Tag: Hubble

A galaxy slowly being eaten by its black hole

10:16 am

Spiral galaxy
Click for full image.

Cool image time! The photo to the right, rotated and reduced to post here, was taken by the Hubble Space Telescope. From the caption:

NGC 5495, which lies around 300 million light-years from Earth in the constellation Hydra, is a Seyfert galaxy, a type of galaxy with a particularly bright central region. These luminous cores — known to astronomers as active galactic nuclei — are dominated by the light emitted by dust and gas falling into a supermassive black hole. This image is drawn from a series of observations captured by astronomers studying supermassive black holes lurking in the hearts of other galaxies.

Essentially Seyfert galaxies are galaxies whose central supermassive black hole has become dominant, large enough that its gravity is slowly eating up the rest of the galaxy. As it increasingly swallows stars and gas, the black hole emits more and more energy, thus becoming an active galactic nuclei.

Two stars from our own galaxy also dominate this picture, one inside and to the right of the galaxy’s center, and the other the bright star at the bottom of the picture, both identified by the diffraction spikes.

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Interstellar clouds backlit by nearby massive star

1:27 pm

Interstellar clouds backlit by nearby massive star
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Cool image time! The photo to the right, cropped and reduce to post here, was taken by the Hubble Space Telescope of what astronomers believe is a newly formed massive star about 9,000 light years away that has periodically spewed out material during eruptions.

The scientists hope to use Hubble to determine the speed in which this material is flying away from the star by taking pictures at intervals and then measuring the amount of change from image to image. This data will also allow the scientists to better gauge the distance to this star, as well as its actual mass, information that will help them better understand what is happening.

I highlight this picture however simply because of its beauty. The interstellar clouds on the left are all apparently backlit by the brightest star on the right, and thus their shape is easy to perceive.

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A pair of spiral galaxies

2:02 pm

IC 4271, or AP 40, a pair of active galaxies
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Another cool image to herald in the weekend! The photo to the right, cropped and reduced to post here, was taken by the Hubble Space Telescope and shows a pair of spiral galaxies about 800 million light years away.

The smaller galaxy is superimposed on the larger one, which is a type of active galaxy called a Seyfert galaxy.

Seyfert galaxies are named for astronomer Carl K. Seyfert who, in 1943, published a paper about spiral galaxies with very bright emission lines. Today we know that about 10% of all galaxies may be Seyfert galaxies. They belong to the class of “active galaxies” – galaxies that have supermassive black holes at their centers accreting material, which releases vast amounts of radiation. The active cores of Seyfert galaxies are at their brightest when observed in light outside the visible spectrum. The larger galaxy in this pair is a Type II Seyfert galaxy, which means it is a very bright source of infrared and visible light.

In other words, both of these galaxies emit a lot of radiation in the infrared, radio, and X-rays due to activity taking place at the supermassive black holes believed to be at their cores.

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Colliding galaxies

1:11 pm

Merging galaxies

The string of amazing galaxy images coming from the Hubble Space Telescope continues. The photo to the right, cropped and reduced to post here, was released today and shows an object dubbed VV-689 that is believed to be two galaxies in the process of colliding and merging.

The angelic image comes from a set of Hubble observations that took a closer look at “Zoo Gems,” interesting galaxies from the Galaxy Zoo citizen science project. This crowdsourced program relies on hundreds of thousands of volunteers to classify galaxies and help astronomers wade through a deluge of data from robotic telescopes. In the process, volunteers discovered a gallery of weird and wonderful galaxy types, some not previously studied.

This image will lay the groundwork for more detailed research. Right now it appears no one has even estimated its distance.

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The spiral galaxy M91

3:38 pm

spiral galaxy M91
Click for full release image.

Cool image time! The image to the right, reduced to post here, was released today by the Space Telescope Science Institute as part of a regular program using the Hubble Space Telescope to photograph galaxies.

This observation is part of an effort to build a treasure trove of astronomical data exploring the connections between young stars and the clouds of cold gas in which they form. To do this, astronomers used Hubble to obtain ultraviolet and visible observations of galaxies already seen at radio wavelengths by the ground-based Atacama Large Millimeter/submillimeter Array.

