We present the result of astrometric observations of the radio pulsar PSR B0656+14, made using the Very Long Baseline Array. The parallax of the pulsar is π = 3.47 ± 0.36 milliarcsec, yielding a distance 288 -27+33 pc. This independent distance estimate has been used to constrain existing models of thermal X-ray emission from the neutron star's photosphere. Simple blackbody fits to the X-ray data formally yield a neutron star radius R∞∼ 7-8.5 km. With more realistic fits to a magnetized hydrogen atmosphere, any radius between ∼13 and ∼20 km is allowed.
Bibliographical noteFunding Information:
1 National Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801; email@example.com. 2Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064. 3National University of Ireland, Newcastle Road, Galway, Republic of Ireland. 4The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.
- Equation of state
- Stars: neutron