The residency status of former selectman John Mariano will be the focus of a public hearing before the Norwell Board of Registrars Tuesday. In the days before town election, two Norwell residents filed a challenge that questioned Mariano’s right to take part in town politics. The Board of Registrars met in emergency session, voting 3-1 to address the issue on May 29 at 7 p.m. in the Osborne Room at Town Hall. Mariano lost his seat on May 19 to challenger David DeCoste by a vote of 2,308-1,683. Mariano called the residency issue a political attack and said he will attend the hearing, though it comes too late to clear his name before voters. Mariano also said he is proud of what he accomplished for Norwell during his 18 years of service, a dozen as a selectman.