mages from Moon Zoo showing trails from tumbling boulders in the Montes Alpes/Vallis Alpes region on the Moon. Credit: NASA/LRO/Moon Zoo.
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There’s probably a great story in this image, if only someone was there to witness it as it happened! This is an image from Moon Zoo, the citizen science project from the Zooniverse that asks people to look at images from the Lunar Reconnaissance Orbiter and search for craters, boulders and more. And often, the Zooites find some very interesting features on the Moon, like this one and the ones below that include tracks from rolling, bounding, tumbling and sometimes bouncing boulders. Then the task for the scientists is to figure out what actually happened to get these boulders moving — was it an impact, are the boulder on the bottom of a hill, or was it some other unknown catalyst? As Zooniverse founder Chris Lintott says, “The Moon has its own landscape that is really quite dramatic, so it’s a world well worth exploring.”
LRO image from Moon Zoo.
Why look for tumbling boulders? Moon Zoo scientist Dr. Katie Joy gave this explanation:
“One of the main reasons we are asking Moon Zoo users to search for scars left behind by tumbling boulders is to help support future lunar exploration initiatives. Boulders that have rolled down hillsides from crater walls, or massifs like the Apollo 17 landing site, provide samples of geologic units that may be high up a hillside and thus difficult to access otherwise by a rover or a manned crew vehicle. If mission planning can include traverses to boulders that have rolled down hills, and we can track these boulders back up to the part of hillside from where they have originated, it provides a neat sampling strategy to accessing more geological units than would have been possible otherwise… Thus we hope to use Moon Zoo user data to produce a map of known boulder tracks (and terminal boulders) across the Moon.”
If you want to join in on the fun of looking for mysteries on the Moon, check out Moon Zoo, or the Zooniverse for more citizen science projects where you can get involved in helping scientists do real science.
Screenshot of Einstein@Home. Image courtesty of B. Knispel of Albert Einstein Institute
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Hooray for citizen scientists! The Einstein@Home project has discovered a unusual pulsar approximately 17,000 light-years away in the constellation Vulpecula. The project works by people “donating” idle time on their home computers. This is the first deep-space discovery by Einstein@Home, and the finding is credited to Chris and Helen Colvin, from Ames, Iowa in the US, and Daniel Gebhardt of Universitat Mainz, Musikinformatik,Germany.
The newly discovered pulsar, PSR J2007+2722, is an isolated neutron star that rotates 41 times per second and has an unusually low magnetic field.
Jim Cordes, Cornell professor of astronomy, said the object is particularly interesting because it is likely a recycled pulsar: a neutron star that once had a companion star from which it acquired mass; but whose companion exploded, kicking it free.
Unlike most pulsars that spin as quickly and steadily, PSR J2007+2722 sits alone in space, and has no orbiting companion star. However, the scientists say they can not rule out that it may be a young pulsar born with an lower-than-usual magnetic field.
“We think there should be more of these disrupted binary pulsars, but there haven’t been that many found,” said Cordes. “No matter what else we find out about it, this pulsar is bound to be extremely interesting for understanding the basic physics of neutron stars and how they form.”
The discovery demonstrates the power of the network used to collect and sort through vast amounts of data, Cordes said.
Einstein@Home was originally organized to find gravitational waves — ripples in space-time — using the Laser Interferometer Gravitational Wave Observatory (LIGO). In 2009, data from the Arecibo Observatory were included in the processing.
Chris and Helen Colvin who were credited with discovering a new pulsar. Image courtesy Chris Colvin.
Einstein@Home is based at the Center for Gravitation and Cosmology at the University of Wisconsin-Milwaukee and at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute, or AEI) in
Hannover, Germany. About one-third of Einstein@Home’s computing capacity is used to search Arecibo data.
Einstein@Home volunteer Daniel Gebhardt from Germany. Image couresty of Gebhardt.
“This is a thrilling moment for Einstein@Home and our volunteers. It proves that public participation can discover new things in our universe,” said Bruce Allen, leader of the Einstein@Home project, AEI director and adjunct professor of physics at the University of Wisconsin-Milwaukee. “I hope it inspires more people to join us to help find other secrets hidden in the data.”
Gebhardt and the Colvins will receive plaques noting their discovery, and all plan to stay involved.
