The number of planetary systems discovered seems to grow on a daily basis, but most of them are wildly different to our own solar system. Now a team of University of Arizona researchers led by Kate Su have used NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA) flying observatory to take a closer look at a system 10.5 light years away and discovered it has a familiar general structure.
The star in question is Epsilon Eridani (ε Eri) in the southern hemisphere of the constellation of Eridanus. Its previous claims to fame were as the setting for the sci fi television series Babylon 5 and the disputed location of Star Trek's planet Vulcan. It's also been the subject of several early studies seeking extrasolar planets and was even monitored in the 1960s by Project Ozma as a possible source of extraterrestrial intelligence.
Previously, Epsilon Eridani was found to have a debris disk made of gas, dust, and perhaps asteroids circling it, as well as a planet with about the mass of Jupiter and orbiting the young star at a comparable distance to that which the gas giant orbits the Sun.
None of this is very remarkable by today's standards, but when Su's team examined images from SOFIA, a different story emerged. SOFIA is a 100-in (2.5-m)-diameter telescope mounted inside a Boeing 747SP jetliner that operates out of NASA's Armstrong Flight Research Center's Hangar 703, in Palmdale, California.
Much of the previous work on Epsilon Eridani involved the Spitzer Space Telescope, but SOFIA is over twice the size of Spitzer, has three times the resolution, and can operate in the infrared at wavelengths between 25 and 40 microns. What this meant was that SOFIA could discern much smaller details, especially from warm materials, than before, which suggested an alternative model to the one provided by Spitzer's data.
What the University of Arizona scientists found was that Epsilon Eridani's inner system is clear of debris with a narrow debris ring just inside the orbit of the Jupiter-like planet. Beyond this is another clear region with another debris ring about where Neptune would be in our solar system. In other words, it's a lot like the inner Solar System, asteroid belt, Jupiter, the outer Solar System and the Kuiper Belt.
"The high spatial resolution of SOFIA combined with the unique wavelength coverage and impressive dynamic range of the FORCAST camera allowed us to resolve the warm emission around eps Eri, confirming the model that located the warm material near the Jovian planet's orbit," says Su. "Furthermore, 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. It really is impressive how eps Eri, a much younger version of our solar system, is put together like ours."
The research was published in the Astronomical Journal.
Source: NASA