Possible water world spotted orbiting an alien star

[Admin]

A potentially habitable water-rich world just 100 light-years away from Earth could be one of the best places to search for life.

Possible water world spotted orbiting an alien star : Read more

 

[rod]

Different reports I read on TOI-1452 b suggest temperatures some 300 K to 326 K or so. It could be warmer. This site reports properties of the system. The Extrasolar Planet Encyclopaedia — TOI-1452 b (exoplanet.eu)

Ref - TOI-1452 b: SPIRou and TESS Reveal a Super-Earth in a Temperate Orbit Transiting an M4 Dwarf, https://iopscience.iop.org/article/10.3847/1538-3881/ac7cea, 12-August-2022.

"Abstract Exploring the properties of exoplanets near or inside the radius valley provides insight on the transition from the rocky super-Earths to the larger, hydrogen-rich atmosphere mini-Neptunes. Here, we report the discovery of TOI-1452b, a transiting super-Earth (Rp = 1.67 ± 0.07 R⊕) in an 11.1 day temperate orbit (Teq = 326 ± 7 K) around the primary member (H = 10.0, Teff = 3185 ± 50 K) of a nearby visual-binary M dwarf. The transits were first detected by the Transiting Exoplanet Survey Satellite, then successfully isolated between the two 3farcs2 companions with ground-based photometry from the Observatoire du Mont-Mégantic and MuSCAT3. The planetary nature of TOI-1452b was established through high-precision velocimetry with the near-infrared SPIRou spectropolarimeter as part of the ongoing SPIRou Legacy Survey. The measured planetary mass (4.8 ± 1.3 M⊕) and inferred bulk density (5.6 -1.6/+1.8 g cm^−3) is suggestive of a rocky core surrounded by a volatile-rich envelope. More quantitatively, the mass and radius of TOI-1452b, combined with the stellar abundance of refractory elements (Fe, Mg, and Si) measured by SPIRou, is consistent with a core-mass fraction of 18% ± 6% and a water-mass fraction of 22 -13/+21 %. The water world candidate TOI-1452b is a prime target for future atmospheric characterization with JWST, featuring a transmission spectroscopy metric similar to other well-known temperate small planets such as LHS 1140b and K2-18 b. The system is located near Webb's northern continuous viewing zone, implying that is can be followed at almost any moment of the year."

[My observation. http://exoplanet.eu/catalog/toi-1452_b/ shows properties. No disc is detected. I calculate P = 1.1028E+01 days, P listed = 11.06201 days. In 1 Gyr the exoplanet could complete 3.3121E+10 revolutions if stable orbit. The paper shows 11.1 day period. The calculated temperature is 300 K. Follow up observations are needed to verify this water world candidate.]

 

[Helio]

Different reports I read on TOI-1452 b suggest temperatures some 300 K to 326 K or so. It could be warmer. This site reports properties of the system. The Extrasolar Planet Encyclopaedia — TOI-1452 b (exoplanet.eu)

I see Exoplanet.eu just added it. [I spent an hour writing a program to add newbie exoplanet data to my program. Oh well, glad they are quicker than I thought. ]

Based on the star temp. (3185K) and star radius (0.275 solar rad.), the effective temp equates to ~ 298K. Thus, the inner HZ will be outside this orbit (270K is the upper limit). But, if the Bond Albedo is increased to just over 0.5, then it does fit. I assume a water world might have a higher albedo. But is this their reasoning?

[My observation. http://exoplanet.eu/catalog/toi-1452_b/ shows properties. No disc is detected. I calculate P = 1.1028E+01 days, P listed = 11.06201 days.

That's a striking difference! How did you get that value?

 

[rod]

I see Exoplanet.eu just added it. [I spent an hour writing a program to add newbie exoplanet data to my program. Oh well, glad they are quicker than I thought. ]

Based on the star temp. (3185K) and star radius (0.275 solar rad.), the effective temp equates to ~ 298K. Thus, the inner HZ will be outside this orbit (270K is the upper limit). But, if the Bond Albedo is increased to just over 0.5, then it does fit. I assume a water world might have a higher albedo. But is this their reasoning?


That's a striking difference! How did you get that value?

Helio, 1.1028E+01 days, P listed = 11.06201 days. 1.1028E+01 = 11.028-day period compared to the exoplanet.eu site showing 11.06201 day period. Other reports suggest ~ 11.1 day period. I use my own astronomy spreadsheet using Kepler laws and Jean Meeus algorithms.

Ref - TOI-1452 b: SPIRou and TESS Reveal a Super-Earth in a Temperate Orbit Transiting an M4 Dwarf, https://iopscience.iop.org/article/10.3847/1538-3881/ac7cea, 12-August-2022. "Abstract Exploring the properties of exoplanets near or inside the radius valley provides insight on the transition from the rocky super-Earths to the larger, hydrogen-rich atmosphere mini-Neptunes. Here, we report the discovery of TOI-1452b, a transiting super-Earth (Rp = 1.67 ± 0.07 R⊕) in an 11.1 day temperate orbit (Teq = 326 ± 7 K) around the primary member (H = 10.0, Teff = 3185 ± 50 K) of a nearby visual-binary M dwarf...."

Note the reference paper, 11.1 day period with temperature 326 K. I think more caution is needed here. This is an example from JWST where CO2 is detected unambiguously for the first time in an exoplanet atmosphere.

