Skip to main content
  1. Home
  2. Space
  3. News

Astronomers discover a super-Earth located in the habitable zone

By

Astronomers have discovered a type of exoplanet called a “super-Earth” located in the habitable zone of its small star, and it’s right in our cosmic backyard, just 137 light-years away. The planet, named TOI-715 b, is intriguing to astronomers who are increasingly interested in the possibility of habitable planets orbiting stars quite different from our sun.

Although it might seem to make sense to look for potentially habitable planets when looking for Earth-like planets orbiting sun-like stars, those aren’t the only targets that astronomers are interested in. One issue is that most discovered exoplanets are much larger than Earth, partly because it is so hard to detect smaller planets. Another issue is that the most common star in our galaxy by far is not a yellow dwarf star like our sun, but a smaller, dimmer, redder type called a red dwarf. When researchers discover rocky planets orbiting around red dwarfs, a few of which have been identified to date, that increases the pool of potentially habitable worlds that could be out there.

This illustration shows one way that planet TOI-715 b, a super-Earth in the habitable zone around its star, might appear to a nearby observer.
This illustration shows one way that planet TOI-715 b, a super-Earth in the habitable zone around its star, might appear to a nearby observer. NASA/JPL-Caltech

As red dwarf stars give off much less heat than stars like our sun, the habitable zone around them is tighter. The habitable zone refers to the distance from a star at which water could exist as a liquid on a planet’s surface — i.e. when the planet’s surface temperature is between 0 and 100 degrees Celsius. However, it takes much more than being in the habitable zone for a planet to be truly habitable. Other facts are important in determining habitability, like how much atmosphere the planet has, how much radiation it receives from its star, and whether it has a mix of oceans and land.

Recommended Videos

This particular exoplanet is located right in prime territory of its star’s habitable zone. It orbits the star in just 19 days, sitting right close to it. That helped astronomers to discover the planet because it frequently passes in front of its star as seen from Earth. That was how the NASA spacecraft Transiting Exoplanet Survey Satellite, or TESS, was able to identify it.

At around one and a half times the diameter of Earth, it is the smallest planet in the habitable zone discovered by TESS so far. To learn more about whether it is,, in fact,, habitable, astronomers need to use another tool, such as the James Webb Space Telescope, to observe its atmosphere and see if it can detect water there.

The research is published in the journal Monthly Notices of the Royal Astronomical Society.

Editors' Recommendations

Topics
Georgina Torbet
Georgina Torbet
Space Writer
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
Voyager 1 spacecraft is still alive and sending signals to Earth
NASA’s Voyager 1 spacecraft is depicted in this artist’s concept traveling through interstellar space, or the space between stars, which it entered in 2012.

NASA's two Voyager spacecraft, launched in the 1970s, have passed beyond the orbit of Pluto and into interstellar space, making them the most distant man-made objects to exist in the universe. However, as you'd expect from technology that is nearly 50 years old, the pair of probes have had their share of technical difficulties in their time. But now, NASA has announced that it is back in contact with Voyager 1, around five months after communications with the spacecraft were disrupted. The remarkable pair of explorers continue out into the depths of space to fight another day.

NASA’s Voyager 1 spacecraft is depicted in this artist’s concept traveling through interstellar space, or the space between stars, which it entered in 2012. NASA/JPL-Caltech

Read more
Biggest stellar black hole to date discovered in our galaxy
Astronomers have found the most massive stellar black hole in our galaxy, thanks to the wobbling motion it induces on a companion star. This artist’s impression shows the orbits of both the star and the black hole, dubbed Gaia BH3, around their common centre of mass. This wobbling was measured over several years with the European Space Agency’s Gaia mission. Additional data from other telescopes, including ESO’s Very Large Telescope in Chile, confirmed that the mass of this black hole is 33 times that of our Sun. The chemical composition of the companion star suggests that the black hole was formed after the collapse of a massive star with very few heavy elements, or metals, as predicted by theory.

Black holes generally come in two sizes: big and really big. As they are so dense, they are measured in terms of mass rather than size, and astronomers call these two groups of stellar mass black holes (as in, equivalent to the mass of the sun) and supermassive black holes. Why there are hardly any intermediate-mass black holes is an ongoing question in astronomy research, and the most massive stellar mass black holes known in our galaxy tend to be up to 20 times the mass of the sun. Recently, though, astronomers have discovered a much larger stellar mass black hole that weighs 33 times the mass of the sun.

Not only is this new discovery the most massive stellar black hole discovered in our galaxy to date but it is also surprisingly close to us. Located just 2,000 light-years away, it is one of the closest known black holes to Earth.

Read more
Hubble discovers over 1,000 new asteroids thanks to photobombing
This NASA/ESA Hubble Space Telescope image of the barred spiral galaxy UGC 12158 looks like someone took a white marking pen to it. In reality it is a combination of time exposures of a foreground asteroid moving through Hubble’s field of view, photobombing the observation of the galaxy. Several exposures of the galaxy were taken, which is evidenced by the dashed pattern.

The Hubble Space Telescope is most famous for taking images of far-off galaxies, but it is also useful for studying objects right here in our own solar system. Recently, researchers have gotten creative and found a way to use Hubble data to detect previously unknown asteroids that are mostly located in the main asteroid belt between Mars and Jupiter.

The researchers discovered an incredible 1,031 new asteroids, many of them small and difficult to detect with several hundred of them less than a kilometer in size. To identify the asteroids, the researchers combed through a total of 37,000 Hubble images taken over a 19-year time period, identifying the tell-tale trail of asteroids zipping past Hubble's camera.

Read more