Nearby solar system much like ours


New observations confirm that the Epsilon Eridani stellar system has a structure similar to our own, writes Anthea Batsakis.


Illustration of the Epsilon Eridani system showing Epsilon Eridani b.
NASA / SOFIA / Lynette Cook

A young solar system 10.5 light years away has been found to mirror our own in many ways, thanks to observations from NASA’s airborne observatory, SOFIA.

Located in the southern hemisphere of the constellation Eridanus – the setting of classic sci-fi show Babylon 5 – this system may help astronomers understand the origin of our own solar system.

The star, named Epsilon Eridani, is a similar size to the sun, though much younger, and as the closest planetary system that is similar to ours it is in a prime spot for research.

The inner and outer parts of the Epsilon Eridani system compared with the corresponding parts of our solar system.
NASA / JPL / Caltech / R. Hurt

NASA’s Spitzer space telescope had already observed that the star was circled by a debris disk – a concentration of leftover matter orbiting the sun after a planet has formed.

The largest planetary body in a solar system is often associated with a debris disk nearby, but Spitzer’s data wasn’t able to lead to a blueprint of the debris disk’s architecture.

Instead, astronomers came up with two theoretical models for what the debris disk might look like.

One model theorised the debris disk to be made of two narrow rings are roughly the positions corresponding to the asteroid belt and Uranus’ orbit in our solar system. The other model indicated a broad disk in the outer reaches of the solar system, not associated with any planets.

But the diameter of SOFIA’s telescope – 2.5 metres – is almost three times the size of Spitzer’s. It is located in an aircraft that flies through the stratosphere, which mean that, like Spitzer, it can more clearly observe infrared emissions than Earth-bound observatories.

Led by the University of Arizona’s Kate Su, the research team found the debris was more like the first model – two narrow belt-like rings. One of the rings is adjacent to a Jupiter-like planet and the other ring at a position corresponding to that of the Kuiper Belt in our solar system.

In other words, Epsilon Eridani’s planetary system reflects both the inner and outer structure of the sun’s, giving astronomers an insight into our solar system’s early years.

“A planetary mass object is needed to stop the sheet of dust from the outer zone, similar to Neptune’s role in our solar system,” Su says. “It really is impressive how Eps Eri, a much younger version of our solar system, is put together like ours.”

Their findings were published in the Astronomical Journal.

  1. http://iopscience.iop.org/article/10.3847/1538-3881/aa696b/meta
  2. http://iopscience.iop.org/article/10.3847/1538-3881/aa696b/meta
Latest Stories
MoreMore Articles