Zeta Ophiuchi was once in close orbit with another star before it was ejected when that satellite was destroyed in a supernova explosion. The infrared data from Spitzer revealed a spectacular shock wave formed by matter blown off the star’s surface and slamming into gas on its way. The Chandra data show a bubble of X-ray emission surrounding the star produced by gas that has been heated by the shock wave to tens of millions of degrees. The Chandra data are helping to tell more about the story 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 one 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), hurtling into space.
- The X-rays detected by Chandra originate from gas that has been heated to millions of degrees by the impact 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 detailed new look from NASA’s Chandra X-ray Observatory helps tell more about the story of this runaway star.
Located approximately 440 light-years from Earth, Zeta Ophiuchi is a hot star that is about 20 times more massive than the Sun. Evidence that Zeta Ophiuchi was once in close orbit with another star before being ejected at about 100,000 miles per hour when that satellite was destroyed in a supernova explosion more than a million years ago has been provided by previous observations.
Indeed, previously released infrared data from NASA’s now-retired Spitzer Space Telescope, seen in this new composite image, reveal a spectacular shock wave (red and green) formed by matter blown off the star’s surface and slamming into gas in its path . A bubble of X-ray emission (blue) located around the star, produced by gas that has been heated by the impact of the shock wave to tens of millions of degrees, is revealed by Chandra data.
A team of astronomers has constructed 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. All three different computer models predict weaker X-ray emission than observed. In addition, the bubble of X-rays is brightest near the star, while two of the three computer models predict that the X-rays should be brighter near the shock wave. The team of astronomers was led by Samuel Green of the Dublin Institute for Advanced Study in Ireland.
In the future, these scientists plan to test more complex models with additional physics—including the effects of turbulence and particle acceleration—to see if the agreement with the X-ray data improves.
A paper describing these results has been accepted into the journal Astronomy and Astrophysics. The Chandra data used here were originally analyzed by Jesus Toala of the Institute of Astrophysics of Andalusia in Spain, who also wrote the proposal that led to the observations.
Reference: “Heat emission from nose impacts. II. 3D magnetohydrodynamic models of Zeta Ophiuchus” by S. Green, J. Mackey, P. Kavanagh, TJ Haworth, M. Moutzouri and VV Gvaramadze, Accepted, Astronomy and Astrophysics.DOI: 10.1051/0004-6361/202243531
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 flights from Burlington, Massachusetts.
Add Comment