Astronomers have identified the millisecond pulsar PSR J0435+3233 as part of a rare triple star system. The pulsar rotates with a period of 3.2 milliseconds, yet its rotation slows down approximately 100 times faster than that of other millisecond pulsars within the Milky Way.
The object was initially detected using the Chinese FAST radio telescope. Subsequent observations conducted with optical and infrared observatories, as well as the Fermi gamma-ray space telescope, confirmed the existence of two stellar companions.
The first companion is a white dwarf, around which the pulsar orbits with a period of about 8 days. The second companion is a subgiant star, which has evolved past the main sequence but has not yet become a red giant.
A research team led by Zonglin Yang from the National Astronomical Observatories of the Chinese Academy of Sciences suggests that all three stars likely formed together. This hypothesis is supported by the pulsar's location in a relatively isolated region of the galaxy.
The rapid deceleration of the pulsar may indicate a strong magnetic field and an unusual formation path. This system provides researchers with a unique opportunity to study how gravitational interactions between three stars influence their long-term evolution.