The galaxy is estimated to be about 55 million light years away, and is thought to have a supermassive black hole at its center with a mass somewhere between 9 and 38 million times the mass of the Sun.

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Hugging galaxies

2:25 pm

Hugging galaxies
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Cool image time! The Hubble Space Telescope science team today released the photo to the right, cropped and reduced to post here, of the interaction of three galaxies, the larger two of which look like they are hugging each other.

This galaxy triplet is estimated to be about just under 700 million light years away. It was taken as part of a program aimed at producing high quality images of strange looking galaxies.

Using Hubble’s powerful Advanced Camera for Surveys, astronomers took a closer look at some of the more unusual galaxies that volunteers identified. The original Galaxy Zoo project was the largest galaxy census ever carried out and relied on crowdsourcing time from more than 100,000 volunteers to classify 900,000 unexamined galaxies. The project achieved what would have been years of work for a professional astronomer in only 175 days and has led to a steady stream of similar astronomical citizen science projects. Later Galaxy Zoo projects have included the largest ever studies of galaxy mergers and tidal dwarf galaxies, as well as the discovery of entirely new types of compact star-forming galaxies.

If you want to do some real science, you should definitely check out the Galaxy Zoo webpage. Anyone can join in, using images produced by the Victor Blanco 156 inch (4 meter) telescope in Chile to find cool stuff that needs closer examination using better telescopes like Hubble.

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A galactic starship Enterprise

3:30 pm

A galactic starship Enterprise
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Cool image time! The image to the right, cropped and reduced to post here, was taken by cameras on the Hubble Space Telescope. From the caption:

The subject of this image is a group of three galaxies, collectively known as NGC 7764A. They were imaged by the NASA/ESA Hubble Space Telescope, using both its Advanced Camera for Surveys and Wide Field Camera 3. The two galaxies in the upper right of the image appear to be interacting with one another. The long trails of stars and gas extending from them give the impression that they have both just been struck at great speed, thrown into disarray by the bowling-ball-shaped galaxy to the lower left of the image. In reality, interactions between galaxies happen over very long time periods, and galaxies rarely collide head-on with one another. It is also unclear whether the galaxy to the lower left is interacting with the other two, although they are so relatively close in space that it seems possible that they are.

This galaxy group is estimated to be about 425 million light years away, though that number might be different for the galaxy in the lower left.

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Hubble resumes full science operations

2:35 pm

Engineers have now successfully reactivated the Hubble Space Telescope’s second spectrograph, so that the telescope is now fully operational for the first time since it went into safe mode on October 25th.

NASA’s Hubble Space Telescope team recovered the Space Telescope Imaging Spectrograph on Monday, Dec. 6, and is now operating with all four active instruments collecting science. The team has still not detected any further synchronization message issues since monitoring began Nov. 1.

The team will continue work on developing and testing changes to instrument software that would allow them to conduct science operations even if they encounter several lost synchronization messages in the future. The first of these changes is scheduled to be installed on the Cosmic Origins Spectrograph in mid-December. The other instruments will receive similar updates in the coming months.

Essentially, they are modifying the telescope’s software so that it will not shut down should it “encounter several lost synchronization messages.” As the engineers have never fully explained this issue, I suspect this is a work-around to ignore an issue that in the past they would have taken more seriously. Now they are doing a cost-benefit analysis, and have decided that ignoring some of these messages is better than fixing them. It might even be impossible to do so.

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Engineers recover a third Hubble instrument

2:39 pm

Engineers have now reactivated a third instrument on the Hubble Space Telescope, bringing the telescope very close to full operations again with only one instrument, a spectrograph, still in safe mode.

The Hubble Space Telescope team recovered the Cosmic Origins Spectrograph instrument on Sunday, Nov. 28, moving the telescope further toward full science operations. Three of Hubble’s four active instruments are now collecting science data once again.

