Last week we brought you news of Earendel, the newest farthest star. Its light traveled 12.9 billion years to reach us, and that is overwhelmingly far for a universe that is only 13.8 billion years old. But Earendel is just one star, and galaxies, with their diversity of stars and bright gas, can be seen to even greater distances, and today we have a new farthest galaxy to present. Like Earendel, this object’s light was enhanced by a galaxy cluster acting as a gravitational lens.

Cataloged as HD1, this smudge of light was discovered in 1,200 hours of data taken by the combo of the Subaru Telescope, VISTA telescope, UK Infrared Telescope, and Spitzer Space Telescope. It was then confirmed with Atacama Large Millimeter/submillimeter Array (ALMA).

Or at least confirmed as well as anything this faint and far can be confirmed. According to ALMA observer Akio Inoue: We found a weak signal at the frequency where an oxygen emission line was expected. The significance of the signal is 99.99%. If this signal is real, this is evidence that HD1 exists 13.5 billion light-years away, but we cannot be sure without a significance of 99.999% or more.

This work is published in The Astrophysical Journal with lead author Yuichi Harikane.

This galaxy formed when the universe was just 300 million years old and is remarkably bright. It is either undergoing massive star formation or has an active black hole or both.

When… is it too soon to say when? When JWST starts doing science, HD1 is selected to be studied during JWST’s cycle 1 observations.

More Information

NAOJ press release

RAS press release

“A Search for H-Dropout Lyman Break Galaxies at z~12-16,” Yuichi Harikane et al., 2022 April 8, The Astrophysical Journal

“Are the newly-discovered z ∼ 13 drop-out sources starburst galaxies or quasars?“, Fabio Pacucci et al., 2022 April 7, Monthly Notices of the Royal Astronomical Society