Rare Jupiter-sized planet found ‘grazing’ distant star system

18 Dec 2017

Image: Ezume Images/Shutterstock

A new survey of a patch of deep space has found a planet about the size of Jupiter that only ‘grazes’ its star system.

With the advent of powerful telescopes such as NASA’s Kepler, the number of confirmed exoplanets has ballooned to more than 2,000. However, few discovered are like the one identified as part of the recent Qatar Exoplanet Survey (QES).

In a paper published online, a team working as part of the survey revealed a planet dubbed Qatar-6b, which ‘grazes’ its star system, meaning it only partially transits the host star’s disc.

Such planets are considered very important for researchers, as they offer a great opportunity to find additional bodies orbiting their host stars. This is because other as-yet-undetected objects would perturb the grazing planet’s orbit and could potentially induce periodic variations of the transit impact parameter, leading to transit duration variations.

Analysis of Qatar-6b has shown it to have a radius about 6pc larger than Jupiter, and a mass of about 0.67 Jupiter masses.

A ‘hot Jupiter’

The exoplanet orbits its parent star every 3.5 days at a distance of about 0.04 astronomical units (average distance from Earth to the sun) from the host, which gives it a rather sweltering equilibrium temperature of more than 700C.

This makes Qatar-6b a ‘hot Jupiter’, which is an exoplanet similar in characteristics to the solar system’s biggest planet, with orbital periods of less than 10 days and high surface temperatures.

One recent hot Jupiter discovery included Kepler-13Ab, where titanium oxide is carried around the planet by powerful winds, which causes ‘sunscreen’ to snow down.

Qatar-6 – this latest discovery’s parent star – is located 330 light years away from Earth, with a radius about 72pc of our own sun, and about 18pc less massive.

It is also something of a youngster in the universe, with estimates putting it at around 1bn years old.

Given its possible importance, future surveys using QES will be carried out with the aim of detecting variations in the transit impact parameter and duration.

The research team’s lead investigator, Khalid Al Subai, said of the future surveys: “These would require high-cadence and high-photometric-accuracy observations that could be achieved with large ground-based telescopes and/or space-based facilities.”

The news comes a few days after NASA announced that, using artificial intelligence, it had discovered our solar system’s ‘twin’, the only other system confirmed to have eight planets.

Colm Gorey was a senior journalist with Silicon Republic