The team also continued work on developing and testing changes to instrument software that would allow them to conduct science operations even if they encounter several lost synchronization messages in the future. Those changes would first be installed on the Cosmic Origins Spectrograph once they’re completed and tested within a few weeks. Hubble’s other instruments would also receive similar changes. The team has not detected further synchronization message issues since monitoring began Nov. 1.

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Hubble camera back in operation

2:16 pm

Good news! As engineers work to fix the problem that caused the Hubble Space Telescope to shut down on October 25th, they have now successfully returned Hubble’s most important camera back to doing science.

The Hubble team successfully recovered the Advanced Camera for Surveys instrument Nov. 7. The instrument has started taking science observations once again. Hubble’s other instruments remain in safe mode while NASA continues investigating the lost synchronization messages first detected Oct. 23. The camera was selected as the first instrument to recover as it faces the fewest complications should a lost message occur.

This success strongly suggests they have pinpointed the software issue that caused the shutdown, and can now step-by-step reactivate all the other instruments in the coming week.

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1st water vapor in Ganymede’s atmosphere, detected using data from Hubble

9:06 am

Using Hubble data, astronomers have detected the first evidence of water vapor in the atmosphere of Jupiter’s largest moon, Ganymede.

Though larger than the blistering planet Mercury, the Jovian moon Ganymede is no place to go sunbathing. Located ½-billion miles from the Sun, the water ice on its surface is frozen solid in frigid temperatures as low as minus 300 degrees Fahrenheit. This makes the ice as hard as rock. Still, a rain of charged particles from the Sun is enough to turn the ice into water vapor at high noon on Ganymede.

This is the first time such evidence has been found, courtesy of the Hubble Space Telescope’s spectroscopic observations of aurora on Ganymede spanning two decades. The auroras are used to trace the presence of oxygen, which then is linked to the presence of water molecules sputtering off the surface. Ganymede has a deep ocean located an estimated 100 miles below the surface. That’s too deep for water vapor to be leaking out.

This detection has a margin of uncertainty, but it provides a baseline for the up close observations planned for Europe’s JUICE orbiter, set to launch in ’22 and arrive in Jupiter orbit in ’29. JUICE’s study focus will be the three Galilean moons that appear to have lots of ice, Ganymede, Calisto, and Europa.

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Hubble returned to science operations

8:49 am

Engineers today completed their testing of their computer hardware fix on the Hubble Space Telescope and took it out of safe mode, allowing science observations to resume after more than a month.

The first observation is scheduled for Saturday afternoon after some instrument calibrations are completed. Most observations missed while science operations were suspended will be rescheduled for a later date.

Now let us all pray that there are no more major failures for the next few years until the U.S. capabilities in space grow and a relatively fast mission to repair the telescope is possible.

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Engineers report Hubble fix appears successfully

8:50 am

Engineers this morning announced that their attempt to switch to backup computer hardware on the Hubble Space Telescope was successful.

The switch included bringing online the backup Power Control Unit (PCU) and the backup Command Unit/Science Data Formatter (CU/SDF) on the other side of the Science Instrument and Command & Data Handling (SI C&DH) unit. The PCU distributes power to the SI C&DH components, and the CU/SDF sends and formats commands and data. In addition, other pieces of hardware onboard Hubble were switched to their alternate interfaces to connect to this backup side of the SI C&DH. Once these steps were completed, the backup payload computer on this same unit was turned on and loaded with flight software and brought up to normal operations mode.

They are now doing tests to make sure everything is working as expected, and preparing the telescope to bring it out of safe mode and resume science operations.

This is great news, but to bring everyone down to Earth, we must remember that Hubble no longer has any redundancy in this area. Should there be another similar computer failure, the telescope will then be dead in the water, with the only way to bring it back a manned or robotic mission — something we presently do not have the capacity to do — to replace these units.

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Hubble update: Engineers pinpoint issue, prepare to fix it

12:38 pm

In an update today on the status for bringing the Hubble Space Telescope back into science operations, the engineers say they think they have pinpointed the failed unit, and are ready to do the switch to a backup.

A series of multi-day tests, which included attempts to restart and reconfigure the computer and the backup computer, were not successful, but the information gathered from those activities has led the Hubble team to determine that the possible cause of the problem is in the Power Control Unit (PCU).

