Star Furniture continues its support of Big Brothers Big Sisters of Greater Lafayette with the opening of Big Brothers Big Sisters Auction House, now located next to Big Brothers Big Sisters on the corner of Fortune Drive and Creasy Lane.   All profits from the auctions will benefit Big Brothers Big Sisters and be used to provide caring mentors for at-risk youth in Tippecanoe County.   Weekly auctions will be open to the public and held on Saturday evenings from 6:00 p.m. to 9:00 p.m.   Those interested in consigning or donating items are encouraged to call 317-509-2138.