Dunlop Institute for Astronomy & Astrophysics | University of Toronto | 2016 Dec 08
[img3="Artist’s rendition of a typical millisecond pulsar binary system in which the shape of the companion star (l.) is deformed by the gravitational pull of the pulsar (r.) seen emitting beams of radiation. Credit: NASA"]http://www.dunlap.utoronto.ca/wp-conten ... 1200px.jpg[/img3][hr][/hr]A professional astrophysicist and an amateur astronomer have teamed up to reveal surprising details about an unusual millisecond pulsar (MSP) binary system comprising one of the fastest-spinning pulsars in our galaxy and its unique companion star.
Their observations ... are the first to identify “star spots” on an MSP’s companion star. Plus, the observations show that the companion has a strong magnetic field, and provide clues into why pulsars in some MSP binaries switch on and off. ...
In a typical MSP binary, the gravity of the pulsar distorts the shape of the companion star, pulling it into a teardrop-shape. As it circles the pulsar, we see a cyclical rise and fall in the companion’s brightness. The companion is brightest at two points in its orbit, when we see its broad, tear-shaped profile; it is dimmest midway between those two points, when we see its smallest, circular profile. Naturally, the light curve measuring the brightness rises and falls in step with the companion’s orbital period.
But Antoniadis and van Staden’s observations revealed that the brightness of the companion wasn’t in sync with its 15-hour orbital period; instead the star’s peaks in brightness occur progressively later relative to the companion’s orbital position. ...
An Active, Asynchronous Companion to a Redback Millisecond Pulsar - André van Staden, John Antoniadis
- Astrophysical Journal Letters 833(1):L12 (2016 Dec 10) DOI: 10.3847/2041-8213/833/1/L12
arXiv.org > astro-ph > arXiv:1609.08024 > 26 Sep 2016 (v1), 07 Dec 2016 (v2)