A rare new Super-Earth planet is found towards the center of the galaxy. According to the astronomers at the University of Canterbury (UK), the planet is one of only a handful that have been discovered with both size and orbit similar as that of Earth’s.
Lead researchers in the discovery, Dr. Antonio Herrera Martin and Associate Professor Michael Albrow, both planet-hunters, are part of an international team of astronomers who collaborated on the Super-Earth research, which has recently been published in The Astronomical Journal.
The planet-finding discovery is incredibly rare, as described by the paper’s Dr. Herrera Martin, the paper’s lead author.
“To have an idea of the rarity of the detection, the time it took to observe the magnification due to the host star was approximately five days, while the planet was detected only during a small five-hour distortion. After confirming this was indeed caused by another ‘body’ different from the star, and not an instrumental error, we proceeded to obtain the characteristics of the star-planet system,” he says.
The planet was discovered using a technique called gravitational microlensing.
“The combined gravity of the planet and its host star caused the light from a more distant background star to be magnified in a particular way. We used telescopes distributed around the world to measure the light-bending effect,” Martin explains.
The microlensing effect is rare, with only about one in a million stars in the galaxy being affected at any given time. Furthermore, this type of observation does not repeat, and the probabilities of catching a planet at the same time are extremely low, the UC astronomer says.
According to the astronomers, this particular microlensing event was observed during 2018 and designated OGLE-2018-BLG-0677. It was independently detected by the Optical Gravitational Lensing Experiment (OGLE) using a telescope in Chile, and the Korea Microlensing Telescope Network (KMTNet) to which the UC astronomers belong, using three identical telescopes in Chile, Australia, and South Africa. The KMTNet telescopes are equipped with very large cameras, which the team uses to measure the light output from around one hundred million (100,000,000) stars every 15 minutes.
“These experiments detect around 3,000 microlensing events each year, the majority of which are due to lensing by single stars,” the paper’s co-author Associate Professor Albrow notes.
“Dr. Herrera Martin first noticed that there was an unusual shape to the light output from this event, and undertook months of computational analysis that resulted in the conclusion that this event was due to a star with a low-mass planet,” says Albrow. (JSM/JuanManila)
Featured image: Super-Earth, an artist’s illustration.