National Geographic Daily News
Illustration of supernova magnification.

This schematic illustration shows the magnification of a supernova by gravitational lensing.

Illustration by Aya Tsuboi, Kavli IPMU

Nadia Drake

for National Geographic

Published April 24, 2014

A supernova that exploded in 2010 and that appeared to burn much brighter than a normal star explosion is explained by the presence of a giant cosmic magnifying lens, scientists announced Thursday.

The four-year-old star explosion, known as supernova PS1-10afx, had confounded scientists because it was 30 times brighter than normal.

On Thursday, a team of scientists announced that a nearby galaxy's gravity had made the supernova appear superbright.

Writing in the the journal Science, the team said that when cosmic objects align with one right in front of the other, the foreground object's gravity can act as a lens, warping and magnifying the background object's light.

"This has been a huge mystery," says astronomer Andy Howell of Las Cumbres Observatory Global Telescope Network. "But this new work makes a compelling case that this is a type 1a supernova that has been gravitationally lensed."

PS1-10afx has perplexed scientists ever since its discovery by the Hawaii-based Pan-STARRS1 telescope. Like all type 1a supernovae, the explosion resulted from a thermonuclear detonation that ripped apart a white dwarf star. Normally, these blasts shine with a predictable brightness, which is why scientists use them as cosmic distance markers.

But PS1-10afx, which in all other respects looked a lot like a type 1a, was way too bright—30 times brighter than it should have been.

Looking for Explanations

Teams trying to explain the peculiar supernova offered two different explanations. One team suggested that PS1-10afx might belong to a grab bag of blinding stellar oddities known as superluminous supernovas that are ten to a hundred times brighter than normal. A few weeks later, another team suggested it was a magnified, normal type 1a.

"We have good reason to believe that [type 1a supernovae] can't get as bright as PS1-10afx—or that if they did, they would look completely different," says study author Robert Quimby, an astronomer at the Kavli Institute for the Physics and Mathematics of the Universe, near Tokyo. "I thought it had to be gravitationally lensed."

The trouble was, there was no lens in sight.

Late last year, after the supernova had dimmed, Quimby and his colleagues set out to find the missing lens. They aimed the Hawaii-based Keck 1 telescope at the explosion site for 6.5 hours, searching for emission lines that would tell them whether they were seeing one galaxy or two. When the spectra came back, the team had their answer: In the foreground, about 8.2 billion light-years away, is a little galaxy. Much smaller than the Milky Way, it has an observed mass equivalent to about ten billion suns.

In the background? The supernova's host galaxy, sitting about nine billion light-years from Earth.

"I think it's time to throw in the towel on the idea that it was a different type of supernova and admit that there's evidence for a lens," says Robert Kirshner of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts.

"Nature's Microscope"

Still, some astronomers would like to see stronger evidence for the foreground galaxy—chiefly, more emission lines or a clear Hubble Space Telescope image of the region, which Quimby is working on.

"They have a reasonably strong case that there are two galaxies there," says Saurabh Jha, an astrophysicist at Rutgers University in Piscataway, New Jersey. Jha and others are also curious about what the foreground galaxy's total mass is—that is, the mass of both visible matter and dark matter, the mysterious material that cannot be seen yet still exerts gravitational force.

PS1-10afx is not the only known lensed supernova. There are at least three other recent observations, detected by the CLASH survey, of supernovae magnified by entire galaxy clusters.

"One of the great things about gravitational lensing is that it makes things visible that we wouldn't have been able to see," Jha says. "You wouldn't have been able to see this supernova from the ground except that it got so much brighter with lensing."

In extreme cases, gravitational lensing can produce multiple images of the background object. Depending on the path they take through the cosmos, these images can be seen on Earth at different times. That difference in arrival time could help astronomers measure the Hubble constant, or the rate at which the universe is expanding. Lensed supernovae could also help astronomers probe the distant, dark universe by making it possible to calculate the amount of dark matter in a cosmic lens.

"You have nature's microscope out there, in the form of these gravitational lenses," Kirshner says. "It opens the window to seeing things at much greater distances than we could do otherwise."

Follow Nadia Drake on Twitter.

