Nine potential candidates for the state Senate seat in the 4th Middlesex district submitted their nomination papers for certification by Tuesday's deadline.

The local town clerks and Woburn's City Clerk must now certify the signatures and the candidates must file them with the Secretary of State's office by 5 p.m. on Tuesday, Oct. 9.

Three hundred certified signatures are required for a candidate to be placed on the ballot.

There are potentially six Democratic candidates, two Republicans and one unenrolled entrant.

The primary election for the Democrats and Republicans will be held on Tuesday, Nov. 13. The winners from each party will join unenrolled candidate Thomas Fallon of Burlington (if his signatures are certified and submitted) on the ballot in the final election on Tuesday, Dec. 11.

The special election is being held to replace state Sen. Robert Havern, who resigned on Aug. 27. The 4th Middlesex district includes Arlington, Billerica, Burlington, precincts 1-2 and 4-7 in Lexington, and wards 1 and 3-7 in Woburn.

The Democratic field includes three sitting state representatives - James Marzilli of Arlington, Charles Murphy of Burlington and Patrick Natale of Woburn, along with Kenneth Donnelly of Arlington, former Burlington selectman Virginia Mooney and Lexington Town Meeting member and former Burlington resident Robert Peters.

The Republicans are Linda Fosburg of Lexington and Brion Cangiamila of Billerica.

The last day for voters to register for the primary election is Wednesday, Oct. 24. Town clerk's offices in the he district and Woburn's City Clerk's office will be open until 8 p.m. that evening for election registration business only.

(Burlington editor John White and Burlington news reporter Steve DeMarco contributed to this report.)

Democrats

Kenneth Donnelly

James Marzilli

Virginia Mooney

Charles Murphy

Patrick Natale

Robert Peters

Republicans

Brion Cangiamila

Linda Fosburg

Unaffiliated

Thomas Fallon