VSX Variability Types CTTS Classical T Tauri stars. They have extensive disks that result in strong emission lines (EW(Hα) ≥ 10Å). GCVS types INT and IT. ROT T Tauri stars showing periodic variability due to spots. For those members of this class where special features are well known, the subtype classifications of CTTS/ROT or WTTS/ROT may be applied. Where not precisely known, the subtype of TTS/ROT is used. Close Window