day of the ghost
Refers to 鬼宿日, a day associated with the ghost constellation in traditional almanacs.
See also: 鬼宿日
In the calendar, the day of Tamoo no Hoshi is considered Kishukubi.
Full name of the constellation; 魂緒の星 is an abbreviation.
The name derives from Chinese astronomy, where the constellation is associated with a ghost or spirit. The exact derivation of the Japanese reading is uncertain.