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Strong Balmer absorption lines and the lack of Hα and [O  ii ] emission lines signify that E+A galaxies are post‐starburst systems. Recent studies suggest that E+As may undergo the transition from the ‘blue cloud’ to the ‘red sequence’ and eventually migrate to red‐sequence early‐type galaxies. An observational validation of this scenario is to identify the intervening galaxy population between E+As and the red sequence. Motivated by recent findings with Galaxy Evolution Explorer (GALEX) that an unexpectedly large fraction of early‐type galaxies exhibit ultraviolet (UV) excess (i.e. blue UV – optical colours) as a sign of recent star formation (RSF), we investigate the possible connection of the UV‐excess galaxies to E+As. In particular, we examine the Fundamental Plane (FP) scaling relations of the currently largest sample of ∼1000 E+As selected from the Sloan Digital Sky Survey (SDSS) and ∼20 000 morphologically selected SDSS early‐type galaxies with GALEX UV data. The FP parameters, combined with stellar population indicators, reveal a certain group of UV‐excess early types that bridge between E+As and quiescent red galaxies. The newly identified galaxies are the post‐starburst systems characterized by UV‐excess but no Hα emission. This is essentially a conceptual generalization of ‘E+A’, in that the Balmer absorption line in the ‘E+A’ definition is replaced with UV – optical colours that are far more sensitive to RSF than the Balmer lines. We refer to these UV‐excess galaxies as ‘E+a’ galaxies (named after ‘E+A’), which stand for elliptical (‘E’) galaxies with a minority of A‐type (‘a’) young stars. The species are either (1) galaxies that experienced starbursts weaker than those observed in E+As (1 ∼ 10 per cent of E+As, ‘mild E+As’) or (2) the products of passively evolved E+As after quenching star formation quite a while ago (∼1 Gyr, ‘old E+As’). We suggest that the latter type of E+a galaxies (i.e. old ‘E+As’) represents the most recent arrival to the red sequence in the final phase of the E+A to red early‐type transition.

The Fundamental Planes of E+A galaxies and GALEX UV‐excess early‐type galaxies: revealing their intimate connection