Discovery of a Giant Planet Candidate around a Nearby White Dwarf

The MIRI Exoplanets Orbiting White Dwarfs (MEOW) Survey has reported significant findings regarding a potential giant planet candidate orbiting a nearby white dwarf, WD 0310-688. This white dwarf is notable for being metal-polluted and is located approximately 10.4 parsecs away, making it the closest known white dwarf with a planet candidate.

The survey utilized mid-infrared observations from the James Webb Space Telescope (JWST) to detect an excess of infrared radiation at wavelengths of 18 and 21 microns. The authors of the study, including Mary Anne Limbach and 18 co-authors, assert that the source of this infrared excess is likely within the system itself, with a background contamination probability of less than 0.1%.

The findings suggest that the infrared excess could be attributed to a cold debris disk or, more likely, a giant planet with a mass of approximately 3.0 Jupiter masses and a temperature around 248 Kelvin. This planet is believed to be located within a region known as the forbidden zone, where planets are typically expected to be destroyed during the red giant phase of their host star.

The orbital separation of this candidate planet is constrained to between 0.1 and 2 astronomical units (AU) from the white dwarf. This discovery marks the first identification of a planet candidate around a white dwarf within this range of separations. Future observations with the JWST may help to confirm the presence of an atmosphere around the planet by detecting specific spectral features.

The implications of these findings are significant for our understanding of planetary formation and survival in extreme environments, particularly around white dwarfs. The study has been accepted for publication in the Astrophysical Journal Letters and can be cited as follows: Limbach, M. A., Vanderburg, A., Venner, A., Blouin, S., Stevenson, K. B., MacDonald, R. J., Jenkins, S., Bowens-Rubin, R., Soares-Furtado, M., Morley, C., Janson, M., Debes, J., Xu, S., Kleisioti, E., Kenworthy, M., Butler, P., Crane, J. D., Osip, D., Shectman, S., & Teske, J. (2024). The MIRI Exoplanets Orbiting White Dwarfs (MEOW) Survey: Mid-Infrared Excess Reveals a Giant Planet Candidate around a Nearby White Dwarf. arXiv:2408.16813.