Optical Observations of PSR J0205+6449

PSR J0205+6449 is a X-ray and radio pulsar in supernova remnant 3C 58. We report on observations of the central region of 3C 58 using the 4.2-m William Herschel Telescope with the intention of identifying the optical counterpart of PSR J0205+6449 and characterising its pulsar wind nebula. Around the pulsar position we identified extended emission with a magnitude of B = 23.m97 ± 0.10, V = 22.m95 ± 0.05 and R = 22.m15 ± 0.03 consistent with a pulsar wind nebula. From the R-band image we identified three knots with mR = 24.m08±0.07 (o1), 24.m15 ± 0.07 (o2) and 24.m24 ± 0.08 (o3). We confirm the presence of an optical pulsar wind nebula around PSR J0205+6449 and give an upper limit of mR ≈ 24 for the optical magnitude of the pulsar. Furthermore we make the tentative suggestion that our object o1, with an mR ≈ 24.08 is the optical counterpart. If confirmed the pulsar would have an LR/Lx ≈ 0.004 and an optical efficiency of about 5 % of the Crab pulsar. Such a low efficiency is more consistent with the characteristic age of the pulsar rather than that of SN 1181