SIMBAD references

NGC 5905 was observed with ROSAT five times, three times during the ROSAT all-sky survey (RASS) and twice in the pointed observing mode. The soft X-ray properties of the nucleus of NGC 5905 derived from the RASS observations, namely high-amplitude flux variability on timescales of days, the extremely soft spectrum (photon index {GAMMA}=4), and high peak luminosity of L_X=7x10⁴²ergs/s, are all inconsistent with its optical classification as HII-type, i.e. starburst galaxy. During the pointed observations taken two years later, the X-ray luminosity was down by a factor of >80. Possible mechanisms, which can produce the high state, are discussed. Tidal disruption of a star near a central black hole is in good agreement with the observations.