The polystyrene planet
Stories from Physics
for 11-14
14-16
Astrophysicists have discovered an ‘extraordinarily inflated’ low-density exoplanet. KELT-11b has a radius around 1.4 times that of Jupiter but only about a fifth of its mass, giving it a density of only 0.09 g/cm 3, around the density of Styrofoam. KELT-11b orbits close to its parent star and has an orbital period of just five days. The parent star is in the process of expanding into a red giant and is likely to engulf its low-density satellite within a hundred million years.
References
The polystyrene planet
J. Pepper, J. E. Rodriguez, K. A. Collins, J. A., Johnson, B. J. Fulton, A. W. Howard, … & M. B. Lund, M. B. (2016). KELT-11b: A Highly Inflated Sub-Saturn Exoplanet Transiting the V= 8 Subgiant HD 93396. 2016, The Astronomical Journal, vol. 153, no. 5, 2016, pp. 1-15
L. Spiegel, Giant ‘Styrofoam’ Planet Could Help Scientists Find New Habitable Worlds, Huffington Post Website, 25th May 2017, http://www.huffingtonpost.com/entry/styrofoam-exoplanet-lehigh-university_us_592463dae4b03b485cb58b5c