The PCU also resides on the SI C&DH unit. It ensures a steady voltage supply to the payload computer’s hardware. The PCU contains a power regulator that provides a constant five volts of electricity to the payload computer and its memory. A secondary protection circuit senses the voltage levels leaving the power regulator. If the voltage falls below or exceeds allowable levels, this secondary circuit tells the payload computer that it should cease operations. The team’s analysis suggests that either the voltage level from the regulator is outside of acceptable levels (thereby tripping the secondary protection circuit), or the secondary protection circuit has degraded over time and is stuck in this inhibit state.

Because no ground commands were able to reset the PCU, the Hubble team will be switching over to the backup side of the SI C&DH unit that contains the backup PCU. All testing of procedures for the switch and associated reviews have been completed, and NASA management has given approval to proceed. The switch will begin Thursday, July 15, and, if successful, it will take several days to completely return the observatory to normal science operations.

Engineers did a similar switch in 2008, so they are very confident it will work this time also. However, once done, the telescope will no longer have backups for any of these computer modules. The next failure in any of them will shut the telescope down, for good.

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Engineers successful complete simulation of Hubble repair

12:30 pm

Though the details released are sparse, engineers working to get the Hubble Space Telescope back in operation since it shut down due to a computer problem in mid-June report today that they have successfully completed a simulation of the procedures they need to do to fix the problem.

This is their entire report:

[The engineers] successfully completed a test of procedures that would be used to switch to backup hardware on Hubble in response to the payload computer problem. This switch could occur next week after further preparations and reviews.

Apparently, because the switch to backup hardware requires switching more than one unit, the sequence is important and following it correctly is critical. It appears they have now determined the correct sequence and will attempt it on Hubble next week.

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Hubble update: Engineers narrow possible failed hardware to one of two units

5:09 pm

Engineers working to pinpoint the cause of the computer hardware issue that has placed the Hubble Space Telescope in safe mode since June 13th have now narrowed the possible failed hardware to one of two units.

The source of the computer problem lies in the Science Instrument Command and Data Handling (SI C&DH) unit, where the payload computer resides. A few hardware pieces on the SI C&DH could be the culprit(s).

The team is currently scrutinizing the Command Unit/Science Data Formatter (CU/SDF), which sends and formats commands and data. They are also looking at a power regulator within the Power Control Unit, which is designed to ensure a steady voltage supply to the payload computer’s hardware. If one of these systems is determined to be the likely cause, the team must complete a more complicated operations procedure to switch to the backup units. This procedure would be more complex and riskier than those the team executed last week, which involved switching to the backup payload computer hardware and memory modules. To switch to the backup CU/SDF or power regulator, several other hardware boxes on the spacecraft must also be switched due to the way they are connected to the SI C&DH unit.

Over the next week or so, the team will review and update all of the operations procedures, commands and other related items necessary to perform the switch to backup hardware. They will then test their execution against a high-fidelity simulator.

The team performed a similar switch in 2008, which allowed Hubble to continue normal science operations after a CU/SDF module failed.

That such a switch was done successfully in the past is a very hopeful sign. However, it sounds as though they are not 100% sure they have pinpointed the actual issue, which means that this switch still might not fix the problem.

We can only wait and hope. And even if the fix works, Hubble will no longer have working backup units for these pieces of hardware. Should any of the backup that are now being activated fail, the telescope will fail, and this time it won’t be fixable with the equipment on board.

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Hubble update: Still no solution

2:02 pm

An update today from the engineers trouble-shooting the problem on the Hubble Space Telescope that put it into safe mode on June 13 continue to show the problem is complex, and has not yet been traced to its source.

Additional tests performed on June 23 and 24 included turning on the backup computer for the first time in space. The tests showed that numerous combinations of [a number of] hardware pieces from both the primary and backup payload computer all experienced the same error – commands to write into or read from memory were not successful.

