Here’s a wonderful view of the Sombrero Galaxy (M104, NGC 4594) in Virgo. This multi-hour, deep exposure was taken remotely by astrophotographer Ian Sharp from the Siding Spring Observatory in Australia over the past few weeks, with 12 hours of Luminance and 5 hours each on R, G and B channels.
The Sombrero Galaxy is a spiral galaxy that we see edge-on from Earth. Its outer dust lanes and bright central bulge aare visible in this wonderful image. There’s a zoomed out version, below, and you can see more of Ian Sharp’s great imagery at his website.
Here are the details of the equipment Ian Sharp used to take these images:
Optical Tube Assembly RCOS 12.5” F/9 (2857mm focal length) Carbon-Fibre Tube w/TCC2, PIR and FFC
Equatorial Mount Bisque Paramount ME
Imaging Camera Apogee F16M-D9 (KAF-16803) with 7 slot filter wheel
Imaging Camera Filters Astrodon Series II L,R,G,B, Ha (5nm), OIII (3nm) and SII (3nm)
Guide Camera MMOAG with SBIG ST-402ME
The system delivers a 44×44 arcmin FoV operating at .65 arcsec/pixel
Processed entirely in PixInsight.
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We’ve discovered dozens of so-called “hypervelocity stars” — single stars that break the stellar speed limit. But today astronomers multiplied the number of these ‘runaway’ stars by hundreds of thousands. The Virgo Cluster galaxy, M87, has ejected an entire star cluster, throwing it toward us at more than two million miles per hour.
“Astronomers have found runaway stars before, but this is the first time we’ve found a runaway star cluster,” said lead author Nelson Caldwell of the Harvard-Smithsonian Center for Astrophysics, in a press release.
About one in a billion stars travel at a speed roughly three times greater than our Sun (which clocks in at 220 km/s with respect to the galactic center). At a speed that fast, these stars can easily escape the galaxy entirely, traveling rapidly throughout intergalactic space.
But this is the first time an entire star cluster has broken free.
What would cause an entire cluster — hundreds of thousands of stars packed together a million times more closely than in the neighborhood of our Sun — to reach such a tremendous speed?
Single hypervelocity stars have puzzled astronomers for years. But by observing their speed and direction, astronomers can trace these stars backward, finding that some began moving quickly in the Galactic Center. Here, an interaction with the supermassive black hole can kick a star away at an alarming speed. Another option is that a supernova explosion propelled a nearby star to a huge speed.
Caldwell and colleagues think M87 might have two supermassive black holes at its center. The star cluster wandered too close to the pair, which picked off many of the cluster’s outer stars while the inner core remained intact. The black holes then acted like a slingshot, flinging the cluster away at a tremendous speed.
The star cluster is moving so fast it should soon by sailing into intergalactic space. It may already be, but its distance remains unknown.
The team found the globular cluster — dubbed HVGC-1 — with a stroke of luck. They had been analyzing 2,500 globular cluster candidates for years. While a computer algorithm automatically calculated the speed of every cluster, any oddity was analyzed by hand.
Over 1,000 candidates have measured velocities between 500 and 3000 km/s. These speeds are typical for Virgo Cluster members. But HVGC-1 has a radial velocity of -1026 km/s. “This is the most negative, bulk velocity ever measured for an astronomical object not orbiting another object,” writes Caldwell.
“We didn’t expect to find anything moving that fast,” said coauthor Jay Strader of Michigan State University.
Future measurements pinpointing the exact distance to the globular cluster will help shed light on its exact origins.
The paper will be published in The Astrophysics Journal Letters and is available for download here.
While this image isn’t as deep as the Hubble Deep Field, this 14-hour exposure by the Hubble Space Telescope shows objects around a billion times fainter than what can be seen with the human eyes alone. Astronomers say this image also offers a remarkable depth of field that lets us see more than halfway to the edge of the observable Universe.
As well, this image also provides an extraordinary cross-section of the Universe in both distance and age, showing objects at different distances and stages in cosmic history, and ranges from some of our nearest neighbors to objects seen in the early years of the Universe.
Most of the galaxies visible here are members of a huge cluster called CLASS B1608+656, which lies about five billion light-years away. But the field also contains other objects, both significantly closer and far more distant, including quasar QSO-160913+653228 which is so distant its light has taken nine billion years to reach us, two thirds of the time that has elapsed since the Big Bang.
