Multiband optical variability of a newly discovered 12 blazars sample from 2013-2019

Here we present the first optical photometric monitoring results of a sample of 12 newly discovered blazars from the ICRF - Gaia CRF astrometric link. The observations were performed from April 2013 to August 2019 using eight telescopes located in Europe. For a robust test for the brightness and colour variability, we use Abbe criterion and F-test. Moreover, linear fittings are performed to investigate the relation in the colour-magnitude variations of the blazars. Variability was confirmed in the case of 10 sources; two sources, 1429+249 and 1556+335 seem to be possibly variable. Three sources (1034+574, 1722+119, and 1741+597) have displayed large amplitude brightness change of more than one magnitude. We found that the seven sources displayed bluer-when-brighter variations, and one source showed redder-when-brighter variations. We briefly explain the various AGN emission models which can explain our results.

Automated summary

We present the first optical photometric monitoring of 12 newly discovered blazars from the ICRF - Gaia CRF astrometric link. Variability was confirmed in 10 sources, with two sources possibly being variable. Additionally, three sources displayed large amplitude brightness change of more than one magnitude. Our results suggest that bluer-when-brighter variations are more common among the studied sources. We also discuss various AGN emission models that can explain our findings.