Astronomers Identify Earth-Sized Planet Candidate 150 Light-Years Away

An international team of astronomers, led by researchers from the University of Southern Queensland (UniSQ), has identified a candidate Earth-sized planet, HD 137010 b, situated approximately 150 light-years from Earth. The planet is estimated to be about 6% larger than Earth and orbits a Sun-like star.

The discovery was made using data from NASA's Kepler space telescope's extended K2 mission, captured in 2017. HD 137010 b was detected when it briefly transited its host star, causing a slight dimming observed over a 10-hour period. This single transit suggests an orbital period of approximately 355 days, similar to Earth's year.

Dr. Alexander Venner, who led the research during his PhD at UniSQ, first identified the potential signal as a high school student participating in the Planet Hunters citizen science project. Reflecting on the discovery, Dr. Venner stated, "I contributed to this citizen science project called Planet Hunters back when I was in secondary school, and it was a big part of how I got into research."

The planet's location places it near the outer edge of the habitable zone, where conditions might allow for liquid water under a suitable atmosphere. However, due to its star being cooler and dimmer than our Sun, HD 137010 b receives less than a third of the heat and light Earth does, potentially resulting in surface temperatures below -70 degrees Celsius.

While the initial findings are promising, further observations are required to confirm HD 137010 b as a planet. Dr. Chelsea Huang, a co-author of the study, emphasized the need for additional data, stating, "We have to wait for the development of the next generation of instruments to tell us the mass of this planet."

The research team included scientists from Australia, the United Kingdom, the United States, and Denmark. Their findings have been published in The Astrophysical Journal Letters.