Since the Hubble Deep Field combined 10 days of exposure and the eXtreme Deep Field, or XDF was assembled by combining ten years of observations (with over 2 million seconds of exposure time), this image at 14 hours of exposure may seem “small.” But it shows the power of the Hubble Space Telescope.
Also of note is that this image was “found” in the Hubble Hidden Treasures vault — where members of the public are able to search Hubble’s science for the best overlooked images that have never been seen by a general audience. This image of CLASS B1608+656 has been well-studied by scientists over the years, but this is the first time it has been published in full online.
Take a zooming view through the image in the video below and read more about this image here.
The passage of the northward equinox last week on March 20th means one thing in the minds of many a backyard observer: the start of Messier Marathon season. This is a time of year during which a dedicated observer can conceivably spot all of the objects in Charles Messier’s famous deep sky catalog in the span of one night.
We’ve written about some tips and tricks to completing this challenge previously, as well as the optimal dates for carrying a marathon out. Typically, the New Moon weekend nearest the March equinox is the best time of year for northern hemisphere observers to target all of the objects on Messier’s list. This works because a majority of the Messier objects are clustered into two regions: towards the core of our galaxy in Sagittarius — where the Sun sits during the December solstice — up through the summer triangle constellations of Cygnus, Aquila and Lyra, and in the bowl of Virgo asterism and its super cluster of galaxies that extends northward into the constellation of Coma Berenices. In March through early April the Sun sits in the constellation of Pisces, well away from the galactic plane.
The prospects for completing a Messier marathon in 2014 favor the last weekend on March on the 29th-30th. The Moon reaches New on Sunday, March 30th at 18:45 Universal Time/2:45 PM EDT.
Messier marathons first came into vogue in the early 1970s right around the time Schmidt-Cassegrain and large Dobsonian “light bucket” telescopes came into general use.
Charles Messier began noting the curious objects that he would later incorporate into his famous catalog during the summer of 1758, with his description of the Crab Nebula in Taurus, which would become Messier object number one or M1. Messier was a prolific comet hunter and discovered 21 comets in his lifetime. The catalog was compiled over the span of 13 years from 1771 to 1784. Messier’s original list contained 45 objects, and was later expanded in subsequent editions 103, with Messier’s assistant Pierre Méchain adding six more objects to the catalog. The list is generally tallied at 110 objects, with one famous controversy being M102, which is generally cited as a re-observation of M101 or the galaxy NGC 5866.
The catalog itself contains a grab bag of open and globular clusters, galaxies, planetary and diffuse nebulae, and one double star (M40). The Messier catalog spans the sky down to M7, an object also known as the Ptolemy Cluster, which is the southernmost object on the list at latitude -34 degrees 48’ south.
Messier observed from Paris at latitude +48 degrees 51’ north using two primary telescopes of the almost one dozen that he owned for his discoveries: a 6.4” Gregorian reflector and a 3.5” refractor. Messier knew nothing of the nature of these “faint fuzzies” that he’d periodically stumbled across in his cometary vigil. His original intent was to compile a list of “comet imposters” in the night sky for comet hunters to be aware of in their quests. In his words:
“What made me produce this catalog was the nebula which I had seen in Taurus while I was observing the comet of that year (1758). The shape and brightness of that nebula reminded me so much of a comet, that I undertook to find more of its kind, to save astronomers from confusing these nebulae with comets.”
“Beware, here doth not lie comets,” Messier admonishes future generations of observers. Still, some peculiarities remain in the catalog: why did Messier, for example, include such obvious “non-comets” as the Pleiades (M45), but skip over the brilliant Double Cluster in Perseus?
Alas, such mysteries are known only to Messier, who was interred at the famous Père Lachaise cemetery after his death in 1817. When we visit Paris, we’ll bypass Jim Morison to leave a copy of Burnham’s Celestial Handbook at Messier’s grave.
And just like the road variety, “running the Messier marathon” takes all of the stamina and pacing that a visual athlete can muster. You’ll want to grab M77 and M74 immediately after dusk, or the marathon will be over before it starts. From there, move on up north to the famous Andromeda galaxy (M31) and the scattering of objects around it before settling in for a more leisurely observing pace moving westward through the constellations of Orion, Leo and surrounding objects.
