What is the Russian tradition to do on Christmas Eve when first star appears?

On Christmas Eve, Russians traditionally gather around the table for a meal called Svyatoi Vecher (Holy Evening ) which is usually meatless as Christmas Eve marks the end of 40 days of Advent fast.

When the firt stars appears in the sky (a reference to the Star of Bethlehem) children go caroling in their neighborhood collecting sweets and fruits.