«Hung by the Fire» by Viola Grace

Teaching the visitors about the holiday stars is fun until a man who burns brighter than the sun enters Vixen’s orbit.
 
 
Vixen chooses life with astronomy, and she ends up as an educator and a researcher for a tiny observatory struggling to make ends meet.
When Vi arrives, she makes an impression and takes over most of the day-to-day operations, which is fine until an elf comes calling.
Xander has been sent to bring Vixen home, but he doesn’t know how he will go about convincing her that it is a good idea, until he asks her out and she tells him what she wants.
Magic and wonder are the hallmarks of Christmas, and these two have it in spades.