What have scientists at the University of Galway discovered this week?
They have found a baby exoplanet – a baby in chronological terms, but not in terms of size.
What is an exoplanet?
An exoplanet is a planet orbiting around another sun. They were first discovered in 1995. Since then thousands of them have been detected. There are countless billions of them in the universe. The holy grail for astronomers is to find a planet like our own in the so-called “Goldilocks zone”, where it is neither too hot nor too cold for life.
What have the scientists found?
The romantically named WISPIT 2b was discovered orbiting a new star 430 light years away in the constellation of Aquila. WISPIT 2 is a young star, which has just been formed.
Astronomers know this because it is surrounded by a multiringed disk known as a protoplanetary disk. This is material left over after a star is formed. The planets in our solar system emerged from the birth of our sun six billion years ago.
The significance of this discovery is that astronomers were able to see within this disk a planet being formed. The planet in question is a gas giant like our Jupiter or Saturn, but is many times bigger. The astronomers liken the discovery to a prehistoric time machine where one can watch the birth of a solar system like our own.
[ New ‘exceptionally beautiful’ planet discovered by Irish astronomersOpens in new window ]
How was it discovered?
Observing exoplanets is exceptionally difficult. They emit no light of their own and can usually only be detected by blocking out the light from the sun around it.
The ground-breaking discovery was made using one of the world’s most advanced observatories – the European Southern Observatory’s Very Large Telescope (ESO’s VLT) in the Atacama Desert in Chile.
The teams at Galway, Leiden University in the Netherlands and the University of Arizona took multiple photographs of the star in question to see if they could detect light reflecting from an exoplanet.
Instead they found the multiringed, multicoloured dust disk. The disk is huge stretching to 380 astronomical units (380 times the distance of the Earth from the Sun) or 5.7 trillion kilometres.
The astronomy world was amazed as this phenomenon had been detected but never seen before.
How have astronomers reacted?
Chloe Lawlor, a doctoral student at the University of Galway, summed up the excitement: “WISPIT 2b, with its position within its birth disk, is a beautiful example of a planet that can be used to explore current planet formation models. I am certain this will become a landmark paper.”
The planet was captured in near infrared light – the type of view that someone would see when using night-vision goggles – as it is still glowing and hot after its initial formation phase.