2 potentially habitable 'Super-Earths' and a record-setting 'Cold Neptune' found in exoplanet haul

Sam

Jan 5, 2020
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Great. This method does find Earth planets farther out from the star than does the transit method..
 

rod

Oct 22, 2019
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Astronomers have found two more potentially life-supporting alien planets in our neck of the cosmic woods, as well as a weird and record-setting 'cold Neptune.'

2 potentially habitable 'Super-Earths' and a record-setting 'Cold Neptune' found in exoplanet haul : Read more
"As Feng said, GJ180 d is a super-Earth, a world slightly bigger than our own; the newfound exoplanet's mass is at least 7.5 times that of Earth, the researchers determined. GJ229A c is a super-Earth, too, harboring at least 7.9 Earth masses."
"The newly discovered "cold Neptune," GJ 433 d, doesn't seem like a good candidate for life, but it's interesting for other reasons. The planet, which is at least 4.9 times more massive than Earth, orbits a dim red dwarf just 29.5 light-years from Earth. "GJ 433 d is the nearest, widest and coldest Neptune-like planet ever detected," Feng said."

Okay, these exoplanets orbit red dwarf stars and the inclination of their orbits, important in the radial velocity method is not well determined so these are minimum masses, they could be much larger. The cold Neptune cannot be 4.9 earth masses - that would be a smaller super-earth than the other two, GJ180 and GJ 229A. Some more research will be underway concerning these exoplanets. The super-earths near 7.5 and 7.9 earth masses could also be 2 earth radii in size or larger. In our solar system, planets like this do not exist. GJ 433 d orbital period is 36 days, the others 106 and 122 days and closer to their parent stars than Mercury is to our Sun. https://phys.org/news/2020-01-cold-neptune-temperate-super-earths-orbiting.html

The Extrasolar Planets Encyclopaedia
 
Jan 14, 2020
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Great. This method does find Earth planets farther out from the star than does the transit method.
True, as long as the star is small and the planet is big. This method won't work well for stars of both about 1 solar mass (our own) and planets of 1 earth mass unless sensitivity of wobble detection can be improved enormously. I am not sure where we are at now though.

The degree of a star's wobble depends on the relative masses of the two objects and the separation distance. So what would calculations show about our earth? By which I mean with present techniques, could the wobble of our sun be detected due to the gravitational attraction of the orbital rotation of 1 earth mass at 1 AU distance and viewed from, say, a distance of 10 light years? If not, we will never find a habitable planet by our standards let alone interesting alien life.

And even if such a planet were found, it proves nothing about life. Our science cannot get us or our instruments to even the nearest planet in a human life span. Discouraging.
 
Jan 15, 2020
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Astronomers have found two more potentially life-supporting alien planets in our neck of the cosmic woods, as well as a weird and record-setting 'cold Neptune.'

2 potentially habitable 'Super-Earths' and a record-setting 'Cold Neptune' found in exoplanet haul : Read more
4 light yrs are around 9,500 billion kms and today our spaceships manage like 100,000 kms/day. Only 1 billion kms could be reached in around 10,000 days (27 yrs). What we the humans could gain knowing the closest exoplanet is at 4 light years away?
 

rod

Oct 22, 2019
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FYI, New Horizons traveled about 16 km/s. Moving at this velocity at a constant rate, it will take nearly 75,000 years to travel 4 light-years distance. Traveling similar to some meteor shower velocities observed on Earth - 35 km/s, 34285 years.
 
Jan 16, 2020
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I'm puzzled why the LARGER planets are called "super-earths" and the SMALLER planet is called a "cold Neptune". If the smaller planet is only 5-6 times the size of Earth it is not like Neptune, which is 17 times larger than Earth. Also, the "super-Earth" sizes at 7x are quite a bit larger than anything likely to be actually Earthlike.
 
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rod

Oct 22, 2019
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I commented earlier, the report said about the cold Neptune, "The newly discovered "cold Neptune," GJ 433 d, doesn't seem like a good candidate for life, but it's interesting for other reasons. The planet, which is at least 4.9 times more massive than Earth"

Here is a report on GJ 433 d using the exoplanet list, http://exoplanet.eu/catalog/gj_433_d/ The mass is "Mass*sin(I)" and is 4.94 Jupiter masses, not earth masses. The mass upper limit is provided because the lower limit is not well measured. I ran a MS SQL query against the database for exoplanet masses in the range 1.5 to 10 earth masses. There are 169 listed in a database of 4168, confirmed exoplanets now. Our solar system has no such planets like this, same for hot jupiters and other exoplanet varieties reported now.
 
Jan 16, 2020
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I commented earlier, the report said about the cold Neptune, "The newly discovered "cold Neptune," GJ 433 d, doesn't seem like a good candidate for life, but it's interesting for other reasons. The planet, which is at least 4.9 times more massive than Earth"

Here is a report on GJ 433 d using the exoplanet list, http://exoplanet.eu/catalog/gj_433_d/ The mass is "Mass*sin(I)" and is 4.94 Jupiter masses, not earth masses. The mass upper limit is provided because the lower limit is not well measured. I ran a MS SQL query against the database for exoplanet masses in the range 1.5 to 10 earth masses. There are 169 listed in a database of 4168, confirmed exoplanets now. Our solar system has no such planets like this, same for hot jupiters and other exoplanet varieties reported now.
Great, that explains things! However, if it is 5x the size of Jupiter, why call it a "Neptune"? Distance? In terms of composition, it must have an interior more like Jupiter than Neptune.
 
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rod

Oct 22, 2019
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Great, that explains things! However, if it is 5x the size of Jupiter, why call it a "Neptune"? Distance? In terms of composition, it must have an interior more like Jupiter than Neptune.
FYI, you have a good eye here. I think there is confusion between GJ 433 d vs. GJ 433 c, this is the cold Neptune in the research papers, Search for Nearby Earth Analogs. II. Detection of Five New Planets, Eight Planet Candidates, and Confirmation of Three Planets around Nine Nearby M Dwarfs

This report in the abstract says about GJ 433 c, "In addition, we find GJ 433 c, a cold super-Neptune belonging to an unexplored population of Neptune-like planets."

This makes more sense because Mass*sin(i) is 0.09055 MJup. Exoplanet research and studies can be fun but confusing at times too, like the different names and letters used :)---Rod
 

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