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Hubble discovers most distant galaxy ever observed

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November 16, 2012

Distant galaxy lensed by Cluster MACS J0647 (Image: NASA)

Distant galaxy lensed by Cluster MACS J0647 (Image: NASA)

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NASA's Hubble telescope has discovered the most distant object yet seen in the universe. The object, a galaxy called MACS0647-JD, is 13.3 billion light years from Earth and can only be seen with the help of a lens of intergalactic proportions. The light from MACS0647-JD left it only 420 million years after the Big Bang, so it provides a valuable look into the nature of the early universe.

MACS0647-JD was observed by the Hubble telescope, though not directly. It’s much too faint to be picked up by the orbiting observatory, so the image had to be magnified first. Between Earth and MACS0647-JD, at a distance from us of 5.6 billion light years, is a galactic cluster called MACS J0647+7015. This is made up largely of dark matter and is so massive that it bends light around itself and acts as a gravitational lens millions of light years in diameter. As the light from MACS0647-JD passed the cluster, it was magnified and split into three images - MACS0647-JD1, MACS0647-JD2 and MACS0647-JD3. These images were two to eight times brighter than the original.

Cluster MACS J0647+7015 and three magnified views of distant galaxy (Image: NASA)
Cluster MACS J0647+7015 and three magnified views of distant galaxy (Image: NASA)

MACS0647-JD was found as part of the Cluster Lensing And Supernova Survey with Hubble (CLASH), an international group led by Marc Postman of the Space Telescope Science Institute in Baltimore, Maryland. Its purpose was to do sky surveys in which gravitational lenses are used to seek objects at the furthest distances of the known universe. MACS0647JD was observed by Hubble with 17 filters, spanning near-ultraviolet to near-infrared wavelengths, but the galaxy appeared only in the telescope’s two reddest filters.

“So either MACS0647-JD is a very red object, only shining at red wavelengths, or it is extremely distant and its light has been 'redshifted' to these wavelengths, or some combination of the two," Dan Coe of the Space Telescope Science Institute said. "We considered this full range of possibilities."

The Hubble telescope (Image: NASA)
The Hubble telescope (Image: NASA)

By comparing Hubble’s observations with those from the Spitzer Space Telescope the CLASH team was able to rule out red stars, brown dwarfs, and red galaxies as alternative explanations and concluded that the three images were a match for how the object would appear through the gravitational lens. The final verdict was that MACS0647-JD is an extremely distant galaxy with a huge redshift factor of 11 – the highest observed so far. Since redshift is a measure of how fast an object is speeding away from Earth and hence its distance, that places the galaxy farther away than any other object.

There’s little known about the nature of MACS0647-JD. It’s too far away for spectrography, though further observation by Spitzer and Hubble may uncover new clues as to its composition. However,some things are known. For example, MACS0647-JD is very small – only 600 light years in diameter. Our Milky Way galaxy, by contrast, is 150,000 light years across. This indicates that MACS0647-JD is, or was, a proto galaxy. It may be a small cluster of stars that was typical of the time just after the Big Bang that eventually merged with other clusters to form the familiar galaxies of today.

Compass and scale image of MACS J0647+7015
Compass and scale image of MACS J0647+7015

"This object may be one of many building blocks of a galaxy," said Coe. "Over the next 13 billion years, it may have dozens, hundreds, or even thousands of merging events with other galaxies and galaxy fragments."

The CLASH team will continue to search for more ancient dwarf galaxies because of the insight they provide into the early universe. They believe that if such galaxies were common they could have burned off the hydrogen fog that filled the universe then and made it transparent to light.

Source: NASA

About the Author
David Szondy David Szondy is a freelance writer based in Monroe, Washington. An award-winning playwright, he has contributed to Charged and iQ magazine and is the author of the website Tales of Future Past.   All articles by David Szondy
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5 Comments

How can the light from this object come from so far away? How can we be separated by 13.5B years, almost the entire time the universe has been in existence? If this light started shining towards us 13.5B years ago that means it was that far from us only 420M years after the Big Bang. That doesn't make sense. The numbers don't add up!

JAT
19th November, 2012 @ 09:46 am PST

@JAT

Its 13.3 billion light years, light years is a measure of distance and 420 million years is a measure of time. Your number don't add up because you are using the wrong units of measure.

MarkoPolo
23rd November, 2012 @ 05:20 am PST

JAT. Remember that the universe is expanding and that our galaxy is getting further and further away from that galaxy. This is the reason it appears red, just the same as an ambulance that is moving away from you has a lower sound than one that is sitting still. light gets redder when the source is moving away from you so quickly. What we see now is a glimpse of that galaxy from 13 billion years ago, but the distance wasn't necessarily so great at that time. Then again, our galaxy didn't exist back then either.

Demian Alcazar
24th November, 2012 @ 12:16 pm PST

You guys got it wrong. It took 13.3 billion years for that light to reach us. Light years are not only a measure of distance but of time as well. That light has travelled for 13.3 billion years to get to us. How can it have done so if the universe is itself only 14B years old? It was already 13.3B light years away from us when the universe was only 400+ years old. How can that be??? Somebody is B.Sing somebody here...

JAT
3rd January, 2013 @ 02:54 pm PST

@JAT. I note that no one has left you an explanation and that in itself is clearly your answer.

However the only possible way that light that started travelling 13.3B years ago could only now be reaching us is if:

the speed at which we have been accellerating has been so great that while we may not have been that far appart 13.3 B years ago it took that long to catch up with us. This is of course not the case.

This leads to the obvious conclusion that their calculations are wrong. How could this be??? Again not too hard to work out. It is due to the fact that the Universe has polarity and spin which affects the phisics differently throughout the univers. They are completing their calculations based on a universal constant that light always travels at the same speed. This is not correct.

There is also another reason for the delay of this light from reaching us, in its travels from it's origin it passed near to a black hole and got affected by the Time dilation effects of that object.

Foxy1968
24th March, 2013 @ 09:37 pm PDT
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