HAT-P-70b’s atmosphere shows metal signatures and dynamic winds

Star system: HAT-P-70 | Distance from the Sun: 1038 light years

HAT-P-70b is an ultra-hot Jupiter, a type of giant planet that orbits very close to its star and experiences extreme temperatures. The dayside of HAT-P-70b is so hot that many metals become ionized, while the nightside remains cool enough for some elements to condense. Using the MAROON-X high-resolution spectrograph, researchers studied the planet’s atmosphere and detected fourteen different metals, including iron, titanium, calcium, chromium, sodium, vanadium, manganese, nickel, magnesium, barium, oxygen, and strontium. There is also tentative evidence for hydrogen, cobalt, and potassium.

The absorption signals from these metals show blueshifts, which means that winds are blowing from the hot dayside to the cooler nightside. The study also used atmospheric models to estimate how much of each element is present. The results show that the way scientists model the atmosphere, especially how they account for ionization and chemical reactions, can strongly affect the measured abundances. For example, not considering ionization can lead to incorrect estimates for elements like calcium and titanium. The study found that HAT-P-70b has more nickel than expected, a trend seen in other ultra-hot Jupiters as well.

These findings highlight the importance of including detailed physical and chemical processes in models when interpreting the atmospheres of extremely hot exoplanets. Understanding these processes helps scientists learn more about how such planets form and evolve.

Key findings
- Fourteen metals detected in HAT-P-70b’s atmosphere, with evidence for more.
- Blueshifted signals indicate strong day-to-night winds.
- Elemental abundances depend on how ionization and chemistry are modeled.
- Nickel is enriched compared to solar values.
- Accurate models are needed to interpret ultra-hot Jupiter atmospheres.

Scientific study

HAT-P-70b through the Eyes of MAROON-X: Constraining Elemental Abundances of Metals and Insights on Atmosphere Dynamics (external link)