There is a planet called HD 80606 b, which is home to some of the most extreme changes in temperature. As it races around its star, conditions on the planet change so quickly and intensely that scientists can watch its atmosphere transform in real time.
Thanks to new observations made by the NASA’s James Webb Space Telescope, scientists can study this extraordinary planet even further.
According to these observations, the planet is much hotter than previously thought during the period of its closest approach to the star.
A planet unlike most hot Jupiters
HD 80606 b belongs to a group of planets known as hot Jupiters.
Hot Jupiters are giant gas planets like Jupiter, but they orbit extremely close to their stars, giving them exceptionally high temperatures.
Most hot Jupiters follow relatively circular orbits. HD 80606 b does not.
Instead, the planet follows a highly elongated orbit that carries it far from its Sun-like star before sending it plunging back in.
This cycle repeats once every 111 days. At its closest approach, known as periastron, the planet receives a tremendous amount of energy from its star.
“Hot Jupiters are already considered some of the most extreme exoplanets we know of, but even among that population, HD 80606 b is one of the most extreme,” said Tiffany Kataria, the study’s principal investigator at NASA’s Jet Propulsion Laboratory.
“We typically think of hot Jupiters as hot gas giants sitting right next to their stars, but this planet’s highly eccentric orbit creates a completely different beast.”
Temperature jumps that surprised scientists
The James Webb Space Telescope observed HD 80606 b before, during, and after its closest encounter with its star.
The telescope’s instruments revealed that the planet’s temperature shoots upward by about 1,100 degrees Fahrenheit during this period.
That sudden heating can dramatically alter the planet’s atmosphere. Previous studies have shown that rapid temperature changes can affect cloud formation and trigger shifts in atmospheric chemistry.
Researchers specifically used Webb’s Mid-Infrared Instrument, known as MIRI, to track these changes. Infrared observations are especially useful because they allow scientists to measure heat and identify different molecules in a planet’s atmosphere.
“Webb has shown that the planet’s increase in temperature was even more extreme than we anticipated based on Spitzer data,” said Kataria.
Why this strange planet matters
Scientists are interested in HD 80606 b not only because it is unusual, but because it allows them to study several atmospheric conditions within a very short period.
Many exoplanets require years of observations to understand how their atmospheres behave. HD 80606 b compresses a wide range of conditions into just a few hours as it swings close to its star.
Researchers said HD 80606 b is an ideal planet to study because of its unusual orbit. As it moves around its star, its temperature changes dramatically. Its atmospheric chemistry shifts just as quickly.
That lets scientists collect data under many different conditions in only a few hours. They can then use those findings to better understand other hot Jupiters and even more conventional exoplanets.
This artist’s concept shows exoplanet HD 80606 b being “roasted” as its orbit approaches periastron, the point at which it is closest to its host star, which is similar to our Sun. Credit: NASA, ESA, CSA, Joseph Olmsted (STScI). Click image to enlarge.Reading a planet through light
To study the atmosphere, researchers relied on spectroscopy, a technique that breaks light into its component colors. Scientists use this method throughout astronomy because different chemicals leave distinct fingerprints in light.
Spectroscopy can reveal a planet’s temperature, movement, chemical makeup, and other physical characteristics. It has become one of the most powerful tools for investigating worlds that are too distant to visit directly.
During the observation period, HD 80606 b also moved behind its star from Webb’s point of view, creating what astronomers call a secondary eclipse.
Events like this help researchers separate the planet’s light from the star’s light and improve atmospheric measurements.
Building on years of work
The recent observations were not a quick project. Researchers spent years planning the timing because the planet’s unusual orbit and Webb’s viewing constraints made scheduling difficult.
The work also builds on earlier observations from NASA’s Spitzer Space Telescope, which retired in 2020. Spitzer first revealed that HD 80606 b was an especially promising target for infrared studies.
The planet even earned the nickname “roasted exoplanet” because of its extreme heating.
“Spitzer did amazing work on this exoplanet,” said Ryan Challener, co-author and research associate at the Cornell Center for Astrophysics and Planetary Science. “Now, Webb is building on that legacy by enabling us to drill down and distinguish specific chemical signatures like methane and carbon dioxide, which is just amazing progress.”
Researchers are still analyzing the enormous amount of information collected by Webb. The early results show a world pushed to remarkable limits, and scientists believe the dataset may reveal much more about how giant planets evolve under intense conditions.
“There’s so much to learn from this one dataset. We really are just getting started deciphering what Webb has to tell us.”
—–
Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.
Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.
—–