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Should Pluto and the other dwarf planets be planets if not all exoplanets clear their orbit

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#1 kingsbishop

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Posted 19 April 2024 - 12:22 AM

I am not sure if all exoplanets discovered have cleared their orbit as it doesn’t say anywhere that it is a requirement for exoplanets unless if it is and I am not aware of it but if it isn’t a requirement for exoplanets it shouldn’t be for our solar system either because we are not special we are a planet orbiting a star just like every other stellar system.

But my question is does the requirement of having to clear its orbit apply to exoplanets too?

#2 TOMDEY

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Posted 19 April 2024 - 01:49 AM

If dwarf stars should be stars, then it follows that dwarf planets should be planets.     Tom



#3 kingsbishop

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Posted 19 April 2024 - 08:08 AM

If dwarf stars should be stars, then it follows that dwarf planets should be planets. Tom

Agreed unless if they define exoplanets with the same laws of the definition of a planet in our solar system I will put Pluto and the other dwarf planets as planets the IAU doesn’t own nature and they certainly don’t own my opinions and decisions

Edited by kingsbishop, 19 April 2024 - 08:10 AM.

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#4 KBHornblower

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Posted 19 April 2024 - 09:10 AM

As was said in your previous thread, the exoplanets we can detect with today's technology are plenty massive to be gravitationally dominant planets.



#5 TOMDEY

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Posted 19 April 2024 - 09:24 AM

Agreed unless if they define exoplanets with the same laws of the definition of a planet in our solar system I will put Pluto and the other dwarf planets as planets the IAU doesn’t own nature and they certainly don’t own my opinions and decisions

Yeah, this ~Big Brother~ stuff doesn't play well with the Universe.    Tom

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#6 kingsbishop

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Posted 19 April 2024 - 09:46 AM

As was said in your previous thread, the exoplanets we can detect with today's technology are plenty massive to be gravitationally dominant planets.

and then there is the few minority that are not yet they are still classifying them as planets even if there was 1 planet out of all 5000 that doesn’t clear its orbit the rules of a planet need to all be the same if we can’t detect weather a planet has cleared its orbit don’t put it in the archive or make Pluto and the other dwarf planets planets again they shouldn’t change the law of a planet just because it’s not in our system otherwise then it can come across as cheating

#7 FirstSight

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Posted 21 April 2024 - 08:04 AM

Moderator note:

The topic of ths thread is similar enough to the long-ongoing Is Pluto a Planet? thread that it potentially risks violating the CN principle against starting a thread on the same topic as an existing ongoing thread. We are going to give y'all the initial benefit of the doubt that there are sufficiently distinct considerations with respect to exoplanets to justify its own thread, but if the discussion turns too much (in our opinion) into a re-litigation of the same ground as the existing Pluto thread, we may either lock this one or merge posts from this thread into the Pluto thread.

#8 russell23

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Posted 21 April 2024 - 08:49 AM

Here is an IAU document published on arXiv in 2022 that addresses exoplanets:

 

https://arxiv.org/abs/2203.09520

 

You can find the link to the pdf in the upper right.

 

If any of the exoplanets discovered to this point were in our Solar System they would be able to clear their orbits and they should be able to do the same in their own systems too.

 

The controversial area with regard to exoplanets is when it comes to brown dwarfs.  The competing ideas are:

 

~1.  Brown dwarfs are defined by their formation mechanism - specifically they are products of the star formation gas collapse process that did not acquire sufficient mass for sustained hydrogen fusion as originally proposed by Kumar in 1963 (who used the term "black dwarfs").

 

~2.  Brown dwarfs are defined by the deuterium burning limit - specifically brown dwarfs are bodies with mass exceeding the deuterium burning limit of 13 Jupiter masses.  In this definition approach formation mechanism is irrelevant.

 

Each approach has its advantages and disadvantages:

 

Formation mechanism:

 

Advantage: Bodies formed in proto-planetary disks (planets) have distinct formation channels (core accretion and disk instability) from star-like formation and this could impact the composition and dynamics of the body.  Hence, being able to identify a body by its formation process would allow for better samples for comparing against the predictions of planet and brown dwarf formation models.

 

Disadvantages:  Identifying the formation mechanism of any individual object is not an easy task.  Do we know enough about formation models at this time to really define Brown dwarfs and Gas Giants this way?  That is the question. 

 

In addition, does it make a difference whether bodies exceeding ~ 4 Jupiter masses formed via core accretion or star-like gas collapse?  Possibly the core that started the formation of the body becomes completely dissolved into the upper layers in bodies that massive.  It is already known that the Gas Giants and Ice Giants in our Solar System have "fuzzy cores" meaning there is mixing of the initial rock-ice core upward.  Perhaps that process becomes even more extreme to the point where formation mechanism is irrelevant in super-Jupiter mass gas giants?

