Hubble finds most distant known galaxy
Two NASA telescopes working together have discovered the most distant galaxy ever seen in the Universe. It is so far away that its light has taken an incredible 13.3 billion years to reach us.
It started its journey only 420 million years after the Big Bang. The Universe was then only three per cent of its present age of 13.7 billion years.
The tiny smudge was detected by the Hubble space telescope and confirmed by its space cousin called Spitzer. But they were aided by a natural pheneomenon in space called gravitational lensing.
In this case, a remote cluster of galaxies lying about five billion light-years away, between it and the Earth, acted like a telescope to bend and magnify its light. That produced three separate images of the record-breaking galaxy which appeared about eight, seven and two times brighter than it would otherwise have done.
The brightness boost, a phenomenon predicted by legendary physicist Albert Einstein, made it much easier for astronomers to detect the galaxy, labelled MACS0647-JD, and identify it.
The galaxy is so small – less than 600 light-years wide – that scientists believe they are seeing it in the first stages of forming a larger galaxy. Astronomers believe that a typical galaxy of similar age should be around 2,000 light-years across. Our own Milky Way galaxy is 150,000 light-years wide.
The discovery was made by an international team of astronomers carrying out the Cluster Lensing And Supernova Survey with Hubble (CLASH), and led by Marc Postman of the Space Telescope Science Institute in Baltimore.
They are using the magnifying qualities of massive clusters of galaxies to help them find remote galaxies that lie behind them.
Dr Postman said of the new discovery: “This cluster does what no man-made telescope can do. Without the magnification, it would require a Herculean effort to observe this galaxy.”