When a pulsar, a rapidly-rotating neutron star, finds itself in a tight orbit with another star, it will siphon mass from it, leading to electromagnetic emissions from the pulsar-star system. When the star is low in mass, forming an X-ray binary, the pulsar will heat and slowly evaporate the companion star, leading to the creation of “black widow” systems when the companion star loses enough mass. (Credit: ESA)
Nearly half of all stars are born in binary systems, with the most massive ones dying the fastest. It’s not pretty for the “second” star.
An illustrated view of a black widow pulsar and its stellar companion. The pulsar’s gamma-ray emissions (magenta) strongly heat the facing side of the star (orange). The pulsar is gradually evaporating its partner. (Credit: NASA’s Goddard Space Flight Center/Cruz deWilde)
Formed when massive stars die in a core-collapse supernova, pulsars are rapidly spinning neutron stars.
This side-by-side set of images shows a series of views of the Crab Pulsar and its surrounding environment taken by NASA’s Chandra X-ray telescope (left) and NASA’s Hubble space telescope (right) over the 6-month period from November 2000 to April 2001. Formed from a star that went supernova in 1054, the Crab pulsar is one of the youngest known neutron stars. (Credits: NASA/CXC/ASU/J.Hester et al.; NASA/HST/ASU/J.Hester et al.; stevebd1/YouTube)
The fastest rotators — millisecond pulsars — “spin up” from siphoning matter off of nearby stars.
This image shows the illustration of a massive neutron star, along with the distorted gravitational effects an observer might see if they had the capability of viewing this neutron star at such a close distance. While neutron stars are famous for pulsing, not every neutron star is a pulsar. The fastest pulsars, known as millisecond pulsars, rotate at more than 100 times per second, with the current record holder completing a whopping 766 rotations each second. (Credit: Daniel Molybdenum/flickr and raphael.concorde/Wikimedia Commons)
Whenever stars form, they aren’t always singlets, but often possess a companion.
An X-ray binary is formed when a neutron star or black hole is orbited by a much larger, less dense, massive star. The material accretes onto the dense stellar remnant, heats up and ionizes, and emits X-rays. Many pulsing neutron stars are known to have binary companions, with a wide variety of distances and masses possible for the companion star. Farther out, additional planetary or stellar companions are possible. (Credit: NASA/CXC/M. Weiss)
Furthermore, in dense stellar environments — like globular clusters — gravitational ejection and capture are common.
Here in the heart of Omega Centauri, one of the largest, richest globular clusters visible from Earth’s location within the Milky Way, lots of stars of various colors have been imaged. Owing to the dense nature of this environment, gravitational interactions between stars and stellar systems are common, often resulting in ejections, gravitational captures, and sometimes, low-mass stars (or even failed stars) winding up in tight orbits with millisecond pulsars. (Credit: NASA, ESA, and the Hubble SM4 ERO Team)
This illustration shows a neutron star with an accretion disk, siphoning mass off of a low-mass companion star. Many of these systems with neutron stars will have millisecond pulsars for their neutron stars, and the neutron star’s pulsing “jets” will strike, and slowly destroy, the companion star. (Credit: Vdsluys/Wikimedia Commons)
In close-in LMXB systems, these pulsars strip their companion stars of atmospheres through energetic winds.
Using the combined data from NASA’s Chandra (X-ray), Hubble (visible light), and IXPE (X-ray polarization, in light blue), pulsar winds coming off of the Vela pulsar, a neutron star just ~10,000 years old, can easily be seen. These jets, if the pulsar has a binary companion (Vela has a high-mass one), can damage or even potentially destroy the companion star. (Credits: X-ray: (IXPE) NASA/MSFC/Fei Xie & (Chandra) NASA/CXC/SAO; Optical: NASA/STScI Hubble/Chandra processing by Judy Schmidt; Hubble/Chandra/IXPE processing & compositing by NASA/CXC/SAO/Kimberly Arcand & Nancy Wolk)