The conveyor belt of the Sun - a large flow of plasma that circulates under the surface - may be responsible for the duration of solar cycles. Image Credit: Science@NASA
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The Sun seems to finally be waking up in earnest from the long slumber of the past cycle. Solar cycles tend to last on average about 11 years, but the last cycle – solar cycle 23 – was 12.5 years long. The cause of the most recent lull in the Sun’s activity is somewhat enigmatic, but it may be explained by the “conveyor belt” of plasma that circulates in the Sun’s chromosphere and photosophere. Just how far this conveyor belt of plasma extends underneath the Sun may heavily influence the duration of solar cycles.
In a recent paper published in Geophysical Research Letters, Dr. Mausumi Dikpati of the High Altitude Observatory National Center for Atmospheric Research in Boulder, Colorado and her team modeled data from the Mount Wilson Observatory for the duration of the last solar cycle. When they analyzed and modeled surface Doppler measurements of the flow of plasma currents that course underneath the surface of the Sun, they discovered that the flow extended all the way to the poles.
This is in contrast to data from previous, average-length solar cycles, in which the meridional plasma flow – or the Sun’s conveyor belt – flowed only to about 60 degrees latitude. This flow is not unlike thermohaline circulation here on Earth, in which the ocean transports heat around the globe.
Dr. Dikpati said in an email interview, “This is the first time that the Sun’s conveyor-belt has been measured accurately enough for two consecutive cycles (cycles 22 spanning approximately 1986-1996.5 and cycle 23 spanning 1996.5-2009). From these data we now know that cycle 22 had a shorter conveyor-belt reaching only to 60-degree latitude, while cycle 23 had a long conveyor-belt extending all the way to the pole.”
The cycles of the Sun are intricately linked to the magnetic field permeating our nearest star. Gigantic loops of the magnetic field of the Sun are what cause sunspots, and as the contours of the magnetic field change over the cycle of the Sun, more or fewer sunspots are seen, as well as solar flares and other activity. There is always a lack of sunspots between the cycles, but the minimum at the end of cycle 23 was unusually long.
The conveyor belt of plasma flowing in the chromosphere and photosphere essentially drags along with it the magnetic flux of the Sun. Because the extent of the conveyor belt reached a higher latitude, it took the magnetic flux longer to return to the equator, resulting in the delay of sunspots marking the onset of cycle 24.
Dr. Dikpati and her team determined that it wasn’t the speed of the flow of plasma conveyor belt that lengthened the solar cycle, but the extent into higher latitudes, and slower return to the equator. Though the speed of the conveyor belt was a bit higher than usual over the past five years, it also stretched much further than during a normal cycle.
Dr. Dikpati said of using data from previous solar cycles to better refine their model of the conveyor belt:
From the same data source (Mount Wilson data from Roger Ulrich) there is evidence of a short conveyor-belt in cycles 19, 20 and 21 also. All these cycles had periods (10.5 years) like cycle 22. Back beyond that we are hoping that others in the community will search for evidence of the latitudinal extent of the conveyor-belt in even earlier cycles. In fact, theory of the conveyor-belt in high-latitudes indicates that a shorter conveyor belt should be more common in the Sun, rather this long conveyor belt in cycle 23 may be the exception. There is already evidence from Mount Wilson data that, at the start of cycle 24, the conveyor-belt is shortening again, suggesting that cycle 24 is going to be more like cycles 19 – 22 in length.
By getting a better model of the interplay between the plasma flow and the Sun’s magnetic field, solar scientists may be able to better predict and explain the length of future and past solar cycles.
Dr. Dikpati said, “The conveyor belt also governs the memory of the Sun about its past magnetic features. This is an important ingredient for building prediction models for solar cycles.”
The green arrow shows the asteroid. The other bright objects are stars in the Milky Way. Credit: Scott Sheppard
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Astronomers have found a new object in a region of Neptune’s orbit, tucked away in a very hard-to-find location, and where no previous object was known to exist. The object, 2008 LC18, is a Trojan asteroid, which refers an asteroid that shares an orbit with a larger planet or moon, but does not collide with it because it orbits around one of the two Lagrangian points of stability. Six other Trojan asteroids have been located around Neptune’s L4 region, but this is the first one found in Neptune’s L5 region.