Now towards the approach of local midnight comes the first large group: the Virgo cluster of galaxies extending through Coma Berenices, rising to the east. After this batch, you can catch some quick shut-eye before bagging the Messier objects towards the galactic center and up through Cygnus in the pre-dawn. Plan ahead; M52, M2 and M30 are especially notoriously difficult in the spring dawn sky!
It’s also worth noting your “attitude versus latitude” plays a role as well. To this end, Ed Kotapish compiled this nifty perpetual chart of when the entire Messier catalog is visible from respective latitudes:
“The bounds of the chart are for a variety of objects,” Ed told Universe Today. “I used nautical twilight (when the Sun falls below -12 degrees in elevation) as the starting and ending condition.” Ed also notes that the top curve of the chart on the morning side is bounded by the difficulty in finding troublesome M30, while the left bottom evening boundary is limited by the observability of M110 and M74, which can be a problem for observers at higher latitudes.
Alternate versions of the Messier marathon exist as well, such as imaging or even sketching all 110 objects in one night.
Why complete a Messier marathon? Well, not only does such a feat hone your visual skills as an observer, but it also familiarizes you with the entire catalog… and there’s nothing that says you have to complete it all in one evening, except of course, for bragging rights at the next star party!
Good luck!
-Here’s a handy list of all 110 of the Messier objects in the catalog.
-Be sure to send those pics of Messier objects and more in to Universe Today’sFlickr forum!
Touring the Milky Way’s a blast with this brand new 360-degree interactive panorama. More than 2 million infrared photos taken by NASA’s Spitzer Space Telescope were jigsawed into a 20-gigapixel click-and-zoom mosaic that takes the viewer from tangled nebulae to stellar jets to blast bubbles around supergiant stars.
The new composite, using infrared images taken over the past decade, was compiled by a team led by UW-Madison astronomer Barbara Whitney and unveiled at a TEDactive conference in Vancouver, Canada Thursday. Unlike visual light, infrared penetrates the ubiquitous dust concentrated in the galactic plane to reveal structures otherwise obscured.
Catching a GLIMPSE of the Milky Way in this short video presentation
“For the first time, we can actually measure the large-scale structure of the galaxy using stars rather than gas,” explained Edward Churchwell, UW-Madison professor of astronomy and team co-leader. “We’ve established beyond the shadow of a doubt that our galaxy has a large bar structure that extends halfway out to the sun’s orbit. We know more about where the Milky Way’s spiral arms are.”
Named GLIMPSE360 (Galactic Legacy Mid-Plane Survey Extraordinaire project), the deep infrared survey captures only about 3% of the sky, but because it focuses on the plane of the Milky Way, where stars are most highly concentrated, it shows more than half of all the galaxy’s 300 billion suns.
Using your imagination to hover high above the galactic plane, you’d see the Milky Way is a flat spiral galaxy sporting a stubby bar of stars crossing its central bulge. The solar system occupies a tiny niche in a minor spiral arm called the Orion Spur two-thirds of the way from the center to the edge. At 100,000 light years across, the Milky Way is vast beyond comprehension and yet it’s only one of an estimated 100 billion galaxies in the observable universe.
While you and I sit back and marvel at all the stellar and nebular eye candy, the Spitzer images are helping astronomers determine where the edge of the galaxy lies and location of the spiral arms. GLIMPSE images have already revealed the Milky Way to be larger than previously thought and shot through with bubbles of expanding gas and dust blown by giant stars.
Spitzer can see faint stars in the “backcountry” of our galaxy — the outer, darker regions that went largely unexplored before.
“There are a whole lot more lower-mass stars seen now with Spitzer on a large scale, allowing for a grand study,” said Whitney. “Spitzer is sensitive enough to pick these up and light up the entire ‘countryside’ with star formation.”
The new 360-degree view will also help NASA’s upcoming James Webb Space Telescope target the most interesting sites of star-formation, where it will make even more detailed infrared observations.
When you play around with the interactive mosaic, you’ll notice a few artifacts here and there among the images. Minor stuff. What took some getting used to was how strikingly different familiar nebulae appeared when viewed in infrared instead of visual light. The panorama is also available on the Aladin viewing platform which offers shortcuts to regions of interest.
