The Quasar CTD 135 Is Not a Compact Symmetric Object

The radio-loud quasar CTD 135 (2234+282, J2236+2828) has been proposed as a candidate compact symmetric object (CSO), based on its radio structure revealed by multi-frequency very long baseline interferometry (VLBI) imaging observations milliarcsec angular scales. CSOs are known young jetted active galactic nuclei (AGN) whose relativistic plasma jets misaligned with respect to the line of sight. peculiarity CSO was detection in ?-rays, while vast majority ?-ray emitting AGN blazars pointing close our viewing direction. Since only handful sources, unambiguous identification single is important for studying this rare class objects. By collecting and interpreting observational data from recent literature, we revisit classification 135. We present evidence that object, flat-spectrum core high brightness temperature, variability at multiple wavebands, infrared colours should be classified blazar rather than CSO.