For a decade there has been a factor of 2.5 gap in luminosity between the 275K WISE J085510.83-071442.5 (Luhman 2014) and all other Y dwarfs, with Teff >= 350K. Recently three objects were found which may fall in this gap.
For a decade there has been a factor of 2.5 gap in luminosity between the 275K WISE J085510.83-071442.5 (Luhman 2014) and all other Y dwarfs, with Teff >= 350K. Recently three objects were found which may fall in this gap.
![The top panel are the inner and outer HZ limits for main-sequence stars as a function of stellar mass, according to (R. K. Kopparapu et al. 2013). The bottom panel is the same but for cloudy evolution brown dwarfs. The solid lines are the inner HZ and the dashed lines are the outer HZ. The difference between objects at the hydrogen-burning threshold arises because R. K. Kopparapu et al. (2013) employed a full radiative–convective atmospheric model, whereas this study assumes a constant planetary Bond albedo of 0.25. All brown dwarfs have [M/H] = +0.0. -- astro-ph.EP](https://i0.wp.com/astrobiology.newspackstaging.com/wp-content/uploads/2026/03/The-Influence-of-Clouds-and-Deuterium.png?resize=800%2C600&ssl=1)
![[LEFT:] A Rare Brown Dwarf: HIP 71618 B [RIGHT:] A New Giant Planet: HIP 54515 b -- W. M. Keck Observatory and the Subaru Telescope.](https://i0.wp.com/astrobiology.newspackstaging.com/wp-content/uploads/2025/12/Discoveries-From-Maunakea-Reveal-1.png?resize=800%2C600&ssl=1)