Recently, astronomers have been finding protoplanetary discs around certain stars. Their discovery has helped kick off a new work in planetary formation theory. But planets aren’t the objects that form from discs of material in space. Moons do too. Now, scientists led by Dr. Tomas Stolker of Leiden University and his team have delved deeper into the characteristics of a “protolunar” disc surrounding a “super JupiterJupiter is the largest planet in the solar system and the fifth planet from the sun. It is a gas giant with a mass greater then all of the other planets combined. Its name comes from the Roman god Jupiter.”>Jupiter” exoplanetAn exoplanet (or extrasolar planet) is a planet that is outside the Solar System, orbiting around a star other than the Sun. The first suspected scientific detection of an exoplanet occurred in 1988, with the first confirmation of detection coming in 1992.”>exoplanet about 500 light-years away.
The planet, GQ Lupi B, orbits its parent star on a path about 20 times wider than Jupiter does from the Sun. In addition, the planet is much heavier than our latest gas giant. Initially discovered in 2004, this exoplanet has been the center of lots of attention. Scientists have been trying to determine whether it was formed via a typical planetary formation process, which would indeed create a giant planet. Alternatively, it could have formed using a process similar to some star and wound up as an object known as a brown dwarf.
This increased interest has led to more data on GQ Lupi B. Dr. Stolker and his team collected some of that data using two instruments on the Very Large TelescopeThe Very Large Telescope array (VLT) is a visible and infrared wavelength telescope facility operated by the European Southern Observatory on Cerro Paranal in the Atacama Desert of northern Chile. It is the world’s most advanced optical instrument, consisting of four Unit Telescopes with main mirrors of 8.2m diameter and four movable 1.8m diameter Auxiliary Telescopes.”>Very Large Telescope – NACO, a near-infrared imager, and MUSEThe Multi Unit Spectroscopic Explorer (MUSE) is a panoramic integral-field spectrograph on ESO’s Very Large Telescope in Chile. It operates in the visible wavelength range and helps astronomers reveal objects that cannot be found in imaging surveys.”>MUSE, a visible light spectroscope. Using NACO, the team took a look at the thermal profile of the disc surrounding GQ Lupi B. The surrounding disc is a much lower temperature than the planet’s atmosphere, leading the researchers to theorize that there might be a “cavity” in the ring where a moon is starting to coalesce. But it could also just be influenced by the magnetic field of the planet itself.
MUSE provided a different picture. With it, the researchers looked at H-alpha radiation, which allowed them to detect features in the planet’s atmosphere. They noticed that the planet is still growing, using either a supply of material from its own protolunar disc or grabbing material from its star’s protoplanetary disc.
Despite all the attention it has garnered, the study of GQ Lupi B still lacks a key component – the mid-infrared range. Those spectra would help astronomers understand the thermal properties of the disc and determine whether a moon indeed is forming there. Luckily, that wavelength is exactly what the James Webb Space Telescope hopes to begin monitoring soon. Unfortunately, the researchers will have to get in line to get time on the telescope, as it will be in extraordinarily high demand after numerous delays and cost overruns. But once it is fully operational, it should collect some additional light from this interesting system – and maybe even capture an image of an exomoon or two.
Originally published on Universe Today.