The 12 constellation date table shows that the constellation of May 13 is Taurus.
If you want to find out what constellation the 13th day of the fifth lunar month belongs to, because the constellation is determined by the date of the solar calendar, if you use the date of the lunar calendar to query the constellation, you should provide the corresponding year, so as to convert the date of the lunar calendar into the date of the solar calendar for query. I can't help you until you fill in the year.