Hubble Sees a Double Einstein Ring

by Fraser Cain on January 10, 2008

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Einstein Ring. Image credit: Hubble
An Einstein Ring happens when two galaxies are perfectly aligned. The closer galaxy acts as a lens, magnifying and distorting the view of a more distant galaxy. But today astronomers announced that they’ve discovered a double Einstein Ring: three galaxies are perfectly aligned, creating a double ring around the lensing galaxy. The odds of finding something like this are pretty low. And yet… here it is.

The double Einstein Ring image was captured by the Hubble Space Telescope, and shows a central galaxy surrounding by an almost complete ring, with another fainter ring around that. Think of a bull’s-eye.

It was found by an international team of astronomers led by Raphael Gavazzi and Tommaso Treu of the University of California, Santa Barbara, and the results were presented at the 211th meeting of the American Astronomical Society in Austin, Texas.

Treu was pretty excited, “the twin rings were clearly visible in the Hubble image. When I first saw it I said ‘wow, this is insane!’ I could not believe it!”

Here’s how it works. As Einstein predicted, gravity has the power to bend light. So instead of traveling on a straight curve, light that passes close to a large mass is pulled into a curved path. When you have a foreground galaxy perfectly lined up with a background galaxy, the light from the more distant galaxy is distorted into a ring of light.

Although the background galaxy is distorted, it’s also tremendously magnified, allowing astronomers to use the foreground galaxy as a natural telescope to peer much more deeply into the Universe than they would be able to see normally.

In the case of this double ring, the foreground galaxy is 3 billion light-years away. The background galaxy that forms the first ring is 6 billion light-years away, and the second background galaxy is 11 billion-light years away. This means that the background galaxy is being seen when the Universe was less than 3 billion years old.

The alignment also allowed astronomers to measure the mass of the middle galaxy to 1 billion solar masses. This is the first time the mass of a dwarf galaxy has been measured at this kind of distance.

Original Source: Hubble News Release

About 

Fraser Cain is the publisher of Universe Today. He's also the co-host of Astronomy Cast with Dr. Pamela Gay.

Peter K January 10, 2008 at 12:21 PM

Aren’t all your numbers one off? If we can see two galaxies, one behind the other, then that is THREE galaxies perfectly lined up, one being our own. In this case it would be FOUR!
Even MORE impressive!

Nik January 10, 2008 at 5:00 PM

Wait… so if the furthest galaxy is 11 billion light years away, doesnt that mean that said “perfect alignment” was actually billions of years ago too?

(Yes i know light year is a measurement of distance and not of time, but if the light from that galaxy takes 11 billion years to reach us, then what we are seeing must be the way it was 11 billion years ago…)

Paul Santos January 10, 2008 at 5:01 PM

It’s a Web 2.0 logo!

Geoff Offenhuber January 10, 2008 at 5:30 PM

I hate it when they fabricate stories like this…but I guess its the only way they can keep funding coming in. Obviously, its a Photoshop filter.

Kearn Kirkwood January 10, 2008 at 5:34 PM

Actually, isn’t it one step weirder than that? Since the light had to travel for billions of years between each galaxy, wouldn’t that mean that there was never one moment in time that they were all perfectly physically aligned? The light left the first galaxy, 11 billion years ago, 5 billions years later it went past the next galaxy, 3 billion years later it swung past the next one (by that point the first two probably had moved and were not aligned with the third), and then 3 billion years later, this twice bent light hits the Hubble, by which point no three (much less all four counting us) of the galaxies are actually in the same line. Just shear random coincidence that this light cruising through space happened to bend past 2 galaxies before hitting ours. And, since we’re on the outer edge of our galaxy, isn’t there a chance some of the light missed us, got bent again, and is going to hit some other galaxy in a few billion more years, with us magnifying the first galaxy even more, creating a triple Einstein ring for them?

Noah January 10, 2008 at 5:45 PM

Well, this is absolutely uncanny.

Does anyone know what the numerical odds are?

Freiddie January 10, 2008 at 6:10 PM

I like the picture, looks like one that came from a galactic hall of mirrors.

Geoff Offenhuber January 10, 2008 at 9:20 PM

Glad you agree with me Kearn! I hope NASA will stop wasting our time with these wild statements and get back to developing spy satellites to protect our nation’s security.