 

 

Deuterium burning limit

 

Advantage:  It is easy to apply in practice:  Above 13 Jupiter masses you have a brown dwarf and below 13 Jupiter masses you have a gas giant. 

 

 

Disadvantages:

 

~The Deuterium burning limit is not actually a fixed 13 Jupiter masses.  The lower limit can range from 11-16 Jupiter masses.  So defining it at 13 Jupiter masses will potentially include bodies that aren't DB and exclude bodies that are DB.

 

~It is know from studies of star formation regions that the gas-collapse star formation process can form bodies with masses as small as about 4 Jupiter masses.  So the deuterium burning limit does not uniquely identify the lower mass limit of the star formation process.

 

~From modeling it is also believed that in some cases it is possible for proto-planetary disk formation processes to lead to gas giants exceeding the deuterium burning limit - possibly up to ~25 Jupiter masses.

 

The two disadvantages above combine to result in a situation where there is a mass overlap range based upon formation mechanism.

 

My opinion is that conceptually it makes more sense to define Brown Dwarfs by formation mechanism.  That would allow comparative studies between Brown Dwarfs and Gas Giant planets to see how much difference formation mechanism actually makes in the resulting structure and properties.  However, the formation mechanism definition may not be practical at this time because determination of formation mechanism is difficult and formation mechanism studies are always evolving.

 

So I think the IAU's choice of 13 Jupiter masses is a practical solution at this time.  But researchers probably should consider all bodies from 4 - 25 Jupiter masses as relevant to studies on formation and other aspects of Brown Dwarfs and Gas Giant Planets.


Edited by russell23, 21 April 2024 - 08:56 AM.


#9 kingsbishop

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Posted 21 April 2024 - 09:29 AM

Here is an IAU document published on arXiv in 2022 that addresses exoplanets:

https://arxiv.org/abs/2203.09520

You can find the link to the pdf in the upper right.

If any of the exoplanets discovered to this point were in our Solar System they would be able to clear their orbits and they should be able to do the same in their own systems too.

The controversial area with regard to exoplanets is when it comes to brown dwarfs. The competing ideas are:

~1. Brown dwarfs are defined by their formation mechanism - specifically they are products of the star formation gas collapse process that did not acquire sufficient mass for sustained hydrogen fusion as originally proposed by Kumar in 1963 (who used the term "black dwarfs").

~2. Brown dwarfs are defined by the deuterium burning limit - specifically brown dwarfs are bodies with mass exceeding the deuterium burning limit of 13 Jupiter masses. In this definition approach formation mechanism is irrelevant.

Each approach has its advantages and disadvantages:

Formation mechanism:

Advantage: Bodies formed in proto-planetary disks (planets) have distinct formation channels (core accretion and disk instability) from star-like formation and this could impact the composition and dynamics of the body. Hence, being able to identify a body by its formation process would allow for better samples for comparing against the predictions of planet and brown dwarf formation models.

Disadvantages: Identifying the formation mechanism of any individual object is not an easy task. Do we know enough about formation models at this time to really define Brown dwarfs and Gas Giants this way? That is the question.

In addition, does it make a difference whether bodies exceeding ~ 4 Jupiter masses formed via core accretion or star-like gas collapse? Possibly the core that started the formation of the body becomes completely dissolved into the upper layers in bodies that massive. It is already known that the Gas Giants and Ice Giants in our Solar System have "fuzzy cores" meaning there is mixing of the initial rock-ice core upward. Perhaps that process becomes even more extreme to the point where formation mechanism is irrelevant in super-Jupiter mass gas giants?


Deuterium burning limit

Advantage: It is easy to apply in practice: Above 13 Jupiter masses you have a brown dwarf and below 13 Jupiter masses you have a gas giant.


Disadvantages:

~The Deuterium burning limit is not actually a fixed 13 Jupiter masses. The lower limit can range from 11-16 Jupiter masses. So defining it at 13 Jupiter masses will potentially include bodies that aren't DB and exclude bodies that are DB.

~It is know from studies of star formation regions that the gas-collapse star formation process can form bodies with masses as small as about 4 Jupiter masses. So the deuterium burning limit does not uniquely identify the lower mass limit of the star formation process.

~From modeling it is also believed that in some cases it is possible for proto-planetary disk formation processes to lead to gas giants exceeding the deuterium burning limit - possibly up to ~25 Jupiter masses.

The two disadvantages above combine to result in a situation where there is a mass overlap range based upon formation mechanism.

