2024/03/05 by Ankita Ghosh, Bhaswati Bhattacharyya, Ghosh, Ankita +17
Earth and Planetary Sciences · Engineering · Physics and Astronomy · #Astronomical Observations and Instrumentation #FOS: Physical sciences #Geophysics and Gravity Measurements #High Energy Astrophysical Phenomena (astro-ph.HE) #Pulsars and Gravitational Waves Research
paper · pdf · doi:10.48550/arxiv.2403.02646
openalex publication_date 2024/03/05 · openalex created_date 2024/03/07 · openalex updated_date 2026/07/28
We present the timing solution for the 5.31-ms spider millisecond pulsar (MSP) J1242-4712, discovered with the GMRT. PSR J1242-4712 orbits a companion of minimum mass 0.08 M\odot with an orbital period of 7.7 hrs and occupies a relatively unexplored region in the orbital period versus companion mass space. We did not detect gamma-ray pulsations for this MSP, and also could not identify the optical counterpart for PSR J1242-4712 in available optical/near-infrared data. The profile of J1242-4712 evolves with frequency showing a clear single component at lower frequencies and a three-component profile at 650 MHz. PSR J1242-4712 eclipses for a very short duration near superior conjunction (orbital phase ~ 0.23-0.25) below 360 MHz. Moreover, significant DM delays and errors in pulse times of arrivals are observed near inferior conjunction (orbital phase ~ 0.7), along with an observed eclipse in one epoch at 650 MHz. Observed eclipses and significant orbital period variability suggest that PSR J1242-4712 is possibly not a He-WD binary, but has a semi or non-degenerate companion, indicating that this is a ``spider" MSP lying in a region between typical black widows and redbacks. This system may represent a distinct category of spider MSPs, displaying characteristics that bridge the gap between known black widow and redback MSPs.