Researchers call for armchair astronomers to help find unknown hidden worlds
Astronomers have launched a new online initiative, calling for volunteers to come forward and help to search for planets beyond our Solar System.
The online citizen project, Planet Hunters Next-Generation Transit Survey (NGTS), is enlisting the help of the public to examine five years’ worth of digital footage showing the brightest stars in the sky.
The footage was captured by 12 NGTS robotic telescopes based at the European Southern Observatory (ESO) Paranal Observatory in Chile – they make high precision measurements, sensitive enough to detect the signatures of exoplanets.
Leicester is a key partner of the NGTS, which is a collaboration between Queen’s University Belfast, the University of Warwick, University of Cambridge, University of Leicester, Geneva Observatory, German Aerospace Center, Universidad de Chile, the Universidad Católica del Norte, and the European Southern Observatory.
Dr Sarah Casewell is an STFC Ernest Rutherford Research Fellow based at the University of Leicester, and will lead Leicester’s contribution to the project. She said:
“This is the second citizen science project I am involved in, and I’m so excited to be part of the project and to see what our citizen scientists discover. In my experience their enthusiasm for the science and their discoveries is infectious, and that makes citizen science projects such fun to be a part of.
“The benefit of the human eye over computers is that people pick out objects they think are interesting, and this is how we find the most unusual objects. These may not be planets, but other interesting binaries, or active stars – the possibilities for interesting discoveries out of these data is just endless!”
Dr Meg Schwamb, of Queen’s University Belfast, is leading the project. She said:
“If the orbit of an exoplanet is seen at just the right angle from Earth, we may observe the planet passing directly in front of its host star, known as a transit. This causes the planet to periodically block a portion of the starlight we observe, and the star appears to dim ever so slightly for a few hours.
“Every 10 seconds, the NGTS telescopes capture the light from thousands of stars in the sky looking for the tell-tale signatures of an exoplanet transit.
“Computers are searching through the NGTS observations looking for the tell-tale repeated dips in starlight due to planet transits. The automated algorithms produce lots and lots of possible candidate transit events that need to be reviewed by the NGTS team to confirm whether they are real or not.
“Most of the things spotted by the computers are not due to exoplanets, but a small handful of these candidates are new bona fide planet discoveries.”
While the NGTS team reviews the most interesting objects identified by computers, humans are still better at picking out the signals of transiting planets – and the team thinks there may still be planets lurking in the data that the computers missed.
Volunteers are encouraged to help sift through these flagged observations, to possibly discover hidden exoplanets not found at first review. While the project team expect most exoplanets in the data have already been discovered – more than 20 to date – volunteers may be the first to find brand new worlds orbiting another star in our Galaxy.
Discoveries so far include NGTS-4b, the so-called ‘impossible planet’ around the size of Neptune but orbiting much closer to its host star, and NGTS-1b; a rare ‘hot Jupiter’ orbiting a red dwarf.
Leicester PhD student Jack Acton led research which, using NGTS data, identified a brown dwarf with a mass of around 69 times that of Jupiter. NGTS-19b was discovered transiting another star, similar to an exoplanet. Jack said:
“NGTS-19b is one of only a handful of transiting brown dwarfs to have been discovered. We know of thousands of transiting exoplanets but only a few tens of transiting brown dwarfs. The lack of these objects is usually referred to as the “Brown Dwarf desert”, and understanding this phenomenon allows for insight into the formation and evolution of all sorts of planetary systems.
“We don’t really know if these objects are actually rare, or if we just haven’t found many of them yet! Planet Hunters NGTS offers us another chance to find more of these important and interesting systems, as well as the opportunity to discover previously unknown planets! I’m really looking forward to seeing what exciting things people discover in NGTS data.”
There is no application process to join the Planet Hunters NGTS project. Anyone with a web browser can dive right into the data and start searching for these possible hidden worlds and helping to check the best candidate planets identified on the website.
For more information, visit ngts.planethunters.org.