SIMBAD references

We report the results of our search for pulsed radio emission from Geminga carried out in 1992, 1993 and 1996-1997 at 102.5 MHz using the BSA radiotelescope of the Pushchino Radioastronomy Observatory. The Geminga radio pulsar (PSR J0633+1746) was detected in all three observation periods. With the best signal to noise ratio Geminga was detected in records taken in 1993, when the maximum passband of the radiotelescope was used for the searches. The main criterion for radio pulsar detection was the presence of records containing the dominant spectral line at the rotation frequency of the pulsar Omega=4.22 Hz in the amplitude spectra. The method of averaging the amplitude spectra, obtained for many days in February-June 1993, was used for the determination of the mean flux density of the Geminga radio emission at 102.5 MHz.We report the main parameters of the pulsar PSR J0633+1746, obtained from our observations. The mean flux S₁₀₂₌₈₍+3_-2) mJy. The average pulse profile is very wide and has a shape like in X-rays (Halpern & Holt, 1992). The profile width on the 0.5 level W_0.5 ~= 120 ms, i.e. about 180°. The dispersion measure DM=3.2 ± 0.3 pc x cm^-3. A timing analysis, which was performed for the best profiles, obtained from 1992 to 1997, yields values for the period P and derivative {dot}P, which are, within error limits, in agreement with the data published by Mayer-Hasselwander et al. (1994). We discuss possible reasons for the extremely low radio luminosity of the Geminga pulsar.