PSR J0210+5845: Ultra-wide binary pulsar with a B6 V main sequence star companion
Abstract
We report on radio timing observations of PSR J0210+5845 that reveal large deviations from typical pulsar spin-down behaviour. We interpret these deviations as being due to the binary motion around the V = 13.5 star 2MASS J02105640+5845176, which is coincident in terms of its celestial position and distance with the pulsar. Archival observations and new optical spectroscopy have identified this object as a B6 V star, with a temperature of Teff ≈ 14 000 K and a mass of Mc = 3.5 to 3.8 M⊙, making it the lowest mass for a main sequence star known to be orbiting a non-recycled pulsar. We find that the timing observations constrain the binary orbit to be wide and moderately eccentric, with an orbital period of Pb = 47−14+40 yr and eccentricity of e = 0.46−0.07+0.10. We predict that the next periastron passage will occur between 2030 and 2034. Due to the low companion mass, we find that the probability for a system with the properties of PSR J0210+5845 and its binary companion to survive the supernova is low. We show that a low velocity and fortuitously directed natal kick is required for the binary to remain bound during the supernova explosion and we argue that an electron-capture supernova is a plausible formation scenario for the pulsar.
- Publication:
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Astronomy and Astrophysics
- Pub Date:
- February 2024
- DOI:
- 10.1051/0004-6361/202348578
- arXiv:
- arXiv:2312.01892
- Bibcode:
- 2024A&A...682A.178V
- Keywords:
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- binaries: general;
- stars: evolution;
- stars: neutron;
- pulsars: individual: PSR J0210+5845;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- Accepted to A&