“The invisible black widow” is changing our view on the structure of ionized matter in our Galaxy

Pulsar radio emission, associated with rapidly spinning neutron stars, enables the estimation of their distances in the Galaxy through dispersion measure (DM). The DM quantifies the dispersive delay experienced by electromagnetic radiation as it traverses ionized matter, such as the interstellar medium (ISM). By measuring this delay across a range of frequencies, astronomers can obtain…

Arachnid astrometry: Charting the distances to celestial spiders with Gaia

Compact binary millisecond pulsars are captivating celestial objects comprised of fast-spinning neutron stars orbiting closely with lighter companion stars. Neutron stars are ultra-dense remnants of massive stars resulting from supernova explosions at the culmination of their lifecycles. These binary pulsars exhibit distinct behaviors due to intense gravitational interactions between the stars. Pulsars emit particle “winds”…


We present the first multi-band optical light curves of PSR J1622-0315, among the most compact known redback binary millisecond pulsars, with an orbital period Porb=3.9 h. We find a flux modulation with two maxima per orbital cycle and a peak-to-peak amplitude of about 0.3 mag, which we attribute to the ellipsoidal shape of the tidally distorted companion star. The optical colours imply a late-F to early-G spectral type companion and do not show any detectable temperature changes along the orbit. This suggests that the irradiation of the star’s inner face by the pulsar wind is unexpectedly missing despite its short orbital period.

binary millisecond pulsar

New source of lithium production found in the Universe

A team of researchers from the Instituto de Astrofísica de Canarias (IAC), the University of Manchester and the Norwegian University of Science and Technology have detected an anomalously high lithium abundance in the atmosphere of the companion star of a binary millisecond pulsar. The lithium abundance is higher compared to stars with the same effective temperature and high-metallicity stars and so the study provides unambiguous evidence for fresh lithium production.

A massive pulsar irradiates a Solar-type star

A massive pulsar irradiates a Solar-type star

Researchers from the UPC and the IAC discover one of the most massive neutron stars. Using a pioneering method, researchers from the Astronomy and Astrophysics Group of the Universitat Politècnica de Catalunya (UPC) and the Canary Islands Institute of Astrophysics (IAC) have found a neutron star of about 2.3 solar masses—one of the most massive…

A 2.3 Solar-mass neutron star in PSR J2215_5135

A 2.3 Solar-mass neutron star in PSR J2215+5135

VIDEO: PSR J2215+5135 Orbital period: 4.14 hours Spin period: 2.61 milliseconds Distance from Earth: about 10.000 light-years The inner face of the companion star, strongly irradiated by the pulsar, is heated up to about 8100 degrees Kelvin. As a consequence, hydrogen absorption lines dominate the visible spectrum of the hot side of the star. The…