Scott Sheppard from the Carnegie Institution’s Department of Terrestrial Magnetism and colleagues used a new observational technique that used large dark clouds to block background light from the galactic plane in order to discover the new Neptune Trojan. They used the discovery to estimate the asteroid population there and find that it is probably similar to the asteroid population at Neptune’s L4 point.
“We estimate that the new Neptune Trojan has a diameter of about 100 kilometers and that there are about 150 Neptune Trojans of similar size at L5,” said Sheppard “It matches the population estimates for the L4 Neptune stability region. This makes the Neptune Trojans more numerous than those bodies in the main asteroid belt between Mars and Jupiter. There are fewer Neptune Trojans known simply because they are very faint since they are so far from the Earth and Sun.”
Jupiter has the most Trojans, 4,076 (as of February 2010) but there are four known Mars Trojans and now seven known Neptune Trojans. So far, searches have failed to uncover any similar objects in the orbits of any other planets.
The five Lagrangian points of stability are shown at Neptune. Credit: Scott Sheppard
“The L4 and L5 Neptune Trojan stability regions lie about 60 degrees ahead of and behind the planet, respectively,” said Sheppard “Unlike the other three Lagrangian points, these two areas are particularly stable, so dust and other objects tend to collect there. We found 3 of the 6 known Neptune Trojans in the L4 region in the last several years, but L5 is very difficult to observe because the line-of-sight of the region is near the bright center of our galaxy.”
Sheppard and his team, which included Chad Trujillo from the Gemini Observatory, used images from a digitized all-sky survey to identify places in the stability regions where dust clouds in our galaxy blocked out the background starlight from the galaxy’s plane, providing an observational window to the foreground asteroids. They discovered the L5 Neptune Trojan using the 8.2-meter Japanese Subaru telescope in Hawaii and determined its orbit with Carnegie’s 6.5-meter Magellan telescopes at Las Campanas, Chile.
Because Trojans share their planet’s orbit they are sensitive to the planet’s formation and migration, and astronomers say finding these objects provide clues that may help unlock the answers to fundamental questions about planetary formation and migration.
The region of space is also of interest to the teams from the New Horizon spacecraft, as it will pass through this same area after its encounter with Pluto in 2015.
Looking northeast around midnight on August 12th-13th. The red dot is the Perseid radiant. Although Perseid meteors can appear in any part of the sky, all of their tails will point back to the radiant. Credit: NASA
Just a reminder: It’s time to head up on the roof, to the backyard, the pasture, the mountaintop — wherever you have to go to get away from city lights and watch the Perseid meteor shower. But this year, there’s the added show of a planetary conjuction right at sunset. Venus, Saturn, Mars, tiny Mercury and the crescent Moon pop out of the western twilight in tight conjunction. But then stay tuned to the sky for the Perseids. If you haven’t been out to see them yet, Thursday, August 12 and Friday August 13 should be the peak, and already some locations have been reporting 70-80 meteors an hour. No telescope is required to enjoy these two naked-eye events. See below for a sky map and tips on how to share your experience.
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Want to share the event via Twitter? Follow the hashtag #Meteorwatch and see the Meteorwatch website for all you need to know about watching the Perseids.
On Thursday, Aug. 12, from 3-4 p.m. EDT, astronomer Bill Cooke from NASA’s Marshall Space Flight Center will answer questions in a live chat about the Perseids and the best ways to view it. To view and join the chat, go to this link on Aug. 12 a few minutes before 3 p.m. EDT. A chat window will be active at the bottom of the page. Log in, then Bill will start answering your questions at 3:00 EDT. And then…stay up all night with NASA! Later that night — Aug. 12 — from 11:00 p.m. to 5 a.m. EDT, Bill will take your questions via Web chat. You can also “listen” to the Perseids on that page.
Wildfires in Russia as seen from space by ESA's Envisat satellite. Credit: ESA
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Massive rains in Pakistan, China and Iowa in the US. Drought, heat and unprecedented fires in Russia and western Canada. 2010 is going down as the year of crazy, extreme weather. Is this just a wacky year or a trend of things to come? According to meteorologists, unusual holding patterns in the jet stream in the northern hemisphere are to blame for the extreme weather in Pakistan and Russia. But also, the World Meteorological Organization and other scientists say this type of weather fits patterns predicted by climate scientists, and could be the result of climate change.
