Finally, a planet around Barnard’s Star!

[ProtoJeb21]

A likely planet candidate has been found orbiting the nearby red dwarf Barnard’s Star using over 20 years worth of data from nearly every major exoplanet hunting spectrograph. This planet, Barnard b, is an extremely rare Super-Earth at the system’s frost line, where water in the protoplanetary disk turns from a gas to a solid. It’s about 3.2 times the mass of Earth and takes over 200 days to complete a single orbit. While radial velocity data isn’t expected to confirm this candidate — the discovery team basically used all that they could possibly use — Barnard b appears to be a promising target for direct imaging in the mid-2020’s. 

https://amp.space.com/42423-barnards-star-super-earth-exoplanet-discovery.html

[Scotius]

It's so close! And it's getting closer with every second Maybe it's time to take another look at Project Daedalus?

[ProtoJeb21]

43 minutes ago, Scotius said:

It's so close! And it's getting closer with every second Maybe it's time to take another look at Project Daedalus?

I read about that project when I was a little kid and thought it actually launched, so for years I was waiting for it to arrive at Barnard’s Star. 

Eventually I found out it was nothing more than a proposed spacecraft that never say the light of day. Bummer. 

I think the potential for this to be directly imaged makes up for the fact that we likely aren’t visiting the system anytime in the next half a century. Not only could the surface be resolved in pre-New Horizons Pluto quality, but looking for little blobs in or around the disk of Barnard b could reveal orbiting moons. It’s certainly massive and far enough from the star to host at least one. 

[Ozymandias_the_Goat]

16 hours ago, ProtoJeb21 said:

I read about that project when I was a little kid and thought it actually launched, so for years I was waiting for it to arrive at Barnard’s Star. 

Eventually I found out it was nothing more than a proposed spacecraft that never say the light of day. Bummer. 

I suppose that that equates the disappointment that most kids would feel once you discover that Santa is naught but an elaborate ruse.

Nevertheless, it is an excellent candidate for direct imaging. A question about the nomenclature of this planet; is it correct to call it a “super earth?” Although it is a large, rocky planet with an atmosphere, I was under the impression that a super-earth also needs to be at least marginally habitable.

[ProtoJeb21]

2 hours ago, LetsGoToMars! said:

A question about the nomenclature of this planet; is it correct to call it a “super earth?” Although it is a large, rocky planet with an atmosphere, I was under the impression that a super-earth also needs to be at least marginally habitable.

The phase “Super-Earth” is usually used for any planet between the size of Earth and Neptune, either if they’re entirely rocky or have some amount of volatiles. I like to use it for planets between about 1.2 and 1.75-2.00 Earth radii, or 2-10 Earth masses, unless the planet is revealed to be volatile rich (Kepler-138d is a good example). Most Super-Earths are not in any way friendly for life, although in the case of Barnard b, it could have a subsurface ocean like Europa or Enceladus due to its likelihood of being more geologically active. 

[Green Baron]

ESO blog post on the matter. I haven't read it (not the time), maybe it is interesting for you guys:

https://www.eso.org/public/blog/searching-for-an-exoplanet/

One figure met my eye: 4.3km/h. Apparently the observed speed change. Doh.

Edited November 15, 2018 by Green Baron

[Adstri]

It's interesting how we are discovering planets around the stars nearer to us later than expected.

I suppose that it mostly has to due with the size of these planets and the stars as well.

[Ozymandias_the_Goat]

14 hours ago, Adstriduum said:

It's interesting how we are discovering planets around the stars nearer to us later than expected.

I suppose that it mostly has to due with the size of these planets and the stars as well.

Yes, this is primarily due to the size of the planet. It was discovered using the Doppler method, a technique which usually works for large planets, but cannot truly detect smaller planets. However, since Barnards star is so close to the earth, it was easier to detect the minuscule effect the orbiting planet has on its sun. It also probably helps that Barnards star is so low mass, because that will amplify the effect of the gravitational pull from the planet. If this star system were further away from earth, or the planet was smaller and the star larger, it is likely that we would have never discovered the planet.

Of course, it took decades of collected data to prove with reasonable accuracy that this is truly a planet. There is still a small possibility that this is a glitch, but probably there is a 100% certified real planet here. 

[Spaceception]

I wonder what the likelihood of other planets is. Also, why does it seem so many systems only have 1 (Or at least very few) planet(s)? I've never seen any reasons put forth. I know Proxima might have another one, but what about Ross 128? And this system?

Edited November 28, 2018 by Spaceception

[Ozymandias_the_Goat]

11 minutes ago, Spaceception said:

I wonder what the likelihood of other planets is. Also, why does it seem so many systems only have 1 (Or at least very few) planet(s)? I've never seen any reasons put forth. I know Proxima might have another one, but what about Ross 128? And this system?

I suppose most systems have few planets because their protstellar nebulae were generally small, reflected in the small size of the star itself, and thus there simply was not enough material close enough to form many planets (?). Because the sun is a relatively large star, perhaps there was s just more dust orbiting it, and there was simply a greater probability of more planets forming.

It is also probable that the other systems mentioned have planets, but they are either too small to be detected through the Doppler method, or not properly lined up for the transit method.

Breakthrough starshot, anyone?

Edited November 28, 2018 by Ozymandias_the_Goat