Since it is highly unlikely that all individual hardware elements have a problem, the team is now looking at other hardware as the possible culprit, including the Command Unit/Science Data Formatter (CU/SDF), another module on the SI C&DH [the module that holds the telescope’s computers]. The CU formats and sends commands and data to specific destinations, including the science instruments. The SDF formats the science data from the science instruments for transmission to the ground. The team is also looking at the power regulator to see if possibly the voltages being supplied to hardware are not what they should be. A power regulator ensures a steady constant voltage supply. If the voltage is out of limits, it could cause the problems observed.

They remain hopeful they can find the problem and fix it, though the longer it takes the more worrisome it becomes.

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Update on attempts to bring Hubble back to life

4:26 pm

Engineers have released an update on their attempts to bring Hubble out of safe mode that are indicating that they are honing in on the cause of the problem.

After performing tests on several of the computer’s memory modules, the results indicate that a different piece of computer hardware may have caused the problem, with the memory errors being only a symptom. The operations team is investigating whether the Standard Interface (STINT) hardware, which bridges communications between the computer’s Central Processing Module (CPM) and other components, or the CPM itself is responsible for the issue. The team is currently designing tests that will be run in the next few days to attempt to further isolate the problem and identify a potential solution.

This step is important for determining what hardware is still working properly for future reference. If the problem with the payload computer can’t be fixed, the operations team will be prepared to switch to the STINT and CPM hardware onboard the backup payload computer. The team has conducted ground tests and operations procedure reviews to verify all the commanding required to perform that switch on the spacecraft.

It appears that no matter what solution they arrive at, they will still require several days to test the solution to make sure it works. This update however is very hopeful, as it does appear they are locating the cause and have avenues for fixing it.

Hubble went into safe mode on June 13, which means it has now been out of operation for more than ten days.

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New Hubble images of Uranus and Neptune

9:28 am

Uranus (top) and Neptune

The Hubble Space Telescope’s new annual images of Uranus (top) and Neptune (bottom) has revealed new atmospheric features for both, a giant north pole cloud cap on Uranus and a new dark storm developing on Neptune.

For Neptune:

The new Hubble view of Neptune shows the dark storm, seen at top center. Appearing during the planet’s southern summer, the feature is the fourth and latest mysterious dark vortex captured by Hubble since 1993. Two other dark storms were discovered by the Voyager 2 spacecraft in 1989 as it flew by the remote planet. Since then, only Hubble has had the sensitivity in blue light to track these elusive features, which have appeared and faded quickly. A study led by University of California, Berkeley, undergraduate student Andrew Hsu estimated that the dark spots appear every four to six years at different latitudes and disappear after about two years.

Hubble uncovered the latest storm in September 2018 in Neptune’s northern hemisphere. The feature is roughly 6,800 miles across.

For Uranus:

The snapshot of Uranus, like the image of Neptune, reveals a dominant feature: a vast bright cloud cap across the north pole.

Scientists believe this feature is a result of Uranus’ unique rotation. Unlike every other planet in the solar system, Uranus is tipped over almost onto its side. Because of this extreme tilt, during the planet’s summer the Sun shines almost directly onto the north pole and never sets. Uranus is now approaching the middle of its summer season, and the polar-cap region is becoming more prominent. This polar hood may have formed by seasonal changes in atmospheric flow.

The images are part of an annual program that monitors both planets with images every year when the Earth is best placed to view them. This allows scientists to track atmospheric changes over time.

The sharpness of both images matches that of previous Hubble images, so these photographs do not show any decline in the telescope’s image capability. However, when they lose that next gyroscope and shift to one gyroscope mode, I believe it will be very difficult to get images even this sharp of the outer planets. In fact, I suspect this monitoring program will likely have to end, or will be badly crippled.

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A Hubble Space Telescope status report

4:48 pm

Five years after the last shuttle repair mission, the Hubble Space Telescope continues to operate almost perfectly.

Jeletic said other than a single gyro failure, the observatory is operating in near-flawless fashion five years after the final shuttle crew departed. “Batteries are fine, solar arrays are fine, all the communications equipment is fine, we don’t see any glitches with the computers, the instruments are all fine,” he said. “In fact, an interesting statistic, the Advanced Camera for Surveys, which was repaired by the astronauts during the last servicing mission, that’s actually now run longer on the repair than it did originally for the Wide Field Camera part of it.”

