MACS0647-JD is a galaxy with a redshift of about z = 10.7, equivalent to a light travel distance of 13.26 billion light-years (4 billion parsecs). If the distance estimate is correct, it formed about 427 million years after the Big Bang.[2][3][4][5]
Details
JD refers to J-band Dropout – the galaxy was not detected in the so-called J-band (F125W), nor in 14 bluer Hubble filters. It only appeared in the two reddest filters (F140W and F160W).
It is less than 600 light-years wide, and contains roughly a billion stars.
The location of the galaxy is in the constellation Camelopardalis, which is also the location of the gravitational lensing cluster that helped discover this galaxy: MACSJ0647+7015 at z = 0.591.[7]
MACS0647-JD was announced in November 2012, but by the next month UDFj-39546284, which was previously thought to be z = 10.3, was said to be at z = 11.9,[8] although more recent analyses have suggested the latter is likely to be at a lower redshift.[9]
Infrared NIRCam imaging of MACS0647-JD by the James Webb Space Telescope (JWST) in September 2022 determined a photometric redshift of 10.6±0.3, in agreement with the previous Hubble estimate. Additional spectroscopic observations by JWST will be needed to accurately confirm the redshift of MACS0647-JD.[1]