DuckCorp Dico

Found one definition

1.                 From English - German Ding/FreeDict dictionary ver. 1.9-fd1:
                   
   
   
                   
                     
   soft X-ray transient /sˈɒft ˈɛks ɹˈeɪ tɹˈansiənt/ (SXT /ˌɛsˌɛkstˈiː/)
   Röntgennova <fem>, Röntgen-Nova <fem> [astron.]