Dust to dust: a disintegrating rocky exoplanet could unlock secrets to how our solar system was formed

Exoplanet KIC 1255 b orbits its parent star followed by a comet-like dust tail.

Credit: Artists impression by Maciej Szyszko)

Exciting new research has opened up the chance to find out what distant planets are made of. A team of astronomers from The Open University (OU) and the Universities of Warwick and Sheffield, has made observations which can help reveal the chemical makeup of a small rocky world orbiting a distant star about 1500 light years away from Earth, increasing our understanding of how planets, including ours, were formed.

Using an advanced, ultra-fast camera known as ULTRACAM, located on the William Herschel Telescope (WHT), part of the Isaac Newton Group of Telescopes (ING) in the Canary Islands, the researchers have observed an extraordinary exoplanet named ‘KIC 1255 b’. The ING is owned by STFC and is operated in collaboration with the Netherlands and Spain.

"A single year on KIC 1255b lasts only 16 hours on Earth and the whole planet seems to be slowly boiling away under intense heat of its sun" said Jakub Bochinski, research student at the OU, and lead author of the study.

The planet’s surface is heated to over 2100K (over 1800°C), hot enough to vaporise rock. As a result, the planet’s outer layers are continuously destroyed, with the evaporating rock creating a comet-like dust tail following the planet in its orbit.

The ULTRACAM measurements were the most sensitive yet made, and revealed that the dust cloud, when visible, blocks a slightly larger fraction of the star’s blue light than red light. A similar effect is seen at sunset on Earth when the Sun’s light is scattered by dust in the Earth’s atmosphere, making the remaining light appear reddened. The exact colour-dependence of the scattering by dust (measured by carrying out simultaneous, multi-colour measurements with ULTRACAM) can reveal the size and composition of the dust grains. Ultimately, a series of measurements of KIC 1255b’s dust cloud could reveal the chemical composition of the dust.

Since the dust is made from the rocky surface of the disintegrating planet, the same technique will allow the chemical makeup of the planet’s surface to be measured.

The research was funded by STFC.  

More Information

Marion O'Sullivan
STFC Press Office
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Notes for editors:

1. The full press release and image is available from the Open University website.
2. The paperDirect evidence for an evolving dust cloud from the exoplanet KIC12557548 bis published in The Astrophysical Journal Letters.
   
   
3. ULTRACAM is an ultra-fast, triple-beam CCD camera designed to study astrophysics on the fastest timescales. The instrument was designed and built by a consortium including Professor Dhillon from the University of Sheffield, Professor Tom Marsh from the University of Warwick and the Science and Technology Facilities Council (STFC’s) UK Astronomy Technology Centre

Source: Science and Technology Facilities Council (STFC)