Tom January 11, 2008 at 6:37 AM

So…let me get this straight. We’re accusing NASA and the Hubble imaging teams of fabricating this image for…wait….what would they have to gain from a waste of time like that?

Perhaps they made this image in the same super-secret area they faked the moon landing.

The Challenger and Columbia disasters never happened, and we’ve secretly had alien representation in the UN for 50 years now.

Yeah…they faked the image. You must be right. About as right as thinking that NASA (and not the military, specifically the US Air Force) are responsible for the design of spy satellites.

I just want to thank you for opening my eyes! I think what was really behind this “faked” image was the pearly gates of heaven, and the government, in part with their secret alliance with the Vatican and the aliens, had to keep this discovery from the public. I mean, we couldn’t have Branson offering to fly people to heaven, now could we?

Noah – FYI, I don’t know the exact odds, but S&T described the chances as rare as winning by betting the same number twice in a row in roulettte.

(yes, I know that’s spelled wrong, but UT’s filters thought it was spam so I changed the spelling)

Geoff Offenhuber January 11, 2008 at 8:21 AM

The thing you have to remember Tom, is that NASA and Hubble are not around to take pretty pictures of distant galaxies or to grow mold in zero gravity. They are used for national security. Such as the Hubble being used to monitor our boarders for illegal immigrants. Occasionally, they have to release items like this fantasy to keep the public happy allowing the government the opportunity to keep funding the program.

Tom January 11, 2008 at 9:48 AM

Doesn’t using the most powerful (in the visual spectrum, anyway) telescope in space to watch illegals hopping the border seem like a bit of overkill?

I think the sheer volume of reflected light coming from the Earth would simply overwhelm Hubble’s optics if it were to be pointed at our planet, as Hubble’s visual spectrum instrumentation is highly sensitive, and intented (by design) to view light from very far off sources.

Even if that were not the case, it is my understanding that Hubble cannot orient itself to face the Earth…or if it can it at least does not do so.

I checked the upcoming schedule for the HST, and I don’t see any terrestrial observations on that schedule. Actually, contrary to your statement, it would seem that Hubble’s primary mission IS to take images (or pretty pictures) of far off galaxies, etc.

We have many, many satellites in orbit that are specifically designed to watch the Earth and those on it – monitored and run by various military and civillian intelligence agencies.

Even if we wanted Hubble to watch the Earth it would be unable to, as the visual instruments are currently damaged and are scheduled for repair in August of 2008. (it is my understanding that this affects HST’s ability to see visible light, but other instruments, like ultraviolet and x-ray arrays are still functional)

If HST was our only way to “keep our borders safe”, wouldn’t the government want to get the optics packages back to 100% a little faster than they are?

A few examles of upcoming scheduled time on the HST:

“Search for Extremely Faint z>7 Galaxy Population with Cosmic Lenses ”

“A Snapshot Survey of the Sites of Recent, Nearby Supernovae ”

“Dissecting An Accretion Disk”

“NICMOS Imaging of GOODS: Probing the Evolution of the Earliest Massive Galaxies, Galaxies Beyond Reionization, and the High Redshift Obscured Universe ”

“Probing Solar System History with Orbits, Masses, and Colors of Transneptunian Binaries ”

The list goes on and on.

Point here is that the HST’s mission and operating time has absolutely nothing to do with watching our border, and everything to do with discovering the mysteries of the universe.

rob January 11, 2008 at 10:42 AM

Can’t we just be amazed and awed by this without the homeland security gheyness? Swear to god right wingers see politics in everything and it is tiring. I find this imaging amazing. Wondering and pondering the universe and where we fit is way more profound and meaningful than this political BS.

raldes January 11, 2008 at 11:05 AM

i think it is more entertaining to view Geoff Offenhuber comments as ironic. makes them hilarious to read!

Niles January 11, 2008 at 11:27 AM

Is your name really Fraser Cane?

knewjet January 29, 2008 at 9:10 PM

So lets say about the double einstein ring, that like einstein’s daughter lieserl died ,or did she? Someone knows,and really think who einstein knows and what. The double einstein rings effect gravity that effect light, this is also what is happening to our galaxy, so our view is then very different from what we are seeing, even from short distances. Just like the example of the cat in the box whether it is alive or dead.The point is you have to know what your seeing that is fact in how slectromagnetic field and gravity works ,so you do have to know your stuff whether some thing is alive thought or dead thought from any point.

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