Chris Colby
Chris Colby

I am wondering: I light of a past article about the possibility of small "black holes" wandering our galaxy...would not their "lensing " capabilities not only reveal their locations...but also magnify the are's behind them??  Namaste!  :)

Omar Aboelfetouh
Omar Aboelfetouh

" So I swear by the retreating stars - {15}

Those that run [their courses] and disappear - {16} "

At-Takwīr - Holy Qur'an

Actually the verse is literally translated .. the verse 16 describes these stars as

1- "" Runners _in their courses _ ""
2- "" Sweepers - sweep everything in their way " ""

Omar Aboelfetouh
Omar Aboelfetouh

↓ These verses are there in the Holy Quran since more than 1400 years . read carefully and get your mind blown  


" And the sky We constructed with strength, and indeed, We are [its] expander "

Adh-Dhāriyāt 47 Holy Quran

" Then I swear by (( the setting)) of the stars {75}
And indeed, it is an oath - if you could know - [most] great{76}
Indeed, it is a noble Qur'an {77} In a Register well-protected {78}
None touch it except the purified {79}
[It is] a revelation from the Lord of the worlds {80}
Then is it to this statement that you are indifferent ! {81} "

Al-Wāqi`ah - Holy Quran


" So I swear by the retreating stars - {15}
Those that run [their courses] and disappear - {16} "

At-Takwīr - Holy Quran

Billy Slusser
Billy Slusser

What is the maximum life span of any living thing in this universe ? Anyone know ? That life span for that particular life would grow longer in the future wouldn't it ? What is the probability that computers were invented in the past on another planet ? Is our technology transparently given to us or is it the natural course of life here to do what we are doing ? So hypothetically speaking, there is life in this universe with longer life spans than our own, with better technology. What do they think about us ?

Moti Gupta
Moti Gupta

Its a great job. I believe this theory of lensing by gravitational pull shall open many unsolved mysteries of universe expansion and also about dark matter.

Conrad Wang
Conrad Wang

Years ago people were talking about distorting the space so we can travel through it faster like a worm hole; but that was just a misconception that distortion of light was some how linked to the distortion of physical space as demonstrated here in the "super bright super nova"

Robert R.
Robert R.

"that is, the mass of both visible matter and dark matter, the mysterious material that cannot be seen yet still exerts gravitational force" - Does this mean that in some instances stars, galaxies, or whatnot, may not be as far away as we think they are or further away (because if gravity can become more dense I assume it can also become less dense)? How does this affect our ability to judge distances in space? If gravity can become inconstant distances would appear to vary wouldn't they? How do you guage the variance?

arjun son
arjun son

@Omar Aboelfetouh  this is science not a religion

Edgard Jacobs
Edgard Jacobs

@Billy Slusser Based on the age of the universe and the sheer number of planets in it, it's pretty likely that life occurred before us. Beyond that, there's too little information to speculate.

Wyn Easton
Wyn Easton

Gravity warps space-time. The shortest distance between two point is a straight line. In reality, the shortest distance a photon can travel is the one that reaches our eye that traveled with the least warping.

Omar Aboelfetouh
Omar Aboelfetouh

@Pavle Marinkovic @Omar Aboelfetouh

Hey chill ! :D

I'm not saying that these verses relate .. All I'm saying is that some facts and discoveries that were discovered in the 20th century  have been actually mentioned in the Holy Qur'an since more than 1400 years

such as

1- The Expansion of the Universe 

2- Supernovas

3- Black holes 

***** There are some other things that haven't been discovered or proven scientifically yet that were mentioned in the Holy Qur'an *****

OF COURSE Qur'an isn't a science book . and of course not all scientific facts are mentioned . but some facts are mentioned as a proof that this book is coming from the creator of this universe who knows it better than anyone of his creatures .

at least if you don't believe it , just don't ignore it . Study and discuss because you want to know not because you want to disagree .

peace be upon all .


How to Feed Our Growing Planet

  • Feed the World

    Feed the World

    National Geographic explores how we can feed the growing population without overwhelming the planet in our food series.

See blogs, stories, photos, and news »

The Innovators Project

See more innovators »

Latest News Video

See more videos »

See Us on Google Glass

Shop Our Space Collection

  • Be the First to Own <i>Cosmos: A Spacetime Odyssey</i>

    Be the First to Own Cosmos: A Spacetime Odyssey

    The updated companion book to Carl Sagan's Cosmos, featuring a new forward by Neil deGrasse Tyson is now available. Proceeds support our mission programs, which protect species, habitats, and cultures.

Shop Now »