NASA exoplanet telescope discovers 'super-Earth' in its star's Goldilocks zone

a brownish planet in space, with a fiery red star in the background
An illustration shows a super-Earth exoplanet orbiting a red dwarf star. (Image credit: Robert Lea created with Canva)

NASA's Transiting Exoplanet Survey Satellite (TESS) has spotted a 'super-Earth' planet orbiting in the habitable zone of a relatively nearby red dwarf star. The extrasolar planet or 'exoplanet,' which has been designated TOI-715 b, might have company in the form of an Earth-sized planet. 

The discovery is significant because red dwarfs, which are smaller and cooler than the sun, are often suggested to be the stars most likely to host small rocky habitable planets.

According to a NASA statement, TOI-715 b has a width around 1.5 times that of Earth and is in the region around its star where liquid water would be able to survive without boiling or freezing, called the habitable zone because of the importance of liquid water to life. Scientists also refer to this as the 'Goldilocks zone,' because it is neither 'too hot' nor 'too cold' to support liquid water. 

Using TESS, an international team of scientists led by University of Birmingham scientist Georgina Dransfield spotted the super-Earth as it crossed the face of its parent red dwarf star TOI-715, located around 137 light-years from Earth, during its 19 Earth-day orbit.

Related: 2 'super-Earth' exoplanets spotted in habitable zone of nearby star

TESS has been using the tiny dips in light planets cause as they move across the face of their parent stars to find exoplanets since it launched in 2018. The so-called transit method employed by TESS is more effective when planets are close to their stars and have shorter orbits, meaning they transit the face of that star more often during an observing period. 

The relative proximity of TOI-715 b to Earth and the fact that it exists in a habitable zone close to its cool star makes this newly discovered super-Earth a prime target for further investigation with the James Webb Space Telescope (JWST).

A planet existing in the habitable zone around its star doesn't immediately mean it is habitable. For instance, a distance observer who could view the sun and its planets would see Venus, Earth, and Mars are in the habitable zone, but from our vantage point inside the solar system, we know only one is currently habitable. 

Using the JWST, astronomers could reveal characteristics about TOI-715 b that are important to habitability, such as how massive the planet is and if it still possesses an atmosphere. Researchers could then work out if the planet is a 'water world,' offering further clues to its potential habitability. 

Besides this fascinating super-Earth, scientists will now attempt to confirm the existence of its smaller Earth-sized sibling, which would likely be named TOI-715 c.

If this planet is confirmed, it will be the smallest world ever detected by TESS.

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

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Robert Lea
Contributing Writer

Robert Lea is a science journalist in the U.K. whose articles have been published in Physics World, New Scientist, Astronomy Magazine, All About Space, Newsweek and ZME Science. He also writes about science communication for Elsevier and the European Journal of Physics. Rob holds a bachelor of science degree in physics and astronomy from the U.K.’s Open University. Follow him on Twitter @sciencef1rst.

  • Big Joe
    I am disappointed I have not received any significant comments on my theory for How the Universe Works. You seem to be the only one who routinely posts or reads articles on the Cosmology Form?? Is there a better place I can post the theory to get some meaningful responses? Thanks for your earlier response. I still haven't figured out how to post a jpg figure on the site. My illustration that shows the interrelationships between the various components such as Dark & Light Matter and Dark & Light Energy is helpful in understanding the key elements of the theory. It should also be noted that it assumes that Total Matter and Total Energy in the universe are constant over time and have always existed. That is why there is no" before" and no "after" in the cyclical process. It assumes that Nature has always existed .
    Reply
  • rod
    TOI-715 b, some properties can be viewed at these sites.

    https://exoplanet.eu/catalog/toi_715_b--8668/
    https://exoplanetarchive.ipac.caltech.edu/overview/TOI-715%20b#planet_TOI-715-b_collapsible
    Reference paper cited, Ref - A 1.55 R⊕ habitable-zone planet hosted by TOI-715, an M4 star near the ecliptic South Pole, https://academic.oup.com/mnras/article/527/1/35/7172075?login=false, 18-May-2023.

    My note. 1.55 earth radii, if the mass is 3 earths, mean density about 4.43 g cm^-3. Mass is not published at this time. I plan to monitor reports on TOI-715 b and see if it is truly a habitable exoplanet. K2-18 b underwent plenty of recent revisions in the reports. Are we getting science or astrobiology hype?
    Reply
  • Atlan0001
    Just fooling around herein. More or less tangentially, I assume it is possible for more or less hollow balls to exist in the universe with the major of gravity tied only to the material shell structure and being an Earth-like planet existing three times the total surface area of the Earth with the same outer surface gravity as the smaller more materially compacted Earth. A planet, rather than star, built around a pale-ghost of a black hole, of course ('black hole lite', very lite, even solidly antigravitational interiorly from center to event horizon, so to speak).
    Reply
  • CustardSpace
    I doubt we will ever venture that far in my lifetime, but it's reassuring to know that sometime in the future we could have a plan B.
    Reply
  • Big Joe
    Admin said:
    NASA's exoplanet-hunting spacecraft TESS has spotted a 'super-Earth' in the habitable zone of its red dwarf star, with indications it may have Earth-sized company.

    NASA exoplanet telescope discovers 'super-Earth' in its star's Goldilocks zone : Read more
    I find it hard to understand all of the fuss over a super-earth or exoplanets in general when there is much to learn about black holes, dark matter, dark energy, and how science works. I doubt they will shed new light on the pressing issues in astronomy. At least research on our planets is moving science forward and could shed some light on potential for life beyond earth. Understanding how galaxies, stars, solar systems and planets work moves science forward. Building better sensors to look further back in time has produced some revolutionary new ideas and insights. However, discovery of life or conditions suitable for life in other solar systems or galaxies is as worthwhile as the SETI project has proven to be. During my year a JPL I was amazed at the effort and money spent on this program which has little hope of getting any meaningful results even if they were to detect some coherent signals.
    Reply
  • CustardSpace
    Atlan0001 said:
    Just fooling around herein. More or less tangentially, I assume it is possible for more or less hollow balls to exist in the universe with the major of gravity tied only to the material shell structure and being an Earth-like planet existing three times the total surface area of the Earth with the same outer surface gravity as the smaller more materially compacted Earth. A planet, rather than star, built around a pale-ghost of a black hole, of course ('black hole lite', very lite, even solidly antigravitational interiorly from center to even t horizon, so to speak).

    Big Joe said:
    I find it hard to understand all of the fuss over a super-earth or exoplanets in general when there is much to learn about black holes, dark matter, dark energy, and how science works. I doubt they will shed new light on the pressing issues in astronomy. At least research on our planets is moving science forward and could shed some light on potential for life beyond earth. Understanding how galaxies, stars, solar systems and planets work moves science forward. Building better sensors to look further back in time has produced some revolutionary new ideas and insights. However, discovery of life or conditions suitable for life in other solar systems or galaxies is as worthwhile as the SETI project has proven to be. During my year a JPL I was amazed at the effort and money spent on this program which has little hope of getting any meaningful results even if they were to detect some coherent signals.
    I have to agree. These Super-Earths, no matter how interesting they may be, are useless to spend too much time into researching. It's unlikely that they have any effect on mankind currently. I believe we should rather spend more time discover the secrets of our universe.
    Reply