A giant gas planet – up to fifty times the mass of Jupiter – may be orbiting a star more than a thousand light years away from Earth. This phenomenon could explain why stellar eclipses were observed in this area of the sky in 2008 and 2011.
PDS 110 is a young star in the Orion OB1 stellar association – a grouping of several dozen hot giant stars. it is slightly larger than our sun and about the same temperature.
Scientists had noticed that the light from this rare young star was periodically blocked by a large object but they didn't know what was causing these apparent stellar eclipses.
In a study now published in the Monthly Notices of the Royal Astronomical Society, researchers led by Hugh Osborn from the University of Warwick hypothesise that these eclipses are caused by a yet undiscovered exoplanet circling PDS 110.
To come up with these findings, the scientists used data from the Wide Angle Search for Planets (also known as WASP, the UK's leading extra-solar planet detection programme) and Kilodegree Extremely Little Telescope (KELT).
This allowed them to retrace and analyse 15 years of PDS 110's activity. They found that that about every 808 days, the light from the star deemed by about 30% for about two to three week. In November 2008 and January 2011, two of these stellar eclipses were particularly visible.
"What's exciting is that during both eclipses we see the light from the star change rapidly, and that suggests that there are rings in the eclipsing object, but these rings are many times larger than the rings around Saturn," says Leiden astronomer Matthew Kenworthy who worked with Osborn on the study.
The characteristics of these stellar eclipses are consistent with transits by an unseen giant gas planet or brown dwarf with large dust rings encircling it.
If such an orbiting planet is indeed responsible for the dimming of of PDS 110's light, the next eclipse is predicted to happen in September 2017. The scientists will be carefully monitoring the star at that time for any sign of the phenomenon, in the hope of collecting more data and confirming the presence of the giant gas planet.
"September's eclipse will let us study the intricate structure around PDS 110 in detail for the first time, and hopefully prove that what we are seeing is a giant exoplanet and its moons in the process of formation," Osborn said.
The researchers also point out that moons could be forming in the habitable zone around PDS 110 – which would mean that life can potentially thrive in this system. After September, more research on this issue will also be conducted.