the.com/cold neptune
a gas giant that showed up to the exoplanet party wearing the wrong temperature.
means a neptune-sized exoplanet that orbits far enough from its star to stay cold, unlike its scorched hot-neptune cousins.
from named by astronomers extending the hot jupiter/hot neptune naming logic outward, once wide-field surveys and radial velocity data started turning up neptune-mass worlds parked in distant, chilly orbits instead of hugging their stars.
temperature rangeoften below -200 celsius at cloud tops
rarityfar fewer confirmed than hot neptunes
detection methodmostly radial velocity, not transits
composition guessice and gas, like a slow-cooked uranus
for instance
gj 3512 b — cold neptune-mass planet around a tiny red dwarf, 2019 discovery
hd 95086 c — candidate cold neptune imaged in a young multi-planet system
wolf 1061c region — nearby red dwarf system hosting candidate cold, distant neptunes