Free Astronomy Magazine September-October 2025

SEPTEMBER-OCTOBER 2025 a young star 440 light-years away, we may be watching a planet come into existence in real time,” says Francesco Maio, a doctoral re- searcher at the University of Flo- rence, Italy, and lead author of this study, published in Astronomy & As- trophysics . The potential planet-in-the-making was detected around the star HD 135344B, within a disc of gas and dust around it called a protoplane- tary disc. The budding planet is esti- mated to be twice the size of Jupiter and as far from its host star as Nep- tune is from the Sun. It has been observed shaping its surroundings within the protoplanetary disc as it grows into a fully formed planet. by ESO Bárbara Ferreira A newborn planet sculpts the dust around itself A stronomers may have caught a still-forming planet in ac- tion, carving out an intricate pattern in the gas and dust that sur- rounds its young host star. Using ESO’s Very Large Telescope (VLT), they observed a planetary disc with prominent spiral arms, finding clear signs of a planet nestled in its inner regions. This is the first time as- tronomers have detected a planet candidate embedded inside a disc spiral. “We will never witness the formation of Earth, but here, around T he image to the left, taken with ESO’s Very Large Telescope (VLT), shows a possible planet being born around the young star HD 135344B. This star, located around 440 light-years away, is surrounded by a disc of dust and gas with promi- nent spiral arms. Theory predicts that planets can sculpt spiral arms like these, and the new planet candi- date is located at the base of one of the arms, just as expected. The image was captured with a new VLT instrument: the Enhanced Resolution Imager and Spectrograph (ERIS). The central black circle corresponds to a coronagraph –– a device that blocks the light of the star to reveal faint details around it. The white circle in- dicates the location of the planet. The image to the right is a combina- tion of previous observations taken with the SPHERE instrument also at the VLT (red) and the Atacama Large Millimeter/submillimeter Array (ALMA, orange and blue). These and other previous studies of HD 135344B did not find signatures of a companion, but ERIS may have fi- nally unveiled the culprit responsible for the star’s spiral disc. [ESO/F. Maio et al./T. Stolker et al./ ALMA (ESO/ NAOJ/NRAO)/N. van der Marel et al.]