Neil deGrasse Tyson, astrophysicist and host of the new Cosmos TV series, gave the third line of our “cosmic address” as the Milky Way after ‘Earth’ and ‘Solar System’. After a few minutes with GLIMPSE360 you’ll better appreciate the depth and breadth of our galactic home.
While dust is easy to ignore in small quantities (says the writer looking at her desk), across vast reaches of space this substance plays an important role. Stick enough grains together, the theory goes, and you’ll start to form rocks and eventually planets. On a galaxy-size scale, dust may even effect how the galaxy evolves.
A new survey of 323 galaxies reveals that dust is not only affected by the kinds of stars in the vicinity, but also what the galaxy is made of.
“These dust grains are believed to be fundamental ingredients for the formation of stars and planets, but until now very little was known about their abundance and physical properties in galaxies other than our own Milky Way,” stated lead author Luca Cortese, who is from the Swinburne University of Technology in Melbourne, Australia.
“The properties of grains vary from one galaxy to another – more than we originally expected,” he added. “As dust is heated by starlight, we knew that the frequencies at which grains emit should be related to a galaxy’s star formation activity. However, our results show that galaxies’ chemical history plays an equally important role.”
Data was captured with two cameras on the just-retired Herschel space telescope: Spectral and Photometric Imaging Receiver (SPIRE) and Photodetecting Array Camera and Spectrometer (PACS). These instruments examined different frequencies of dust emission, which shows what the grains are made of. You can see a few of those galaxies in the image above.
“The dust-rich galaxies are typically spiral or irregular, whereas the dust-poor ones are usually elliptical,” the European Space Agency stated. “Dust is gently heated across a range of temperatures by the combined light of all of the stars in each galaxy, with the warmest dust being concentrated in regions where stars are being born.”
Astronomers initially expected that a galaxy with speedy star formation would display more massive and warmer stars in it, corresponding to warmer dust in the galaxy emitting light in short wavelengths.
“However, the data show greater variations than expected from one galaxy to another based on their star formation rates alone, implying that other properties, such as its chemical enrichment, also play an important role,” ESA said.
Is it stretching it too far to think of a Lord of the Rings-esque “Entmoot” when reading the phrase “Council of Giants”? In this case, however, it’s not trees gathering in a circle, but galaxies.
A new map of the galactic neighborhood shows how the Milky Way may be restricted by a bunch of galaxies surrounding and constricting us with gravity.
“All bright galaxies within 20 million light years, including us, are organized in a ‘Local Sheet’ 34-million light years across and only 1.5 million light years thick,” stated Marshall McCall of York University in Canada, who is the sole author of a paper on the subject.
“The Milky Way and Andromeda are encircled by twelve large galaxies arranged in a ring about 24-million light years across. This ‘Council of Giants’ stands in gravitational judgment of the Local Group by restricting its range of influence.”
Here’s why McCall thinks this is the case. Most of the Local Sheet galaxies (the Milky Way, Andromeda, and 10 more of the 14 galaxies) are flattened spiral galaxies with stars still forming. The other other two galaxies are elliptical galaxies where star-forming ceased long ago, and of note, this pair lie on opposite sides of the “Council.”
“Winds expelled in the earliest phases of their development might have shepherded gas towards the Local Group, thereby helping to build the disks of the Milky Way and Andromeda,” the Royal Astronomical Society stated. The spin in this group of galaxies, it added, is unusually aligned, which could have occurred due to the influence of the Milky Way and Andromeda “when the universe was smaller.”
The larger implication is the Local Sheet and Council likely came to be in “a pre-existing sheet-like foundation composed primarily of dark matter”, or a mysterious substance that is not measurable by conventional instruments but detectable on how it influences other objects. McCall stated that on a small scale, this could help us understand more about how the universe is constructed.
Did some of the oldest galaxies grow up quickly? That’s an intriguing possibility raised by a research team that found “mature” galaxies some 12 billion light years away, when the universe was less than 2 billion years old.
“Today the universe is old and filled with galaxies that have largely stopped forming stars, a sign of galactic maturity,” stated Caroline Straatman from the Netherlands’ Leiden University, a graduate student who led the research. “However, in the distant past, galaxies were still actively growing by consuming gas and turning it into stars. This means that mature galaxies are expected to be almost non-existent when the universe was still young.”