“All these things are the kinds of things we would expect to happen as the planet warms up,” said Tom Wagner, a NASA scientist who studies the cryosphere, during an interview on CNN on August 11. “And we are seeing that the planet is warming about .35 degrees per decade. Places like Greenland are warming even faster, like 3.5 degrees per decade. And all these events from heat waves to stronger monsoons, to loss of ice are all consistent with that. Where it gets a little tricky is assigning any specific event to say, the cause of this event is definitely global warming, that is where we get to the edge of the research.”
“This weather is very unusual but there are always extremes every year,” said Andrew Watson from the University of East Anglia’s Environmental Studies. “We can never say that weather in a single year is unequivocal evidence of climate change, if you get many years of extreme weather then that can point to climate change.”
The Intergovernmental Panel on Climate Change (IPCC) has long predicted that rising global temperatures would produce more frequent and intense heat waves, and more severe rainfalls. In its 2007 report, the panel said these trends have already been observed, with an increase in heat waves since 1950, for example.
NOAA measurements show that the combined global surface temperatures for June 2010 are the warmest on record, and Wagner said there are larger conclusions to be drawn from the definite global warming trend. “We are seeing things that haven’t really happened before on the planet, like warming at this specific rate. We think it is very well tied to increasing carbon dioxide in the atmosphere since the late 1800’s caused by humans.”
This graph, based on the comparison of atmospheric samples contained in ice cores and more recent direct measurements, provides evidence that atmospheric CO2 has increased since the Industrial Revolution. (Source: NOAA)
“Not just over 10 years, but we have satellites images, weather station records and other good records going back to the late 1800’s that tells us all about how the planet is warming up,” Wagner said. “Not only that but we have evidence from geologic records, ice cores, and sediment cores from ocean cores. All of this feeds together to show us how the planet is changing.”
Asked if the cycle can be reversed, Wagner replied, “That is the million dollar question. One thing we have to think about is that the planet is changing and we have to deal with that. Ice around Antarctica and Greenland is melting. Sea level is rising right now at 3 millimeters a year. If you just extrapolate that to 100 years, it will rise to at least a foot of sea level rise. But there is the possibility it could be more than that. These are the types of things we need to think about and come up with mitigation strategies to deal with them. We’re doing the research to try and nail down these questions a little more tightly to see how much sea level is going to rise, how much temperatures are going to rise and how are weather patterns going to change.”
Reducing emissions is one thing that everyone can do to help protect the planet and the climate, and climate experts have been saying for years that there needs to be sharp cutbacks in emissions of carbon dioxide and other heat-trapping gases that go into the atmosphere from automobiles, power plants, and other fossil fuel-burning industrial and residential sources.
In the news this week was the huge ice chunk coming loose from a Greenland glacier. Not only is this an indication of warming water, but other problems could develop, such as the large ice chunks getting in the way of shipping lanes or heading towards oil rigs. The high temperatures and fires in Russia are affecting big percentage of the world’s wheat production, and could have an effect on our food supply this coming year.
Not only that, but the wildfires have created a noxious soup of air pollution that is affecting life far beyond just the local regions, JPL reports. Among the pollutants created by wildfires is carbon monoxide, a gas that can pose a variety of health risks at ground level. Carbon monoxide is also an ingredient in the production of ground-level ozone, which causes numerous respiratory problems. As the carbon monoxide from these wildfires is lofted into the atmosphere, it becomes caught in the lower bounds of the mid-latitude jet stream, which swiftly transports it around the globe.
Two movies were created using continuously updated data from the “Eyes on the Earth 3-D” feature, also on NASA’s global climate change website. They show three-day running averages of daily measurements of carbon monoxide present at an altitude of 5.5 kilometers (18,000) feet, along with its global transport.
And in case you are wondering, the recent solar flares have nothing to do with the wildfires — as Ian O’Neill from Discovery space deftly points out.
