Astronomers using the Gemini Planet Imager at the Gemini South telescope in Chile have identified a disc-shaped bright ring of dust around a nearby young star called HD 115600.
Images of HD 115600 showing a bright nearly edge-on debris ring located just beyond a Pluto-like distance to the star. Image credit: Thayne Currie et al.
HD 115600 is located in the constellation Centaurus, approximately 360 light-years away.
The star is a member of the massive 10-20 million year-old Scorpius-Centaurus OB association, a region similar to that in which the Sun was formed.
The debris disc around HD 115600 is located between about 37 and 55 AUs (3.4 – 5.1 billion miles) from the star, which is almost the same distance as the Solar System’s Kuiper Belt is from the Sun.
Its brightness, which is due to the starlight reflected by it, is also consistent with a wide range of dust compositions including the silicates and ice present in the Kuiper Belt.
HD 115600’s disc is not perfectly centered on the star, which is strong indication that it was likely sculpted by one or more unseen planets.
By using models of how planets shape a debris disc, the astronomers led by Dr Thayne Currie of the Subaru Observatory in Hawaii found that ‘eccentric’ versions of the giant planets in the outer Solar System could explain the observed properties of the ring.
“It’s almost like looking at the outer Solar System when it was a toddler,” said Dr Currie, lead author of the paper reporting the results in the Astrophysical Journal Letters (arXiv.org preprint).
The current theory on the formation of our Solar System holds that it originated within a giant molecular cloud of hydrogen, in which clumps of denser material formed.
One of these clumps, rotating and collapsing under its own gravitation, formed a flattened spinning disc known as the Solar Nebula.
The Sun formed at the hot and dense center of this disc, while the planets grew by accretion in the cooler outer regions. The Kuiper Belt is believed to be made up of the remnants of this process, so there is a possibility that once the new system develops, it may look remarkably similar to our Solar System.
“Our discovery of a near-twin of the Kuiper Belt provides direct evidence that the planetary birth environment of the solar system may not be uncommon,” said co-author Dr Nikku Madhusudhan from the University of Cambridge’s Institute of Astronomy.
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Thayne Currie et al. 2015. Direct Imaging and Spectroscopy of a Young Extrasolar Kuiper Belt in the Nearest OB Association. ApJ Letters, in press; arXiv: 1505.06734
