To TDE or not to TDE: The luminous transient ASASSN-18jd with TDE-like
  and AGN-like qualities
  We present the discovery of ASASSN-18jd (AT 2018bcb), a luminous
optical/UV/X-ray transient located in the nucleus of the galaxy 2MASX
J22434289--1659083 at $z=0.1192$. Over the year after discovery, Swift UVOT
photometry shows the UV SED of the transient to be well modeled by a slowly
shrinking blackbody with temperature $T \sim 2.5 \times 10^{4} \rm ~K$, a
maximum observed luminosity of $L_\text{max} = 4.5^{+0.6}_{-0.3} \times 10^{44}
\rm ~erg ~s^{-1}$, and a radiated energy of $E = 9.6^{+1.1}_{-0.6} \times
10^{51} \rm ~erg$. X-ray data from Swift XRT and XMM-Newton show a transient,
variable X-ray flux with blackbody and power-law components that fade by nearly
an order of magnitude over the following year. Optical spectra show strong,
roughly constant broad Balmer emission as well as transient features
attributable to He II, N III-V, O III, and coronal Fe. While ASASSN-18jd shares
similarities with Tidal Disruption Events (TDEs), it is also similar to the
newly-discovered nuclear transients seen in quiescent galaxies and faint Active
Galactic Nuclei (AGNs).
