Dra'a Omoa, an associate professor of physics and astronomy at the University of California, Irvine, led this amazing study. This study shows how some planets around dead stars, called white dwarfs, can support life! 🪐
By Steve Zellius/ University of California, Irvine
- Are white dwarfs habitable? 🤔 White dwarfs are the hot, dense cores of dead stars. Astronomers thought that planets orbiting them wouldn't be habitable, but it turns out the opposite is true!
- Fast-moving planets are warmer: 💨 A new study shows that planets orbiting white dwarfs at high speeds, in smaller orbits, are warmer than previously thought, and possibly habitable!
Is our Milky Way galaxy teeming with planets? Absolutely! Astronomers have found planets around all sorts of stars, from sun-like stars to red dwarfs, and even white dwarfs, the cores of dead stars. And now, new research suggests that some of these planets might even be habitable!
On February 13, 2025, the University of California, Irvine announced that white dwarfs may host habitable planets. The secret? The rotational speed of these worlds. 🚀
What is habitability? It doesn't mean we can live there! Rather, it means that the physical conditions on the planet allow for life, whether bacterial or otherwise. Learn more about the concept of habitability .
A study conducted by Omoa Shields and her team was published in The Astrophysical Journal on January 16, 2025. 🔬 Link to the study
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climate comparison
Researchers compared a planet around a hypothetical white dwarf star to a planet around a sun-like star, Kepler-62, using a complex digital model of planetary climates. The model compared hypothetical planets in each star's habitable zone, where temperatures are suitable for liquid water.
Although white dwarfs emit heat from residual nuclear activity, the planet orbiting the white dwarf in the simulation was warmer—and potentially more habitable—than the planet around Kepler-62. This is due to one important factor…
Orbital speed: key to residential
The key to habitability lies in how close a planet is to its star. The habitable zone is defined differently for each star. A planet orbiting a white dwarf is closer to its star, resulting in a faster orbital speed. 🪐
Our planet Mercury, the closest to the Sun, rotates very quickly. But the planet orbiting the white dwarf takes only ten hours , while Kepler-62 takes 155 days! ⏱️
Furthermore, both planets are tidally locked, meaning they always face the same direction towards their star. Therefore, this synchronized rotation affects the planet's climate.
Speed leads to enormous variations in the atmosphere. On Kepler-62, clouds accumulate on the constantly sunlit side, cooling the planet. The planet orbiting the white dwarf has less cloud cover and is generally warmer. ☁️🔥
This research suggests that the environment of white dwarfs, previously considered unsuitable for life, may offer new insights for planetary scientists and astrobiologists. 👽🔭
Last year, we got our first possible images of giant planets orbiting white dwarfs! Also, scientists found evidence that white dwarfs are devouring Earth-like planets! 🔥
Summary: Fast-moving planets around white dwarfs may be habitable! 🚀
Source: Original article