Question 1

True or false: This planet completes one orbit around its star every 3.5 Earth days.

Accepted Answer

True. HD 209458 b is a hot Jupiter with an orbital period of just 3.52 days, extremely close to its star.

Question 2

True or false: The planet's temperature is cooler than any planet in our solar system.

Accepted Answer

False. It’s a hot Jupiter with surface temperatures around 1,000°C, far hotter than any solar system planet.

Question 3

True or false: HD 209458 b has a solid, rocky surface like Earth.

Accepted Answer

False. It’s a gas giant with no solid surface, composed mainly of hydrogen and helium.

Question 4

True or false: HD 209458 b orbits a red dwarf star much smaller than the Sun.

Accepted Answer

False. Its host star, HD 209458, is a G-type star similar to our Sun, not a red dwarf.

Question 5

True or false: HD 209458 b was discovered using direct imaging from ground telescopes.

Accepted Answer

False. It was discovered via the transit method in 1999, not direct imaging, which came later for other planets.

Question 6

True or false: HD 209458 b was the first exoplanet observed to have an atmosphere.

Accepted Answer

True. In 2001, Hubble detected sodium in its atmosphere, marking the first direct detection of an exoplanet's atmosphere.

Question 7

True or false: Water vapor was detected in the atmosphere of HD 209458 b in 2007.

Accepted Answer

True. Spitzer Space Telescope found water vapor in its infrared spectrum, a surprising early detection.

Question 8

True or false: HD 209458 b is losing its atmosphere due to intense stellar radiation.

Accepted Answer

True. It's a 'bloated' planet; hydrogen is evaporating at high speed, forming a comet-like tail.

HD 209458 b Trivia Questions