Hot Jupiter TOI-7169 b orbits one of the oldest, most metal-poor stars

Star system: TOI-7169 | Distance from the Sun: 1478 light years

TOI-7169 b is a giant planet, known as a hot Jupiter, that orbits a star with very low metal content. Most planets are found around stars rich in elements heavier than hydrogen and helium, but TOI-7169 b challenges this trend by orbiting a metal-poor star. This discovery helps scientists understand how planets can form in environments with fewer heavy elements.

The planet was detected using data from the TESS space telescope and ground-based observations. It completes an orbit around its star every 3.44 days. Measurements show that TOI-7169 b is larger than Jupiter but has a much lower density, meaning it is inflated and has a puffy atmosphere. The host star is ancient, about 12.3 billion years old, and has a higher proportion of alpha elements compared to iron, but it still resides in the thin disk of our galaxy.

TOI-7169 b is one of the oldest and most metal-poor stars known to host a transiting giant planet. Studying its atmosphere in the future could reveal how a star's composition affects the properties of its planets, especially for giant planets like hot Jupiters.

Key findings
- TOI-7169 b is a hot Jupiter orbiting a metal-poor star
- The planet is inflated, with a low density and large radius
- The host star is ancient and alpha-enhanced
- This system challenges the idea that giant planets only form around metal-rich stars
- Future studies may reveal how metallicity shapes giant planet atmospheres

Scientific study

TOI-7169 b: A Hot Jupiter Transiting a Metal-Poor Star (external link)