Astronomers discovered carbon-13 isotopes in the atmosphere of an exoplanet. Credit: Daniëlle Futselaar (Artsource)

Astronomers Detect Isotopes in Distant Alien World’s Atmosphere

A massive breakthrough for astronomy and science.


Scientists from the University of Leiden in the Netherlands have studied the planet TYC 8998-760-1 b, located just over 300 light-years from Earth. Observations have shown that carbon-13 isotopes are present in its atmosphere, which have never been discovered on a planet outside the solar system in the past. The presence of such an isotope indicates that the exoplanet formed at a great distance from the parent star, beyond the boundary of the carbon monoxide snow line.

Astronomers discovered isotopes in a distant exoplanet for the first time in history

1. In 2019, astronomers discovered two large planets near the distant solar-type star TYC 8998-760-1: one is six times more massive than Jupiter, the other 14 times more massive.


2. This was one of the rare cases when exoplanets were captured directly using a VLT Telescope armed with a special “coronagraph”. That is why scientists noticed the planets, although they are at a very impressive distance from their star and would hardly have been found using transit and other traditional methods.

3. Thus, the orbit of TYC 8998-760-1 b is about 160 astronomical units which, for comparison, is four times farther than even Pluto’s orbit in the Solar System. With further observations, astronomers have classified the exoplanet as a super Jupiter, due to its unbelievable mass.

Artist's impression of the hypothetical appearance of TYC 8998-760-1 b whose atmosphere is rich in carbon isotopes. Credit: NASA Exoplanet Catalog
Artist’s impression of the hypothetical appearance of TYC 8998-760-1 b whose atmosphere is rich in carbon isotopes. Credit: NASA Exoplanet Catalog

4. Scientists used the SINFONI infrared spectrograph installed on the Very Large Telescope (VLT) in Chile and obtained the TYC 8998-760-1 b spectrum with absorption lines that indicate the presence of various substances in its atmosphere.

5. Specifically, the researchers found evidence of carbon-13, a stable but fairly rare isotope that only makes up about one percent of carbon on Earth. On TYC 8998-760-1 b, it is most likely a part of CO molecules, carbon monoxide.


6. The amount of carbon-13 turned out to be many times higher than astronomers expected. They attribute this to the great distance of the planet from the parent star: beyond the snow line of carbon monoxide – the conditional boundary beyond which the temperature is so low that this volatile compound goes into a solid-state.

Scheme of the formation of planets closer and farther than the CO snow line; shown for illustration Jupiter and Neptune and exoplanet TYC 8998-760-1 b. Credit: Yapeng Zhang, Leiden Observatory, MPIA Graphics

7. Forming in this region, TYC 8998-760-1 b collected large volumes of CO in the form of ice, and with it carbon-13 isotopes.

8. The authors note that the planets of our solar system are all much closer to the star, so we apparently do not have exact analogs of TYC 8998-760-1 b.

9. But something similar can be seen in Neptune and Uranus: the shells of these gas giants are rich in deuterium because they formed behind the snow line of water.

10. According to scientists, in the future, the study of the isotopic composition of exoplanets may become a new tool for determining the place in which they were born.

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Sources: (2021, July 14). First measurement of isotopes in atmosphere of exoplanet.
Starr, M. (n.d.). Isotopes Detected in The Atmosphere of an Exoplanet For The First Time. ScienceAlert.
Zhang, Y., Snellen, I. A. G., Bohn, A. J., Mollière, P., Ginski, C., Hoeijmakers, H. J., Kenworthy, M. A., Mamajek, E. E., Meshkat, T., Reggiani, M., & Snik, F. (2021, July 14). The 13CO-rich atmosphere of a young accreting super-Jupiter. Nature News.

Written by Vladislav Tchakarov

Hello, my name is Vladislav and I am glad to have you here on Curiosmos. As a history student, I have a strong passion for history and science, and the opportunity to research and write in this field on a daily basis is a dream come true.

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