While the Goldilocks planets I’ve written about before are still possible, recent news indicates that some of the ‘signs’ of Goldilocks planets could just be events happening within the star itself.
Scientists at Penn State University have proved that signals thought to indicate two Goldilocks planets orbiting a star are actually a result of magnetic events happening in the centre.
Gliese 581, a star with less mass than our Sun and only 20 light years from Earth, has long given off signals that two of its five planets were at just the right orbit distance to hold liquid water, a key condition in being able to support life. However, the team of scientists have now confirmed that Gliese 581 has only three planets orbiting it.
Exoplanets are detected by looking at ‘Doppler shifts’ of the light coming from a planet. A slight change in the Doppler shift could indicate that the star’s velocity is being affected by an orbiting planet, indicating the size and orbit distance of the planet. However, the light coming from the star can also be affected by activity in its centre.
The team analysed the light carefully, confirming the existence of three planets when the possibility of magnetic activity was included – but the final two planets were indistinguishable from any core activity.