Astronomers have announced the discovery of Proxima Centauri c, an inhospitable super-Earth just 4.3 light-years away.

Proxima Centauri c
An artist’s rendering of the Proxima Centauri system shows the newly discovered exoplanet Proxima c (on the right), which orbits its host star in about 5.2 years. The smaller Proxima b, shown on the left, was discovered in 2016. Proxima Centauri is just 4.3 light-years from Earth.
Lorenzo Santinelli

Less than four years after the discovery of a planet orbiting our closest neighboring star, Proxima Centauri, scientists think they’ve discovered a second world in the same system.

The planet, a super-Earth called Proxima Centauri c (Proxima c for short), has at least six times more mass than Earth and orbits its star every 5.2 years. The discovery appears January 15th in the open-access journal Science Advances.

The first planet to be discovered in this system, Proxima b, initially raised astronomers’ hopes: The Earth-size planet orbits Proxima Centauri every 11.2 days, putting it in the so-called habitable zone, where liquid water may exist on a rocky surface. However, further study has showed that the magnetically active star likely robbed the planet of its atmosphere long ago.

Super-Earth Proxima Centauri c

To find the new super-Earth, scientists used the HARPS spectrograph at the La Silla Observatory and the UVES spectrograph on the Very Large Telescope, both in Chile. Mario Damasso (Astrophysical Observatory of Torino, Italy) and colleagues analyzed data collected between 2000 and 2017, looking for the signature “wobble” in Proxima’s Centauri’s light spectrum that would indicate the presence of a planet, the same technique that enabled scientists to confirm the Proxima b’s presence in 2016.

“Stars like Proxima Centauri are rather restless and continuously present eruptions and spots on their surface, which make the detection of a planetary-induced oscillation very complicated,” says coauthor Fabio Del Sordo (University of Crete and Foundation for Research and Technology-Hellas in Heraklion, Greece).

Because the observations span almost two decades, the scientists have confidently ruled out those sources of noise, but they caution that follow-up observations are needed to confirm that the signal comes from a planet. “The problem with planets in distant orbits,” says Yiannis Tsapras (Astronomical Calculation Institute, Germany), “is that their orbital periods span several years to decades, which means that any observing campaigns need to be of comparable length, or even longer if the aim is to verify the signal over multiple orbits.” Tsapras was part of the team that discovered Proxima b but was not involved with the current study.

Proxima c is about 1.5 astronomical units (a.u.) away from its  star — just a little farther out than Earth is from the Sun, but about 30 times farther out than Proxima b. Because of this large distance, even if the planet were rocky, it would be too cold to host life as we know it.

Challenging Super-Earth’s Origin Story

The planet’s existence challenges theories explaining the formation of super-Earths. Scientists think that super-Earths like Proxima c should form near a snowline — the region where gaseous compounds such as water, carbon monoxide, or ammonia solidify into ices. These regions are sweetspots for super-Earth formation, yet this planet orbits much farther out than the snowlines in its system.

It’s also unlikely that the planet would have formed close to its star only to be kicked farther out, because planet searches indicate that there are no massive planets on closer orbits that could have done the kicking.

The discovery of this planet and others beyond the snowline “will not only help us test and improve theoretical models of how planetary systems grow and evolve (including our own), they also have important implications for planetary habitability,” says Tsapras.

Future observations with observatories ranging from the space-based Gaia mission to the submillimeter-wavelength ALMA dishes to other ground-based observatories will help confirm the planet’s existence and explain the planet’s formation.

Comments


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Rathgic

January 16, 2020 at 12:21 pm

It is a fraud to show an artist drawing as if it was what they "found".
What they found was some "data" that they then had a computer, programed by assumptionaon what data does and does not mean.

It just like Black Holes. They have not been found. They just made assumptons on what the data they found meant,

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TorbjornLarsson

January 16, 2020 at 7:11 pm

I was reflecting the other day how black hole opinions have moved on to dark matter/dark energy instead, but I see there are still some opinions.

Everyone knows, or quickly learn, that illustrations are for illustration purposes. There is no fraud in that, no more than in illustrating elementary particles as points instead of ripples in respective quantum field.

Here is a list of direct imaged planets, we have a few: https://en.wikipedia.org/wiki/List_of_directly_imaged_exoplanets . Resolution is still point like, but various areas (and wind systems!) can be mapped: https://exoplanets.nasa.gov/resources/49/first-map-of-an-exoplanet-atmosphere/ .

Here is an image of a black hole: https://eventhorizontelescope.org/ . It won the 2020 Breakthrough Prize in Fundamental Physics so far; everyone thought it would win the 2019 Nobel Prize in Physics but it (rightly) went to physical cosmology foundation and the solar type star exoplanet discovery instead. Maybe next year ...

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AJames

January 17, 2020 at 11:26 pm

Nihilistic negativism can only survive if no observational data exists to support the contention. Denying the interpretation of evidentiary data requires both how the data was obtained, knowledge of its accuracy, and the scientific principles behind it to come some conclusion. e.g. Is the principles of Bayesian analysis and bayesian inference that is used in science now somehow wrong? (The next step is to verify the methodology and repeat the experiment.)
What actual data do you have that supports your statements other than some personal belief it is wrong?

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AJames

January 18, 2020 at 11:39 pm

Rathgic. Umm… According to your own linked website: "...that huge fantasy size Black Holes exist that compress everything to a very small size and are so dense that gravity can not escape." But that premise is just wrong. Light is what cannot escape. Gravity is the consequence of spacetime's distortion which is created by the presence of mass. As such, it requires no escape of gravity inside the black hole itself. Furthermore, the gravity waves produced by the merging black holes does not come from inside them either, but are the consequence of 'shaking' the mesh of spacetime itself.
You also strangely say: "Not to mention, that the politically correct gravity formula .... for decrease in gravity force with distance .... is obviously wrong but the intellectual world, universally sees no reason to doubt its correctness. But then the intellectual community also thinks Isaac Newton's "Law" that for every force there is created an equal opposite force .... is also obviously wrong." and give the reasons to why this is true, because: "...orbits of large objects in space only occur between a large central force and much smaller orbiting bodies. (The assertion of "binary orbits" existing by equal masses, by the intellectual community to the contrary, not withstanding not being possible for the same reason.)"
Surely this cannot be, because the Earth orbits the Sun in the Solar System (just like this newly indicated planet orbiting Proxima Centauri) in an ellipse, as does the binary star Alpha Centauri once every 80-odd years (Approximately having similar masses.) e.g. This Wikipedia image link Alpha Centauri ABThese are indisputable observed facts not assumptions at all. (So much so, that we can predict the relative positions in their orbits, and calculate their parameters like mass.)
The sheer predictive power of both Newton's and Einstein's Theories as directly applied to astronomical phenomena makes the application of this "data" total relevant. What hasn't been found is any rational reason to discard their "correctness." Sorry.

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TorbjornLarsson

January 16, 2020 at 6:52 pm

There are system models that solve the snowline condensation problem. Here is one interesting, just published, that connects our system with other developing systems: https://www.livescience.com/great-divide-separates-solar-system.html .The motivation is that based on that pebble condensation seems to have been to slow in our system.

The new model is ad hoc (as of now), but it would turn the problem around and have the rings observed in developing systems being regions of various pressure that blocks dust migration early as well as place pebble formed planets/giant planet cores accordingly.

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