Astronomers usually confirm new exoplanets a few at a time — maybe five or ten in a single announcement. Today, researchers from the University of Tokyo have certified a whopping 44 new exoplanets in a single go. The planets mostly orbit close to their host stars, and they tend toward the larger end of the scale. However, there are a few that are Earth-size and smaller.
Forty-four exoplanets might not sound like a lot at first. After all, we often talk about how NASA’s Kepler satellite has recorded hundreds of exoplanet signals during its most recent observation. However, these are just potential exoplanets. It’s up to humans to comb through that data and decide what is and is not a planet. Although, Google has demonstrated that AI can help with that.
All the planets in the latest batch come from the Kepler K2 mission’s 10th campaign. They’re what are known as transiting planets, meaning they pass in front of their host stars. Kepler watches for small periodic dips in brightness that can indicate the presence of an exoplanet. Other events and objects can cause similar drops in brightness, but it’s not up to the satellite to assess that. Kepler just gathers all the data it can and sends it back to Earth for analysis.
The researchers used additional observations from the European Space Agency (ESA) Gaia space telescopes as well as ground-based telescopes in the US to check all the notable signals from campaign 10 in 2016. The team whittled down the list of potential planets to end up with the final list of 44 confirmed new planets.
Transit detection of exoplanets only works when the plane of the solar system is roughly aligned with ours. Larger planets and those with shorter orbital periods are also easier to detect. In addition to size and orbital characteristics, the researchers were able to determine the temperature of most exoplanets.
Four of the planets have orbits of less than 24 Earth hours. We used to think these ultrashort-period exoplanets were rare, but that may not be the case. More interestingly, the Kepler data also included some small, rocky planets. According to the study, 16 of the new planets are in the same class as Earth. There’s even one planet that’s very similar to Venus, which is a bit smaller than Earth.
Kepler is winding down, but we still have data from several more observational campaigns to analyze. The Transiting Exoplanet Survey Satellite (TESS) is also up and running now, and it should provide new exoplanet finds for years to come.
Now read: Astronomers Spot Nearly 80 Exoplanets in Record Time, NASA’s TESS Spacecraft Captured Amazing Footage of a Comet During Testing, and The ‘Alien Megastructure Star’ Enters Another Dimming Phase