Absolute Beginner
Scientists found a planet near a star called GJ 887. The star is only 10.7 light-years away from Earth.
A light-year is the distance light travels in one year. It is a very long way.
The planet, called GJ 887 d, is in the habitable zone of its star. This means it could have liquid water.
Scientists want to look at this planet with a powerful telescope called the James Webb Space Telescope.
- planet
- a large round object in space that moves around a star
- star
- a ball of hot gas in space that makes its own light
- distance
- how far away something is
- light-year
- the distance that light travels in one year
- habitable
- able to support living things
- zone
- a specific area or region
- liquid
- a substance that flows, like water
- telescope
- a tool used to see objects that are very far away
Elementary
Astronomers have confirmed GJ 887 d as a super-Earth orbiting in the habitable zone of its star, GJ 887, which is just 10.7 light-years away from our solar system.
The discovery was published in the journal Astronomy and Astrophysics. A super-Earth is a planet larger than Earth but smaller than Neptune.
GJ 887 d has a mass about 6.1 times that of Earth and takes 51 days to orbit its star. Its star, GJ 887, is a red dwarf, a type of small and cool star that lives for a very long time.
Because GJ 887 d is so close to Earth in cosmic terms, scientists believe the James Webb Space Telescope could study its atmosphere and look for signs of life.
- astronomers
- scientists who study stars, planets, and space
- confirmed
- proved to be true after careful testing
- super-Earth
- a planet larger than Earth but smaller than Neptune
- habitable zone
- the area around a star where liquid water could exist on a planet's surface
- mass
- the amount of matter in an object
- orbit
- to travel in a curved path around something
- red dwarf
- a small, cool type of star that burns slowly for billions of years
- atmosphere
- the layer of gases surrounding a planet
Intermediate
A team of astronomers has confirmed GJ 887 d, a super-Earth with 6.1 times the mass of our planet, as a resident of the habitable zone of the red dwarf star GJ 887, located just 10.7 light-years from the Sun. The discovery was published in the journal Astronomy and Astrophysics.
GJ 887 d is only the second known potentially habitable exoplanet within 11 light-years of Earth, after Proxima Centauri b. Its 51-day orbital period places it comfortably within the habitable zone of its host star, where temperatures could in principle sustain liquid water on a planetary surface.
Red dwarf stars like GJ 887 have attracted considerable scientific interest as hosts of potentially habitable worlds. They are the most common type of star in the Milky Way, and their long lifespans give life more time to emerge. However, they also produce intense flaring activity that could strip a planet of its atmosphere.
The proximity of GJ 887 makes this discovery particularly exciting: GJ 887 d is now considered a prime target for atmospheric characterisation by the James Webb Space Telescope, which could search the planet's spectrum for biosignatures such as oxygen, methane, or water vapour.
- exoplanet
- a planet that orbits a star outside our solar system
- orbital period
- the time a planet takes to complete one full orbit around its star
- host star
- the star that a planet orbits
- flaring
- producing sudden bursts of intense radiation
- proximity
- closeness in distance
- characterisation
- the process of determining the nature and properties of something
- biosignatures
- chemical or physical signs that indicate the presence of life
- spectrum
- the range of wavelengths of light from a source, used to identify its chemical composition
Advanced
The confirmation of GJ 887 d as a habitable-zone super-Earth at a distance of just 10.7 light-years from the Sun represents a rare convergence of proximity and promise in the search for potentially life-bearing worlds beyond our solar system. Published in Astronomy and Astrophysics, the study elevates GJ 887 d to the short list of exoplanets tractable for near-term atmospheric characterisation.
With a minimum mass of 6.1 Earth masses and an orbital period of 51 days, GJ 887 d sits at the inner edge of the conservative habitable zone of its M-dwarf host, where stellar insolation models suggest the possibility of maintaining liquid water under a range of atmospheric compositions. Its status as the second confirmed potentially habitable exoplanet within 11 light-years, after Proxima Centauri b, underscores the growing realisation that temperate rocky worlds are not rare outliers but common products of planetary formation around the most abundant stellar type in the galaxy.
M-dwarf habitability, however, remains contested. GJ 887 is an unusually photometrically quiet red dwarf, exhibiting markedly lower ultraviolet and X-ray flare activity than most of its stellar class. This quiescence makes it a more hospitable environment for sustained atmospheric retention, distinguishing GJ 887 d from the more flare-battered Proxima Centauri b and lending weight to the optimistic interpretation of its habitability.
The James Webb Space Telescope represents the instrument best positioned to pursue atmospheric reconnaissance of GJ 887 d. Transmission spectroscopy during transit events could reveal molecular absorption features attributable to water vapour, carbon dioxide, ozone, or methane, the latter two being potential biosignatures if found in disequilibrium concentrations. Given JWST's finite operational horizon, prioritisation of GJ 887 d in the observation queue will likely require a community consensus that its atmospheric probability justifies the telescope time investment.
- convergence
- the coming together of two or more things at a single point
- tractable
- capable of being dealt with or studied successfully
- insolation
- the amount of solar radiation received by a surface
- photometrically quiet
- describing a star that produces very little variation in brightness or flare activity
- quiescence
- a state of being quiet or inactive
- transmission spectroscopy
- a technique for studying a planet's atmosphere by analysing starlight filtered through it during a transit
- disequilibrium
- a state in which a system is not in chemical balance, often indicating ongoing processes
- reconnaissance
- a preliminary survey to gather information about an unknown environment
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