We present the colour and flux variability analysis at 3.4{mu}m (W1 band) and 4.6{mu}m (W2 band) of 492 narrow-line Seyfert 1 (NLSy1) galaxies using archival data from the Wide-field Infrared Survey Explorer (WISE). In the WISE colour-colour, (W1-W2) versus (W2-W3) diagram, ~58 per cent of the NLSy1 galaxies of our sample lie in the region occupied by the blazar category of active galactic nuclei (AGNs). The mean W1-W2 colour of candidate variable NLSy1 galaxies is 0.99+/-0.18mag. The average amplitude of variability is 0.11+/-0.07mag in long term (multiyear) with no difference in variability between W1 and W2 bands. The W1-W2 colour of NLSy1 galaxies is anticorrelated with the relative strength of [OIII] to H{beta}, strongly correlated with continuum luminosity, black hole mass, and Eddington ratio. The long-term amplitude of variability shows weak anticorrelation with the FeII strength, continuum luminosity and Eddington ratio. A positive correlation between colour as well as the amplitude of variability with the radio power at 1.4GHz was found for the radio-detected NLSy1 galaxies. This suggests non-thermal synchrotron contribution to the mid-infrared colour and flux variability in radio-detected NLSy1 galaxies.

Cone search capability for table J/MNRAS/483/2362/table1 (Variability information)