We found 'stars' that are so cold you could literally hold them in your hand—they're chillier than your morning latte.
March 27, 2026
Original Paper
The Coldest Known Y Dwarfs: Estimates of their Effective Temperatures
arXiv · 2603.24740
The Takeaway
Known as Y Dwarfs, these objects are the missing link between stars and planets. While typical stars burn at thousands of degrees, these specific objects were measured at just 275 Kelvin (around 35°F or 2°C)—meaning they are actually colder than the temperature inside a standard household refrigerator.
From the abstract
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. Two are companions to Y dwarfs: WISE J033605.05-014350.4B (Calissendorff et al. 2023) and CWISEP J193518.58-154620.3B (De Furio et al. 2025); the third is MEAD 62B, a candidate companion to a white dwarf (Albert et al. 2025). Evolutionary models calculate a tight relationship