Image above: Expedition 24 Flight Engineers Doug Wheelock (right) and Tracy Caldwell Dyson work to replace a failed ammonia pump module outside of the International Space Station. Credit: NASA TV
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Overcoming a disappointing spacewalk last weekend, today astronauts Doug Wheelock and Tracy Caldwell Dyson successfully removed the failed ammonia coolant pump module on the S1 truss of the International Space Station. But NASA managers said that at least two more EVAs will be required to complete all the repairs to the critical cooling system. Earlier, it was hoped that two spacewalks total would allow enough time, but it will take at least four. “There were a number of challenges in the first EVA that set us back, but as we looked closer at this, we were hedging our bets at how many EVAs we had ahead of us,” said Spacewalk officer David Beaver at a press briefing following the successful EVA today. “As we have done more and more work in laying this out in a stepwise fashion, it became clear to us early on that this was a much bigger set of EVAs than we originally made time for.”
He added that on orbit, the astronauts have stopped all research in order to save on the cooling system. The complex systems keeps the station from overheating and the six-member crew has relied on just one — instead of the usual two pumps –to handle the cooling ever since the one pump failed during a power surge on July 31.
“The system has been kind to us and we haven’t had any more failures,” Beaver said.
The spare pump will be installed on the S1 truss during a spacewalk that is now scheduled for Monday – originally it was set for Sunday, but NASA managers decided an extra day would help both the astronauts and the teams on the ground preparing for the EVAs.
Wheelock and Caldwell Dyson were able to close the quick disconnect valve for the final fluid connector for the failed ammonia pump module, and then detach the final fluid line from the failed ammonia pump module – which was the problem that couldn’t be overcome on the first spacewalk.
The two astronauts then extracted the pump module and stowed on another location on the truss, and Caldwell Dyson prepared the spare pump for installation on the next spacewalk on Monday.
The spacewalk lasted 7 1/2 hours, slightly shorter than Saturday’s eight-hour marathon, the longest EVA at the ISS without a space shuttle present. Wheelock and Dyson had to use decontamination procedures after the spacewalk just in case some ammonia leaked on their suits.
In response to the power-saving reconfiguration that has had to be done, the science team worked quickly to establish a plan to preserve experiment samples in the Japanese Experiment Module freezer. The on-orbit crew was able to transfer all the samples from the freezer in the Kibo laboratory to an operating freezer. No sciences samples were lost due to the pump module anomaly.
While the crew schedule has been interrupted to support the newly added spacewalks, the payload ground teams have been working closely with mission controllers to preserve and re-plan high priority activities. Other activities that can be rescheduled with little or no impact are being postponed to a later date.
Here’s this week’s Where In The Universe Challenge. You know what to do: take a look at this image and see if you can determine where in the universe this image is from; give yourself extra points if you can name the instrument responsible for the image. We’ll provide the image today, but won’t reveal the answer until later in the week. This gives you a chance to mull over the image and provide your answer/guess in the comment section. Please, no links or extensive explanations of what you think this is — give everyone the chance to guess.
UPDATE: The answer has now been posted below!
Tsk, tsk. A few of you posted links in your answer — that’s not allowed. Remember — no links or extensive explanations.
This rather creepy-looking image could be construed as a cavern or the mouth of monster. It is actually a storm of billowing clouds blown by the winds from massive stars, and set aglow by their light. This is a nebula within cluster NGC1929, known as the N44 superbubble. This particular image was taken by the Gemini Multi-object Spectrograph (GMOS) on the Gemini South Telescope in Chile. You can read more about it on this press release from Gemini, or this previous article on Universe Today, or this ESO article
Five sunspots appeared on the Sun on August 11, 2010. Image from SolarCycle24.com
Here’s something we’ve not seen in a long while: five sunspots on the Sun at once. Is the Sun finally waking up from its unusually long and deep solar minimum slumber? While activity on the Sun usually ebbs and flows on a fairly predictable 11-year cycle, this current cycle has been anything but conventional. In 2009, there were 260 days (71% of the time) that the Sun was ‘spotless,’ but now in 2010 so far, the Sun has had spots been spotless for only 35 days. With the last solar maximum occurring in 2001, maybe the Sun is just now ramping up to the next maximum, which is set for 2013. Recent solar flares on August 1 and 7, and now these sunspots may be signaling that the Sun is “throwing off the covers” and starting to wake up.
