Scientists have studied two dead stars, which they say are giving us a glimpse as to how our Solar System might look like a few billion years from now.
The burnt-out stars are located in the Hyades cluster, in the Constellation Taurus, about 150 light-years from Earth. They are so-called white dwarfs - the exhausted cores of average-size stars not unlike our Sun.
In just a few billion years from now, the Sun will use up all of its hydrogen fuel and will swell to turn into a red giant, the BBC reported.
Then it will dump a large proportion of its gaseous mass to leave a hot, compact and faintly glowing ember.
The Sun should also be pulling in rocks that get too close, gravitationally crushing them into a thin disc, which gradually and continually dopes the remnant atmosphere with silicon.
Dr Jay Farihi of Cambridge’s Institute of Astronomy said that the stuff must be falling on to each star at a very high rate, adding that they could calculate the number of grams per second that turned out to be something like a small river’s worth of material.
The scientists used Hubble Space Telescope to probe these two stars, deciphering their chemistry with the observatory’s powerful Cosmic Origins Spectrograph.
This showed that the dwarfs were “polluted” with silicon - the element found in the rocky material that makes up the Earth, the other inner planets in our Solar System, and its asteroids.
The work is published in the Monthly Notices of the Royal Astronomical Society.