HD1 is the earliest and most distant known galaxy yet identified in the observable universe, having a spectroscopic redshift of z = 13.27, meaning that the light from the galaxy travelled for 13.5 billion years on its way to Earth, which due to the expansion of the universe, corresponds to a proper distance of approximately 33.4 billion light-years (10.2 billion parsecs).[1][2][4][5][6][7] The observed position of HD1 was determined to be about 330 million years after the Big Bang.[8] Another similar high-redshift galaxy, HD2, was determined to be nearly as far away as HD1.[9]