Astronomers, using the Hubble Space Telescope and a natural consequence of large scale gravity, have imaged the most distant galaxy identified so far.
Measured at just 600 light years across, quite small in cosmic terms, MACS0647-JD was imaged as it was just 420 million years after the theorized big bang, or at 3 percent of the current age of the universe — $13.7 billion years.
“This object may be one of many building blocks of a galaxy,” said the study’s lead author, Dan Coe of the Space Telescope Science Institute, of Baltimore,Md. “Over the next 13 billion years, it may have dozens, hundreds, or even thousands of merging events with other galaxies and galaxy fragments.”
For comparison our Milky Way galaxy is 150,000 light years across. If Coe is correct about MACSO647-JD’s evolution, it will be billions of years before the light evidence from those major changes reach Earth-bound scientists.
The discovery was made with the 22-year-old Hubble; a second NASA great observatory, the 9-year-old Spitzer Space Telescope; and MACS J0647+7015, a closer massive cluster of galaxies. The cluster magnified the faint light coming from MACS0647-JD with its intense gravity to make it bright enough for the discovery.
The new distance champion is the second remote galaxy uncovered in the CLASH survey. Cluster Lensing and Supernova Survey with Hubble, is a multi-wavelength census of 25 hefty galaxy clusters with two Hubble instruments, the Advanced Camera for Surveys and Wide Field Camera-3. Earlier this year, the CLASH team announced the discovery of a galaxy that existed when the universe was 490 million years old, 70 million years later than the new record-breaking galaxy.
Hubble has been upgraded over its life time by NASA space shuttle crews. The most recent shuttle mission, the fifth, unfolded in May 2009. Hubble’s successor, the James Webb Space Telescope, is under development and heading toward a launch in late 2018. One of the JWST’s missions is to search for even more distant star systems, or galactic fragments.