Astronomy Holiday Party

Every year at this time we have a "Holiday Party" for our astronomy club. It is to celebrate all the holidays at this time of year. Everyone brings beverages and snacks and desserts and we have the evening to spend time eating and visiting with each other, which is really nice. When I arrived this evening, one of the members had this mask on! No one has ever worn a mask before, so this was a bit of a surprise. I have no idea which holiday this member was celebrating. He kept the mask on for half an hour, so clearly he was serious about his celebration. I thought it was a very creative mask. The part where the mouth is located lights up, which is pretty cool in a slightly darkened room. It was pretty dramatic, so I asked if I could do his portrait, and here it is. Any ideas which holiday this is?