1930. With Charon's discovery, astronomers suddenly knew something was fundamentally different about Pluto. "That's the kind of transformative measurement that having a satellite can enable," Parker said.

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caused the once-decelerating universe to accelerate, a discovery that shocked many astronomers when it was made almost two decades ago.

To determine more precise results than with the Chandra X-ray data alone, the researchers combined this data with information on the expansion rate of the universe from optical observations of supernovas, and work from Planck on the cosmic microwave background, the leftover radiation from the Big Bang.

"The nature of dark energy is one of the biggest mysteries in physics, so it's crucial to invent new tools for studying its properties, since different methods can have very different assumptions, strengths and weaknesses," said Mo-randi. "We think this new technique has the ability to provide a big leap forward in our understanding of dark ener-gy."

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Hubble Discovers Moon Orbiting the Dwarf Planet Makemake

Peering to the outskirts of our solar system, NASA's Hubble Space Telescope has spotted a small, dark moon or-biting Makemake, the second brightest icy dwarf planet — after Pluto — in the Kuiper Belt. The moon — provision-ally designated S/2015 (136472) 1 and nicknamed MK 2 — is more than 1,300 times fainter than Makemake. MK 2 was seen approximately 13,000 miles from the dwarf planet, and its diameter is estimated to be 100 miles across. Makemake is 870 miles wide. The dwarf planet, discovered in 2005, is named for a creation deity of the Rapa Nui people of Easter Island.

The Kuiper Belt is a vast reservoir of leftover frozen material from the construction of our solar system 4.5 billion years ago and home to several dwarf planets. Some of these worlds have known satellites, but this is the first dis-covery of a companion object to Makemake. Makemake is one of five dwarf planets recognized by the International Astronomical Union. The observations were made in April 2015 with Hubble's Wide Field Camera 3. Hubble's unique ability to see faint objects near bright ones, together with its sharp resolution, allowed astronomers to pluck out the moon from Makemake's glare. The discovery was announced today in a Minor Planet Electronic Circular.

The observing team used the same Hubble technique to observe the moon as they did for finding the small satel-lites of Pluto in 2005, 2011, and 2012. Several previous searches around Makemake had turned up empty. "Our

preliminary estimates show that the moon's orbit seems to be edge-on, and that means that often when you look at the system you are going to miss the moon because it gets lost in the bright glare of Makemake," said Alex Parker of the Southwest Re-search Institute, Boulder, Colorado, who led the image analysis for the observations.

A moon's discovery can provide valua-ble information on the dwarf-planet system. By measuring the moon's orbit, astronomers can calculate a mass for the system and gain insight into its evolution. Uncovering the moon also reinforces the idea that most dwarf planets have satellites.

"Makemake is in the class of rare Pluto-like objects, so finding a com-panion is important," Parker said. "The discovery of this moon has given us an opportunity to study Makemake in far greater detail than we ever would have been able to without the com-panion."

Finding this moon only increases the parallels between Pluto and Make-make. Both objects are already known to be covered in frozen methane. As was done with Pluto, further study of the satellite will easily reveal the den-sity of Makemake, a key result that will indicate if the bulk compositions of Pluto and Makemake are also similar. "This new discovery opens a new chapter in comparative planetology in the outer solar system," said team leader Marc Buie of the Southwest Research Institute, Boulder, Colorado.

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This Hubble Space Telescope image reveals the first moon ever discov-ered around the dwarf planet Makemake. The tiny moon, located just above Makemake in this image, is barely visible because it is almost lost in the glare of the very bright dwarf planet. The moon, nicknamed MK 2, is roughly 100 miles wide and orbits about 13,000 miles from Makemake. Makemake is 1,300 times brighter than its moon and is also much larger, at 870 miles across. The Makemake system is more than 50 times farther than the Earth is from the sun. The pair resides on the outskirts of our solar system in the Kuiper Belt, a vast region of frozen debris from the construction of our solar system 4.5 billion years ago. Previous searches for a moon around Makemake turned up empty. The moon may be in an edge-on orbit, so part of the time it gets lost in the bright glare of Make-make.

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Hubble Sees a Star 'Inflating' a Giant Bubble Twenty-six candles grace NASA's Hubble Space Telescope's birthday cake this year, and now one giant space "balloon" will add to the festivities. Just in time for the 26th anniversary of Hubble's launch on April 24, 1990, the telescope has photographed an enormous, balloon-like bubble being blown into space by a super-hot, massive star. Astronomers trained the iconic telescope on this colorful feature, called the Bubble Nebula, or NGC 7635. The bubble is 7 light-years across — about one-and-a-half times the distance from our sun to its nearest stellar neighbor, Alpha Centauri. The Bubble Nebula lies 7,100 light-years from Earth in the constellation Cassiopeia.

brilliant quasar from material streaming into it that was heated into a glowing plasma. "Now, the black hole is a sleeping giant," Ma said. "The only way we found it was by measuring the velocities of stars near it, which are strongly influenced by the gravity of the black hole. The velocity measurements give us an estimate of the black hole's mass."

The velocity measurements were made by the Gemini Multi-Object Spectrograph (GMOS) on the Gemini North 8-meter telescope on Mauna Kea in Hawaii. GMOS spectroscopically dissected the light from the galaxy's center, revealing stars within 3,000 light-years of the core. Some of these stars are circling around the black hole and avoiding close encounters. However, stars moving on a straighter path away from the core suggest that they had ventured closer to the center and had been slung away, most likely by the twin black holes. Archival Hubble imag-es, taken by the Near Infrared Camera and Multi-Object Spectrometer (NICMOS), support the idea of twin black holes pushing stars away. The NICMOS images revealed that the galaxy's core was unusually faint, indicating a lack of stars close to the galactic center. A star-depleted core distinguishes massive galaxies from standard ellipti-cal galaxies, which are much brighter in their centers. Ma and her colleagues estimated that the amount of stars tossed out of the central region equals 40 billion suns, comparable to ejecting the entire disk of our Milky Way galaxy.

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