My opinion is that conceptually it makes more sense to define Brown Dwarfs by formation mechanism. That would allow comparative studies between Brown Dwarfs and Gas Giant planets to see how much difference formation mechanism actually makes in the resulting structure and properties. However, the formation mechanism definition may not be practical at this time because determination of formation mechanism is difficult and formation mechanism studies are always evolving.

So I think the IAU's choice of 13 Jupiter masses is a practical solution at this time. But researchers probably should consider all bodies from 4 - 25 Jupiter masses as relevant to studies on formation and other aspects of Brown Dwarfs and Gas Giant Planets.

then how come on the NASA exoplanet archive it shows planets with masses much more than 13 Jupiter masses take a look at Kepler-297 d for example it says it has 282 Jupiter masses which is almost as massive as our sun yet they still call it an exoplanet

#10 russell23

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Posted 21 April 2024 - 09:45 AM

then how come on the NASA exoplanet archive it shows planets with masses much more than 13 Jupiter masses take a look at Kepler-297 d for example it says it has 282 Jupiter masses which is almost as massive as our sun yet they still call it an exoplanet

I'm not seeing that information for Kepler 297-d when I search the planet in the archive. Can you clarify where you are getting that number.  There is no row provided for the mass of that particular body.  The most recent radius estimate is 7.12 Earth radii so a mass exceeding Jupiter's mass is highly unlikely.   Red Dwarf stars start at a mass of 80 Jupiter masses so a mass of 282 Jupiter masses is not possible for a planet.   Here is the original paper announcing the NASA Exoplanet Archive:

 

https://ui.adsabs.ha.....989A/abstract

 

They indicated at that time that to be included in the archive it had to have an estimated mass less than or equal to 30 Jupiter masses.

 

You also have to keep in mind that the NASA exoplanet archive is separate from the IAU so they will include bodies that they think are potentially useful from a research perspective.  Including bodies up to 30 Jupiter masses in the exoplanet archive is a good approach.
 



#11 kingsbishop

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Posted 21 April 2024 - 08:38 PM

I'm not seeing that information for Kepler 297-d when I search the planet in the archive. Can you clarify where you are getting that number. There is no row provided for the mass of that particular body. The most recent radius estimate is 7.12 Earth radii so a mass exceeding Jupiter's mass is highly unlikely. Red Dwarf stars start at a mass of 80 Jupiter masses so a mass of 282 Jupiter masses is not possible for a planet. Here is the original paper announcing the NASA Exoplanet Archive:

https://ui.adsabs.ha.....989A/abstract

They indicated at that time that to be included in the archive it had to have an estimated mass less than or equal to 30 Jupiter masses.

You also have to keep in mind that the NASA exoplanet archive is separate from the IAU so they will include bodies that they think are potentially useful from a research perspective. Including bodies up to 30 Jupiter masses in the exoplanet archive is a good approach.

go to the NASA exoplanet catalog sorry I made a mistake there but go to the NASA exoplanet catalog and then when you see the list sort the list by mass from highest to lowest or either type in Kepler-297 d and it will show a ridiculous high mass

#12 RedLionNJ

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Posted 21 April 2024 - 10:52 PM

go to the NASA exoplanet catalog sorry I made a mistake there but go to the NASA exoplanet catalog and then when you see the list sort the list by mass from highest to lowest or either type in Kepler-297 d and it will show a ridiculous high mass

I agree, kingsbishop. The NASA exoplanet web page on this particular body makes no sense.  It quotes a radius of about 2/3 that of Jupiter, yet a mass of (very specifically) 282 times that of Jupiter.

 

If I were a scientist, I'd be disregarding information from that source.



#13 russell23

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Posted 22 April 2024 - 11:16 AM

go to the NASA exoplanet catalog sorry I made a mistake there but go to the NASA exoplanet catalog and then when you see the list sort the list by mass from highest to lowest or either type in Kepler-297 d and it will show a ridiculous high mass

It is still not popping up for me in that context.   When I sort by mass the first object on the list is PH2 b and the mass indicated is <80 Jupiter masses.  When I go into the Kepler catalog the object KOI-2513.1 is the most massive object and has a mass of 23.2 +/-2 Jupiter masses.

 

Ok - I just figured it out.  I am using the NASA Exoplanet Archive.  You are using the NASA Exoplanet Catalog.  They are two completely different sites.

