On February 9 in Gasson 100, Newton resident David Iwatsuki and his son Zack, 3, at the Tet Festival, a Lunar New Year celebration sponsored by the Vietnamese Students’ Association at Boston College. The event featured a lion dance performed by the Chinese Students’ Association, a dance choreographed to “Hoa Mi Toc Nau” (“Brown-Haired Nightingale”), a traditional Vietnamese song, and games, food, and arts and crafts tables. Tet (short for Tet Nguyen Dan, which means “the first day”) is a Vietnamese national holiday that lasts for three days and marks the beginning of spring in Vietnam.