Units of relativistic time scales and associated quantities

TL;DR

This paper proposes standardized nomenclature for units of astronomical quantities associated with relativistic time scales, promoting clarity and consistency in scientific communication.

Contribution

It introduces a clear terminology for units related to TCG, TCB, TT, and TDB, avoiding ambiguous expressions like 'TDB units' and aligning with IAU recommendations.

Findings

Recommends using 'TCG-compatible', 'TCB-compatible', 'TT-compatible', 'TDB-compatible'

Advises using 'second' and 'meter' without adjectives for all quantities

Enhances clarity in scientific descriptions of relativistic time scale units

Abstract

This note suggests nomenclature for dealing with the units of various astronomical quantities that are used with the relativistic time scales TT, TDB, TCB and TCG. It is suggested to avoid wordings like "TDB units" and "TT units" and avoid contrasting them to "SI units". The quantities intended for use with TCG, TCB, TT or TDB should be called "TCG-compatible", "TCB-compatible", "TT-compatible" or "TDB-compatible", respectively. The names of the units second and meter for numerical values of all these quantities should be used with out any adjectives. This suggestion comes from a special discussion forum created within IAU Commission 52 "Relativity in Fundamental Astronomy".