B Barnard's Star, 6 Light-Years Away, May Have Cold SuperEarth

[CygnusX-1]

The planet:

Distance from star: 0.4 AU (comparable to Mercury)
Orbital period: 233 days (comparable to Venus)
Mass: at least 3 Earth masses
Temperature: -270 F (comparable to Saturn)

Barnard's Star:

Distance from us: 6 light-years; second closest star system to Sun after Alpha Centauri
Spectral type: M3.5 V (red dwarf)
Mass: 0.16 Suns
Diameter: 0.18 Suns
Luminosity: 0.0033 Suns
Temperature: 3280 K
Rotation period: 140 days

Link: Nature

https://www.skyandtelescope.com/astronomy-news/a-chilly-super-earth-may-orbit-barnards-star/

 

[trurle]

Likely a sort of very small gas/ice giant with super-dense hydrogen atmosphere. It would be helium and nitrogen enriched due hydrogen loss to space during last 10 billion years, but i doubt the atmosphere pressure can be below Venusian level (90 bar)

 

[chasrob]

Back in the 1960s-70s, didn't an astronomer claim to have detected a planet around Barnard's star; but later, others insisted it was a false detection?

 

[phyzguy]

Back in the 1960s-70s, didn't an astronomer claim to have detected a planet around Barnard's star; but later, others insisted it was a false detection?

Yes, that detection was proven false. But they think they have it right this time. Time will tell.

 

[CygnusX-1]

Back in the 1960s-70s, didn't an astronomer claim to have detected a planet around Barnard's star; but later, others insisted it was a false detection?

Yes, that was Peter van de Kamp, who claimed Barnard's Star had two giant planets akin to Jupiter and Saturn.

Astronomers George Gatewood and Heinrich Eichhorn later cast doubt on those planets. The story appears in chapter 5 of Ken Croswell's book Planet Quest. The full account is much too long to quote here, but here's one especially entertaining paragraph:

Eichhorn thought the project a bad idea. Said Eichhorn, "I asked him, `Who was the second person who flew solo across the Atlantic?' He said he didn't know. And I told him he'd be as well remembered as that person." That's because Eichhorn was certain that Gatewood would simply repeat van de Kamp's work. "I fully expected the planets to be confirmed," said Eichhorn. "I hadn't the slightest doubt. Look at van de Kamp's original papers: they're perfectly convincing that the effect is there."

---from Planet Quest by Ken Croswell, page 95.

The new discovery may or may not hold up. Time will tell.

 

[trurle]

The new discovery may or may not hold up. Time will tell.

The Barnard`s star radial velocity signal is very noisy due star activity typical for small red dwarfs - what`s why the discovery was late despite proximity of the star itself and vast amount of resources used for discovery. The current candidate planet confidence is about 99% though, and it will either vanish or reach 99.9% in 3-4 years.

 

[bob012345]

Yes, that detection was proven false. But they think they have it right this time. Time will tell.

Is it possible that the "proven false" part may have been wrong?

 

[stefan r]

Is it possible that the "proven false" part may have been wrong?

The prediction is that a cyclic pattern will be there. If it is periodically not there then it was wrong.

 

[bob012345]

The prediction is that a cyclic pattern will be there. If it is periodically not there then it was wrong.

What's false, that there is no planets or just that there is no confidence van de Kamp detected them?