Universe ID: 12806

'Winking' Star May Be Devouring Wrecked Planets

Released on December 21, 2017

Zoom into RZ Piscium, a star about 550 light-years away that undergoes erratic dips in brightness. This animation illustrates one possible interpretation of the system, with a giant planet near the star slowly dissolving. Gas and dust stream away from the planet, and these clouds occasionally eclipse the star as we view it from Earth.

Music: "Frozen Wonder" from Killer Tracks

Watch this video on the NASA Goddard YouTube channel.

Credit NASA's Goddard Space Flight Center/CI Lab

Complete transcript available.

Astronomers studying the star RZ Piscium have found evidence suggesting its strange, unpredictable dimming episodes may be caused by vast orbiting clouds of gas and dust, the remains of one or more destroyed planets.

Young stars are often prodigious X-ray sources. Observations using the European Space Agency's XMM-Newton satellite, show that RZ Piscium is, too. Its total X-ray output is roughly 1,000 times greater than our Sun's. Ground-based observations show the star's surface temperature to be about 9,600 degrees Fahrenheit (5,330 degrees Celsius), only slightly cooler than the Sun's. They also show RZ Piscium is enriched in the tell-tale element lithium, which is slowly destroyed by nuclear reactions inside stars and serves as a clock indicating the elapsed time since a star's birth.

Ground-based telescopes also reveal large amounts of dust and hydrogen-rich gas in the system, suggesting that large blobs of this material are orbiting the star and causing the brightness dips.

The best explanation that accounts for all of the available data, say the researchers, is that the star is encircled by debris representing the aftermath of a disaster of planetary proportions. It's possible the star's tides may be stripping material from a close substellar companion or giant planet, producing intermittent streams of gas and dust, or that the companion is already completely dissolved. Another possibility is that one or more massive gas-rich planets in the system underwent a catastrophic collision in the astronomically recent past.

This animation sequence shows a wide view of one possible interpretation of the RZ Piscium system. Blobs of gas and dust orbit the star, producing its puzzling irregular brightness drops. This material may have been released by the tidal disruptions or collisions of gas-rich planets or, as shown here, an orbiting gas giant planet that is currently dissolving.

Credit NASA's Goddard Space Flight Center/CI Lab