Comparison of the dayside temperature of TRAPPIST-1 b as measured using Webb’s Mid-Infrared Instrument (MIRI) to computer models showing what the temperature would be under various conditions. The models take into account the known properties of the system, including the temperature of the star and the planet’s orbital distance. The temperature of the dayside of Mercury is also shown for reference.
The dayside brightness of TRAPPIST-1 b at 15 microns corresponds to a temperature of about 500 kelvins (roughly 450 degrees Fahrenheit). This is consistent with the temperature assuming the planet is tidally locked (one side facing the star at all times), with a dark-colored surface, no atmosphere, and no redistribution of heat from the dayside to the nightside.
If the heat energy from the star were distributed evenly around the planet (for example, by a circulating carbon dioxide-free atmosphere), the temperature at 15 microns would be 400 kelvins (260 degrees Fahrenheit). If the atmosphere had a substantial amount of carbon dioxide, it would emit even less 15-micron light and would appear to be even cooler.
Although TRAPPIST-1 b is hot by Earth standards, it is cooler than the dayside of Mercury, which consists of bare rock and no significant atmosphere. Mercury receives about 1.6 times more energy from the Sun than TRAPPIST-1 b does from its star.
Credits
Illustration
NASA, ESA, CSA, Joseph Olmsted (STScI)
Science
Thomas P. Greene (NASA Ames), Taylor Bell (BAERI), Elsa Ducrot (CEA), Pierre-Olivier Lagage (CEA)
| About The Object | |
|---|---|
| Object Name | TRAPPIST-1 b |
| Object Description | Rocky Exoplanet |
| R.A. Position | 23h 06m 30s |
| Dec. Position | -05d 02m 30s |
| Constellation | Aquarius |
| Distance | 40 light-years |
| Dimensions | Diameter: 1.1 × Earth; Mass: 1.4 × Earth |
| About The Data | |
| Data Description | time-series photometry of secondary eclipse |
| Instrument | MIRI |
| Exposure Dates | 2022: November 8, 12, 20, 24, and December 3 |
| Filters | F1500W |
| About The Object | |
|---|---|
| Object Name | A name or catalog number that astronomers use to identify an astronomical object. |
| Object Description | The type of astronomical object. |
| R.A. Position | Right ascension – analogous to longitude – is one component of an object's position. |
| Dec. Position | Declination – analogous to latitude – is one component of an object's position. |
| Constellation | One of 88 recognized regions of the celestial sphere in which the object appears. |
| Distance | The physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs. |
| Dimensions | The physical size of the object or the apparent angle it subtends on the sky. |
| About The Data | |
| Data Description |
|
| Instrument | The science instrument used to produce the data. |
| Exposure Dates | The date(s) that the telescope made its observations and the total exposure time. |
| Filters | The camera filters that were used in the science observations. |
| About The Image | |
| Image Credit | The primary individuals and institutions responsible for the content. |
| Publication Date | The date and time the release content became public. |
| Color Info | A brief description of the methods used to convert telescope data into the color image being presented. |
| Orientation | The rotation of the image on the sky with respect to the north pole of the celestial sphere. |