The ACS, like the repaired Space Telescope Imaging Spectrograph, no longer has any internal redundancy. “It’s amazing. It truly is,” Jeletic said. “Given all the things that can fail, a lot of people were hoping for one or two years of continued work with it. Now we’ve gotten over five.” Likewise, the Space Telescope Imaging Spectrograph, which also is operating in “single-string” mode, is still going strong.

When they completed the 2009 servicing mission, the goal was to give Hubble five more years of operation. They’ve done that, and are now looking to keep the telescope going till at least 2020, marking 30 years in orbit.

The only issue, not surprisingly, is the failure of one of the six gyros on board. These have traditionally been the telescope’s biggest problem, and have been replaced twice over during shuttle missions. Three of today’s six however are using a new design which will hopefully extend their life significantly.

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Exoplanets with no water

6:43 pm

The uncertainty of science: Though planet formation theories said they should have water, in looking for water on three exoplanets astronomers were surprised to discover practically none there.

The three planets, known as HD 189733b, HD 209458b, and WASP-12b, are between 60 and 900 light-years away from Earth and were thought to be ideal candidates for detecting water vapor in their atmospheres because of their high temperatures where water turns into a measurable vapor. These so-called “hot Jupiters” are so close to their star they have temperatures between 1,500 and 4,000 degrees Fahrenheit, however, the planets were found to have only one-tenth to one one-thousandth the amount of water predicted by standard planet-formation theories.

“Our water measurement in one of the planets, HD 209458b, is the highest-precision measurement of any chemical compound in a planet outside our solar system, and we can now say with much greater certainty than ever before that we’ve found water in an exoplanet,” said Nikku Madhusudhan of the Institute of Astronomy at the University of Cambridge, England. “However, the low water abundance we have found so far is quite astonishing.” Madhusudhan, who led the research, said that this finding presents a major challenge to exoplanet theory. “It basically opens a whole can of worms in planet formation. We expected all these planets to have lots of water in them. We have to revisit planet formation and migration models of giant planets, especially “hot Jupiters,” and investigate how they’re formed.”

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As imagined by SF authors: the Celestial Spiral

2:30 pm

This amazing Hubble image, showing a strange spiral to the left of the bright star, is not of a galaxy. Instead, it is a binary star system where the material from one star is being sucked away from it by the other, thus producing the spiral pattern.

celestial spiral

What is most fascinating about this discovery is that this kind of phenomenon has been predicted for decades, by both astronomers and science fiction writers. Consider for example this quote from Larry Niven from his short story, The Soft Weapon, where he describes what he thinks the binary star Beta Lyrae might look like:

There was smoke across the sky, a trail of red smoke wound in a tight spiral coil. At the center of the coil was the source of the fire: a double star. One member was violet-white, a flame to brand holes in a human retina, its force held in check by the polarized window. The companion was small and yellow. They seemed to burn inches apart, so close that their masses had pulled them both into flattened eggs, so close that a red belt of lesser flame looped around them to link their bulging equators togehter. The belt was hydrogen, still mating in fusion fire, pulled loose from the stellar surfaces by two gravitional wells in conflict.

The gravity did more than that. It sent a loose end of the red belt flailing away, away and out in a burning Maypole spiral that expanded and dimmed as it rose toward interstellar space, until it turned from flame-red to smoke-red, bracketing the sky and painting a spiral path of stars deep red across half the universe.

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Hubble image of face-on galaxy

10:10 pm

Another spectacular Hubble Space Telescope image was released today, showing a face-on spiral galaxy in the Coma cluster, located about 320 million light years away. Key quote:

The galaxy, known as NGC 4911, contains rich lanes of dust and gas near its center. These are silhouetted against glowing newborn star clusters and iridescent pink clouds of hydrogen, the existence of which indicates ongoing star formation. Hubble has also captured the outer spiral arms of NGC 4911, along with thousands of other galaxies of varying sizes.

NGC 4911

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