Webb telescope makes first unequivocal detection of carbon dioxide in an exoplanet atmosphere

For the first time, astronomers have found unambiguous evidence of carbon dioxide in the atmosphere of an exoplanet (a planet outside our solar system).

phys.org

This claim of a water world needs solid verification. At the moment, I do not think folks know if it has land masses or land mass and an atmosphere, along with what type of atmosphere and composition and density. Another note, so far with more than 5100 exoplanets documented, none are known for certain to contain life on them.

 

[Helio]

You should revisit that algorithm. Using the Kepler model...

T^2 = a^3 / [G(M+m)/(4*pi^2)]
M+m is close enough to just using M since the planet mass is insignificant.

a = 0.061 AU
M = 0.249 solar masses
...T ~ 11 days

 

[Helio]

This claim of a water world needs solid verification. At the moment, I do not think folks know if it has land masses or land mass and an atmosphere, along with what type of atmosphere and composition and density. Another note, so far with more than 5100 exoplanets documented, none are known for certain to contain life on them.

Right, but no one, IMO, would guess that we would have the capability at this point of determining life on planets so many trillions of miles from here. Yet, they are getting more and more capable.

 

[rod]

You should revisit that algorithm. Using the Kepler model...

T^2 = a^3 / [G(M+m)/(4*pi^2)]
M+m is close enough to just using M since the planet mass is insignificant.

a = 0.061 AU
M = 0.249 solar masses
...T ~ 11 days

Helio, the algorithm computes the area of the ellipse using semi-minor and semi-major axis and the perimeter length along with velocities in the orbit I will stay my course here and compare to published values. However, your approach is useful and easier.

 

[rod]

Right, but no one, IMO, would guess that we would have the capability at this point of determining life on planets so many trillions of miles from here. Yet, they are getting more and more capable.

Helio, without verification of a definite water world, in my view we have hype for science reporting to the public and likely to promote the belief that there is life on other worlds. In our own solar system, we know for certain life is here on Earth.

 

[Unclear Engineer]

I would expect such a world to b tidally locked to its star, assuming lots of liquid to create drag on rotation and such close orbit.

Any insights on how a tidally locked planet with water would behave at this estimated average temperature? I am guessing that it would make a big difference whether the "ocean" covers the entire surface, or is force to flow around exposed continents.

But, one way or anther, I would think there could be some places that are "just right" for life to develop, and then evolve to spread to less hospitable niches.

Just how detailed of a picture can Webb get of this planet? What can we expect a picture to be able to resolve, if we can see through the atmosphere to a surface?

 

[rod]

I would expect such a world to b tidally locked to its star, assuming lots of liquid to create drag on rotation and such close orbit.

Any insights on how a tidally locked planet with water would behave at this estimated average temperature? I am guessing that it would make a big difference whether the "ocean" covers the entire surface, or is force to flow around exposed continents.

But, one way or anther, I would think there could be some places that are "just right" for life to develop, and then evolve to spread to less hospitable niches.

Just how detailed of a picture can Webb get of this planet? What can we expect a picture to be able to resolve, if we can see through the atmosphere to a surface?

All very good questions so I will wait to see what JWST *observes* and reports for TOI-1452 b. I approach reports like this with caution and avoid hype Astrobiology as a science is yet to be confirmed like Galileo did by viewing the Galilean moons moving around Jupiter through his telescope. Even today using my telescopes I can see that those moons are still there.

 

[Helio]

Helio, the algorithm computes the area of the ellipse using semi-minor and semi-major axis and the perimeter length along with velocities in the orbit I will stay my course here and compare to published values. However, your approach is useful and easier.

Their table shows an e=0, but they state above that table an e=0.12 , with an e < 0.32 with 95% confidence.

I can't believe your algorithm would be 10x off from a Keplerian orbit that matches their value. Something must be wrong, IMO.

 

[Helio]

Helio, without verification of a definite water world, in my view we have hype for science reporting to the public and likely to promote the belief that there is life on other worlds. In our own solar system, we know for certain life is here on Earth.

Maybe, but if it were unreported then we would be saying later, if water is found as suggested, "Why didn't you tell us?"

I think any exoplanetary news that is close to a 50/50 chance of proving itself is worth presenting if it is somewhat exciting.

There are density limits for planets of a known size. The stellar temperature plays a key role as well. So it may be that water is the best explanation, but being in a dwarf binary might just limit the core density, thus limiting the chances for water, or at least massive amounts of water.

They will need to demonstrate either a high albedo or that the effective temperature equations establishing the HZ are wrong. The higher albedo seems likely for a water world, not that I'm any expert.

But direct imaging seems unlikely given how close it is to the star. Can the JWST mask to this resolution?

 

[Helio]

I would expect such a world to b tidally locked to its star, assuming lots of liquid to create drag on rotation and such close orbit.

That's a safe bet, even without water.

Any insights on how a tidally locked planet with water would behave at this estimated average temperature? I am guessing that it would make a big difference whether the "ocean" covers the entire surface, or is force to flow around exposed continents.

Given its size (R=1.67 Rearth), its atmosphere should have significant flows from the hot to cool side, causing more even temperatures than otherwise.

But, one way or anther, I would think there could be some places that are "just right" for life to develop, and then evolve to spread to less hospitable niches.

Yes. I've seen, casually, some reports on this. Even more extreme temperatures (less atmospheres) can, in some cases, have moderate temperatures at the terminator, IIRC.

 

[billslugg]

Wherever there is water there are fish.
Wherever there are fish there are fisherpersons.
I rest my case.

 

[rod]

Wherever there is water there are fish.
Wherever there are fish there are fisherpersons.
I rest my case.

This is great

 

[Helio]

Sounds a bit fishy to me.