| Abstract : | Millisecond pulsars or MSPs (pulsars with a spin period less than 30 ms) act as very precise clocks with accuracies comparable to the best atomic clocks on Earth. Timing studies of MSPs give us key insights into their astrometric, binary properties, and relation to rest of the pulsar population. Precise measurements of these parameters put a newly discovered MSP in its proper place in the pulsar's period versus the period derivative diagram. We will present the timing study of an MSP J1242-4712, discovered by the GMRT High Resolution Southern Sky (GHRSS) survey (Bhattacharyya et al, 2015). This MSP has a periodicity of 5.31 ms and a dispersion measure(DM) of 78.6 pc/cc. Precise localization of this MSP in the image plane with the gated imaging technique, provides additional input for the convergence in the timing fit. We will present the timing study of this pulsar with the upgraded GMRT(uGMRT) band-3 (300-500 MHz) observations spanning from October 2019 to December 2022, i.e, over 3 years of data. This timing study has revealed the compact orbit nature and companion mass of the MSP. This is likely in a special evolutionary phase, a "spider MSP" with a very low mass companion. Frequency-dependent eclipsing is commonly seen for other spider MSPs. We will also present results from investigations of the eclipse properties of MSP J1242-4712.
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