Using data from the Magellan Baade Telescope’s FourStar Galaxy Evolution Survey and combining with other observatories, researchers looked at the young universe using near infrared wavelengths and found 15 galaxies at an average of 12 billion light-years away. While the galaxies are faint using visual wavelengths, they were easy to spot in infrared — and hosted as many as 100 billion stars per galaxy, on average.
These galaxies each have a similar mass to the Milky Way, but stopped making stars when the universe was “only 12 percent of its current age”, researchers said. This implies that star-forming happened much more quickly in the past than right now, since the rate is estimated at several hundred times higher than what is observed in the Milky Way now.
It’s not clear what caused the rapid aging, but you can be sure researchers will look into this further. You can read the research in Astrophysical Journal Letters or in preprint version on Arxiv. Other databases used include Hubble’s Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey and the Great Observatories Origins Deep Survey.
Engage! This video shows some results of the the Galaxy and Mass Assembly catalogue, including the real positions of galaxies. The simulated flythrough, with galactic bodies whizzing by, appears like the view from the Starship Enterprise going at high speed.
Unlike that science fiction series, however, the data you’re seeing has charted information in it (although the galaxies have been biggified for our “viewing pleasure.”)
It’s all part of new research showing that galaxies in “vast empty regions” of the Universe are “aligned into delicate strings,” stated the International Centre for Radio Astronomy Research.
“The spaces in the cosmic web are thought to be staggeringly empty,” stated Mehmet Alpaslan, a Ph.D. candidate at St Andrews University, Scotland who led the research. “They might contain just one or two galaxies, as opposed to the hundreds that are found in big clusters.”
His team discovered faint galaxies lined up in areas of space believed to hold practically nothing. The work is part of an emerging set of research looking at voids in the “cosmic web”, or the filaments that are believed to hold galaxies together across great distances.
Alpaslan’s team used a galaxy census — the biggest ever — of the skies in the south created with observations of Australia’s Anglo-Australian Telescope. The arrangement of galaxies in these voids was surprising to researchers.
“We found small strings composed of just a few galaxies penetrating into the voids, a completely new type of structure that we’ve called ‘tendrils’,” stated Alpaslan.
It will be interesting to see what further research reveals. As the press release accompanying this news states, “These aren’t the voids you’re looking for.”
The spin rate of the most distant supermassive black hole has been measured directly, and wow, is it fast. X-ray observations of RX J1131-1231 (RX J1131 for short) show it is whizzing around at almost half the speed of light. Through X-rays, the astronomers were able to peer at the rate of debris fall into the singularity, yielding the speed measurement.
“We estimate that the X-rays are coming from a region in the disk located only about three times the radius of the event horizon — the point of no return for infalling matter,” stated Jon Miller, an an associate professor of astronomy at the University of Michigan and a co-author on the paper. “The black hole must be spinning extremely rapidly to allow a disk to survive at such a small radius.”
Supermassive black holes are embedded in the heart of most galaxies, and are millions or even billions of times for massive than the Sun. This makes the spin speed astonishingly fast, but also gives astronomers clues about how the host galaxy evolved.
“The growth history of a supermassive black hole is encoded in its spin, so studies of spin versus time can allow us study the co-evolution of black holes and their host galaxies,” stated Mark Reynolds, an assistant research scientist in astronomy at University of Michigan, another co-author on the study.
RX J1131 is six billion light-years away from Earth and classified as a quasar, a type of object that occurs when a lot of matter plunges into a supermassive black hole.
“Under normal circumstances, this faraway quasar would be too faint to study. But the researchers were able to take advantage of a sort of natural telescope effect known as gravitational lensing and a lucky alignment of the quasar and a giant elliptical galaxy to get a closer view,” the University of Michigan stated.
“Gravitational lensing, first predicted by Einstein, occurs when the gravity of massive objects acts as a lens to bend, distort and magnify the light from more distant objects as it passes.”
In this case, the researchers used the Chandra X-ray Observatory and the European Space Agency’s XMM-Newton Telescope to capture the X-ray images.
The research was led Rubens Reis, a postdoctoral research fellow in astronomy the University of Michigan. The paper is published today (March 5) in Nature.