This marvelous image from the Solar Dynamics Observatory shows that at about 8:55 UTC on August 1, a measurable solar flare triggered an event known as a coronal mass ejection (CME). This is where the “atmosphere” of the Sun sends out a burst of energized plasma. In this case, nearly the entire Earth-facing side of the Sun was involved.
The High Energy Astrophysics Picture of the week Page used that great “covers” analogy:
The Sun, after a long sleep, is finally waking up. And like any irascible sleeper vigorously throwing off the covers. In this case the covers are composed of high-energy electrons and protons being shot out into space at a tremendous rate. The image above, obtained by the Solar Dynamics Observatory on August 1, shows almost the entire earth-facing side of the sun erupting at once. In this extreme ultraviolet image you can see evidence of extremely ultraviolent activity: a C3-class solar flare (white area on upper left), a solar tsunami (upper right), multiple filaments of magnetism lifting off the stellar surface, large-scale shaking of the solar corona, and a coronal mass ejection. The coronal mass ejection, or CME, showered the earth with charged particles, producing spectacular aurora (northern lights) as far south as Iowa and Telemark, Norway.
And another CME on August 7 has not yet triggered a major geomagnetic storm, but high latitude sky watchers should take a look tonight, just in case.
Astronomers have found unexpected rings and arcs of ultraviolet light around a selection of galaxies, four of which are shown here as viewed by NASA's and the European Space Agency's Hubble Space Telescope. Image credit: NASA/ESA /JPL-Caltech/STScI/UCLA
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Title this ‘Zombie Galaxies’ or ‘Night of the Living Galaxies.’ Astronomers have found mysterious, giant loops of ultraviolet light around old, massive galaxies, which were presumed to be “dead,” and these galaxies seem to have come back to life. Somehow these “over-the-hill galaxies” have been infused with fresh gas to form new stars that power these truly gargantuan rings, some of which could encircle several Milky Way galaxies.
The discovery of these rings implies that old bloated galaxies that were once devoid of star-making can be reignited with star birth, and that galaxy evolution does not proceed straight from the cradle to the grave.
“In a galaxy’s lifetime, it must make the transition from an active, star-forming galaxy to a quiescent galaxy that does not form stars,” said Samir Salim, lead author of a recent study and a research scientist in the department of astronomy at Indiana University, Bloomington. “But it is possible this process goes the other way, too, and that old galaxies can be rejuvenated.”
Using two orbiting observatories, NASA’s Galaxy Evolution Explorer and Hubble Space Telescope, the astronomers surveyed a vast region of the sky in ultraviolet light. GALEX picked out 30 elliptical and lens-shaped “early” galaxies with puzzlingly strong ultraviolet emissions but no signs of visible star formation, and Hubble was used to take a closer look.
What Hubble showed shocked the astronomers. Three-quarters of the galaxies were spanned by great, shining rings of ultraviolet light, with some ripples stretching 250,000 light-years. A few galaxies even had spiral-shaped ultraviolet features.
“We haven’t seen anything quite like these rings before,” said Michael Rich, co-author of the paper and a research astronomer at UCLA. “These beautiful and very unusual objects might be telling us something very important about the evolution of galaxies.”
But astronomers are unsure where the gas for this galactic resurrection came from and how it has created rings. One possibility is that a smaller galaxy merged with a big, old one, bringing in fresh gas to spawn hordes of new stars, and could in rare instances give rise to the ring structures as well.
But the researchers have their doubts about this origin scenario. “To create a density shock wave that forms rings like those we’ve seen, a small galaxy has to hit a larger galaxy pretty much straight in the center,” said Salim. “You have to have a dead-on collision, and that’s very uncommon.”
Another option that the astronomers like better is that the rejuvenating spark could have come from a gradual sopping-up of the gas in the so-called intergalactic medium, the thin soup of material between galaxies. This external gas could generate these rings, especially in the presence of bar-like structures that span some galaxies’ centers.
Ultimately, more observations will be needed to show how these galaxies began growing younger and lit up with humongous halos. Salim and Rich plan to search for more evidence of bars, as well as faint structures that might be the remnants of stellar blooms that occurred in the galaxies’ pasts. Rather like recurring seasons, it may be that galaxies stirred from winter can breed stars again and then bask in another vibrant, ultraviolet-soaked summer.
The study detailing the findings appeared in the April 21 issue of the Astrophysical Journal.
