Improving NASA/IPAC Extragalactic Database Redshift Calculations

The NASA/IPAC Extragalactic Database (NED) is an impressive tool for finding near-exhaustive information on millions of astrophysical objects. Here, we outline a small systematic error that occurs in NED because low-redshift approximation used when making the correction from redshifts heliocentric frame to cosmic microwave background (CMB) rest frame. It means historically systematically misreported values CMB-frame by up ?10?3z (about 0.001 at redshift 1). This error, and therefore impact applications requiring precise has potential be significant—for example, ?10?4 low could resolve Hubble tension. We have consulted with team they are updating software remove this so these corrections accurate all redshifts. explain changes how currently reports.