Zeta Ophiuchi was once in close orbit with another star, before being ejected when that companion was destroyed in a supernova explosion. Spitzer’s infrared data reveal a dramatic shock wave that was formed by matter breaking away from the star’s surface and hitting the gas in its wake. The Chandra data show a bubble of X-ray emission around the star, produced by gas that has been heated by the shock wave to tens of millions of degrees. Chandra data help explain more about the history of this runaway star. Credit: X-ray: NASA/CXC/Univ. of Cambridge/J. Sisk-Reynés et al.; Radio: NSF/NRAO/VLA; Optical: PanSTARRS
- Zeta Ophiuchi is a single star that probably once had a companion that was destroyed when it went supernova.
- The supernova explosion sent Zeta Ophiuchi, seen in Spitzer (green and red) and Chandra data (blue), into space.
- The X-rays detected by Chandra originate from gas that has been heated to millions of degrees by the effects of a shock wave.
- Scientists are working to match computational models of this object to explain the data obtained at different wavelengths.
Zeta Ophiuchi is a star with a complicated past, as it was probably ejected from its birthplace by a powerful stellar explosion. A new detailed look from NASA’s Chandra X-ray Observatory helps explain more about the history of this runaway star.
Located about 440 light-years from Earth, Zeta Ophiuchi is a hot star that is about 20 times more massive than the Sun. Previous observations have provided evidence that Zeta Ophiuchi was once in close orbit with another star, before being ejected at about 100,000 miles per hour when that companion was destroyed in a supernova explosion more than a million years ago .
In fact, previously released infrared data from NASA’s now-retired Spitzer Space Telescope, seen in this new composite image, reveal a dramatic shock wave (red and green) that was formed by the matter collapsing it drifted away from the star’s surface and crashed into the gas inside it. road The Chandra data reveal a bubble of X-ray emission (blue) located around the star, produced by gas that has been heated by the effects of the shock wave to tens of millions of degrees.
A team of astronomers has built the first detailed computer models of the shock wave. They have begun testing whether the models can explain data obtained at different wavelengths, including X-ray, infrared, optical and radio observations. The three different computer models predict fainter X-ray emissions than observed. Also, the bubble of X-ray emission is brighter near the star, while two of the three computer models predict that the X-ray emission should be brighter near the shock wave. The team of astronomers was led by Samuel Green of the Institute for Advanced Study in Dublin, Ireland.
In the future, these scientists plan to test more complicated models with additional physics, including the effects of turbulence and particle acceleration, to see if the agreement with the X-ray data will improve.
A paper describing these results has been accepted into the journal Astronomy and Astrophysics. The Chandra data used here were originally analyzed by Jesús Toala of the Instituto de Astrofísica de Andalucía in Spain, who also wrote the proposal that led to the observations.
Reference: “Thermal emission of bow shocks. II. 3D magnetohydrodynamic models of Zeta Ophiuchi” by S. Green, J. Mackey, P. Kavanagh, TJ Haworth, M. Moutzouri and VV Gvaramadze, Accepted, Astronomy and Astrophysics.DOI: 10.1051/0004-6361/20224353
NASA’s Marshall Space Flight Center manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.