 

I don't know where the "Catalog" is getting that number.  There are no mass estimates for this planet provided on the NASA Exoplanet Archive which sites this as the discovery paper for this planet:

 

https://ui.adsabs.ha......28V/abstract

 

As you can see in the abstract this planet is one of 69.  The data provided includes a period of 150.02 days and a radius of 7.12 Earth radii.  It is possible that whoever is updating the Catalog website used one of the various mass-radius models and calculated a mass from that.  However, that would likely involve two mistakes: First, the mass they calculated would have to be in Earth masses, not Jupiter masses for that number to make any sense.  Second, if that number is supposed to be Earth masses then it still doesn't make sense because planets with radii <~7.5 are not gas giants (fraction H-He will be less than 50%) and will have a mass less than 100 Earth masses.

 

The planet's radius would be consistent with a gas-rich Neptune composition and probably has a mass in the range 15 - 45 Earth masses.  I base that mass estimate on a sample I've been keeping of planets with equilibrium temperature < 600 Kelvin and low uncertainty in the mass and radius estimates.

 

At any rate, you can ignore that 282 Jupiter mass estimate.  It is an error however it ended up on the table on that site. 



#14 kingsbishop

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Posted 23 April 2024 - 02:20 AM

It is still not popping up for me in that context. When I sort by mass the first object on the list is PH2 b and the mass indicated is <80 Jupiter masses. When I go into the Kepler catalog the object KOI-2513.1 is the most massive object and has a mass of 23.2 +/-2 Jupiter masses.

Ok - I just figured it out. I am using the NASA Exoplanet Archive. You are using the NASA Exoplanet Catalog. They are two completely different sites.

I don't know where the "Catalog" is getting that number. There are no mass estimates for this planet provided on the NASA Exoplanet Archive which sites this as the discovery paper for this planet:

https://ui.adsabs.ha......28V/abstract

As you can see in the abstract this planet is one of 69. The data provided includes a period of 150.02 days and a radius of 7.12 Earth radii. It is possible that whoever is updating the Catalog website used one of the various mass-radius models and calculated a mass from that. However, that would likely involve two mistakes: First, the mass they calculated would have to be in Earth masses, not Jupiter masses for that number to make any sense. Second, if that number is supposed to be Earth masses then it still doesn't make sense because planets with radii <~7.5 are not gas giants (fraction H-He will be less than 50%) and will have a mass less than 100 Earth masses.

The planet's radius would be consistent with a gas-rich Neptune composition and probably has a mass in the range 15 - 45 Earth masses. I base that mass estimate on a sample I've been keeping of planets with equilibrium temperature < 600 Kelvin and low uncertainty in the mass and radius estimates.

At any rate, you can ignore that 282 Jupiter mass estimate. It is an error however it ended up on the table on that site.

it’s not just that planet that they stuffed up go to the NASA exoplanet catalog and then scroll down and click exoplanet catalog then you will see a list of exoplanets then click on the mass list so it sorts it by mass from most massive to least massive and you will see there are a bunch of exoplanets that they have stuffed up the mass on

#15 KBHornblower

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Posted 23 April 2024 - 10:15 AM

it’s not just that planet that they stuffed up go to the NASA exoplanet catalog and then scroll down and click exoplanet catalog then you will see a list of exoplanets then click on the mass list so it sorts it by mass from most massive to least massive and you will see there are a bunch of exoplanets that they have stuffed up the mass on

Are you arguing that we have detected exoplanets that are not massive enough to meet the clearing criterion?



#16 russell23

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Posted 23 April 2024 - 11:10 AM

it’s not just that planet that they stuffed up go to the NASA exoplanet catalog and then scroll down and click exoplanet catalog then you will see a list of exoplanets then click on the mass list so it sorts it by mass from most massive to least massive and you will see there are a bunch of exoplanets that they have stuffed up the mass on

Yeah -I just wouldn't use that website.  The NASA Exoplanet Archive or exoplanets.eu are better websites with accurate information.  They also link to the papers the data comes from so you can look it over if you need.



#17 kingsbishop

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Posted 23 April 2024 - 10:29 PM

Yeah -I just wouldn't use that website. The NASA Exoplanet Archive or exoplanets.eu are better websites with accurate information. They also link to the papers the data comes from so you can look it over if you need.

even exoplanet.eu have some bugs too if you sort it by mass you will find 24 exoplanets above 60 Jupiter masses including one of those 24 with a mass of 136 Jupiter masses and then also it includes Luhman 16 A&B as exoplanets when they are obviously brown dwarfs but adleast they fix bugs as soon as possible all it takes is one email and they fix it however nasa is so exclusive and they don’t fix anything.

I also don’t like how I have to type in the HD catalog for exoplanets like Pollux b or Beta Andromeda b on the NASA exoplanet catalog

Then that leaves us with the NASA exoplanet archive which is pretty laggy


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