I have an idea on how to find the ninth planet .

[Michael Kieth Adams]

Document the area of space where we think it might be, multiple times.  At some point it should block out a star or other astronomical object.  There might be quite a lot of orbiting junk in similar orbits but once one knows a target we should be able to tell if it is something else or a planet.  There are probably tons of scientists already doing this.

 

[Franklin]

The ninth planet was discovered in 1930 by Clyde Tombaugh. In 2006 Pluto had it's planetary status revoked when astronomers found that there were many more smaller objects out beyond the orbit of Neptune in the Kuiper belt. 

[Marvin Jenkins]

I am in favour of Pluto being the ninth planet as I grew up with the sky like that.

It is a perfect spheroid  but my understanding is that it was kicked off the planet list because of its orbit. I read somewhere that at one point its orbit is inside Neptune's? 

Not to mention how we classify anything orbiting farther out than Pluto. There is a suggestion backed by observation that TNOs are orbiting in a way that shows they are being shepherded by a large unknown body.

Marv

[Nik271]

I believe it's planet X OP is talking about. The problem is that the area of sky the models suggest is too big and the chance of occultation of a star is very small. It's better to look for movement but at these magnitudes (mag 20 or more ) you need big telescopes which means small fields of view, expensive telescope time, so the search is still going on.

Edited January 27 by Nik271

[vlaiv]

4 minutes ago, Nik271 said:

I believe it's planet X OP is talking about. The problem is that the area of sky the models suggest is too big and the chance of occultation of a star is very small. It's better to look for movement but at these magnitudes (mag 20 or more ) you need big telescopes which means small fields of view, expensive telescope time, so the search is still going on.

I wonder if telescopes such as RASA line could be used for that?
These are wide field scopes - they can cover large area of the sky, and they can do it relatively "fast".

[Marvin Jenkins]

I would contend that most if not all instruments are not looking for X.

Clyde Tombaugh found Pluto with equipment that is considered almost stone age by modern standards.

I understand that there are billion dollar systems doing all sky surveys on a 24 hrs basis but planet X is not what they are designed to find.

Also just saying... Planet X might not exist at all. 

M

[Marvin Jenkins]

2 minutes ago, vlaiv said:

I wonder if telescopes such as RASA line could be used for that?
These are wide field scopes - they can cover large area of the sky, and they can do it relatively "fast".

Would a wide field instrument be the thing to find a 20 mag or dimmer object?

[vlaiv]

1 minute ago, Marvin Jenkins said:

Would a wide field instrument be the thing to find a 20 mag or dimmer object?

I'm more concerned with lack of resolution of such instrument rather than it's FOV.

FOV is just a bonus as it allows to search more sky using the same exposure. Narrow field telescopes need to take multiple separate exposures to cover the same part of the sky, so wide field is clearly a plus here as it allows for faster search.

Resolution in terms of pixel size is not the issue either - but resolution in terms of optical performance is. RASA telescopes have rather high star FWHM (compared to diffraction limited optics of the same aperture) and I'm afraid that in dense star fields - multiple faint stars will blend together and mask any sort of object that is present.

[John_D]

Never mind planet X, I'm still holding out for Vulcan, Einstein be damned 😁

[Marvin Jenkins]

Just as topic of conversation. What if the idea that a distant gravitational object is shepherding the TNOs cannot be seen optically. What if it is a black hole?

I have often wondered why you move farther from our greatest gravitational mass you seem to find more and more material. We look farther out of our solar system and find more questionable planets. This seems at odds to me as the sun being the only sculpture of our solar system.

Marv

[Marvin Jenkins]

To add more. I was watching a Brian Cox video about explanet research and it turns out that planetary systems like ours are extremely rare compared to what has been observed.

In fact we are an extremely rare set of circumstances. Why is that, when many of the systems should be similar?

[Marvin Jenkins]

I will say that a Brian Cox video and twenty minutes thinking does not constitute an original thought. Educated people, please step in.

[Michael Kieth Adams]

I can’t believe so many people commented so fast.  The area is large and the chances of a star being blocked by Planet X might be remote but a long distance or perhaps deeper view should be full of objects and blank spots might be spotted.  I know that there are few telescopes capable of this available.  I also realize that Planet X might be multiple planetoids, or something else entirely, but I would think a planet would be more likely.  Infrared might work but there would be a huge area to look through.  Maybe the best idea is to get better measurements of  orbits and narrow things down a lot.  That would also not be cheap, but it would be cool to figure out exactly where it has to be and have it be there!

[Cosmic Geoff]

No need to deploy fresh hardware. There are many present and past sky surveys, e.g. PanSTARRS and Gaia.  Anyone looking for anomalous objects could trawl through the vast amount of data already accumulated.

I agree with the revisionist view that Pluto is a minor planet.  I have managed to image and identify it a couple of times.

[johnturley]

On 27/01/2024 at 20:05, Franklin said:

The ninth planet was discovered in 1930 by Clyde Tombaugh. In 2006 Pluto had it's planetary status revoked when astronomers found that there were many more smaller objects out beyond the orbit of Neptune in the Kuiper belt. 

Interestingly I understand Clyde Tombaugh tracked down Pluto in 1930, based on predictions by Percival Lowell which were based on the gravitational impact of the suspected Planet 9 on the orbits of Uranus and Neptune. In fact it had actually been imaged 15 years earlier in 1915, but missed apparently because one image fell on a flaw in the photographic plate, and in the other it was too close to a brighter star to be identified. According to Percival Lowell's calculations, to have these impacts Planet 9 should have a mass similar to that of the earth, and a diameter of around 8,000 miles.

Following observations with the then new 200in Palomar Telescope, the diameter of Pluto was revised down from 8,000 to 3,600 miles, and following later observations from spacecraft and the Hubble Space Telescope was then revised down further to only 1,400 miles, less than half the size of Mercury, and smaller than the Earth's moon, and less than 1% of the earth's mass, so it couldn't have had the gravitational impacts that supposedly led to its discovery. This therefore leaves a bit of a mystery as to how Pluto was tracked down in the first place, and its discovery close to the predicted position is now put down to being a bit of coincidence. 

John 

Edited January 30 by johnturley

[Michael Kieth Adams]

I just reread the responses.  I have cataracts and  need to use a magnifying glass to see better(yes I also use 2.5 magnifying glasses but they only do so much)  the member from Serbia, if I understood him correctly said that a wide view might overpower a relatively small blockage, but isn’t this how we find exoPlanets?  There would be differences in light intensity even if not a clear shadow.   I know we are talking about significant expense but this is our home, we should know about the back rooms.

[Michael Kieth Adams]

It has also occurred to me that a passing object might have disturbed the orbits and then gone on its merry way.  Be pretty sad if we wind up looking for something no longer there!  All knowledge has value.

[Bugdozer]

22 hours ago, Marvin Jenkins said:

I am in favour of Pluto being the ninth planet as I grew up with the sky like that.

It is a perfect spheroid  but my understanding is that it was kicked off the planet list because of its orbit. I read somewhere that at one point its orbit is inside Neptune's? 

Not to mention how we classify anything orbiting farther out than Pluto. There is a suggestion backed by observation that TNOs are orbiting in a way that shows they are being shepherded by a large unknown body.

Marv

Pluto failed to meet the criterion of being gravitationally dominant in its orbit, I believe because its orbit crosses over with Neptune's. 

However, this makes me question whether Neptune should therefore also be eliminated for the same reason. It hasn't managed to boot Pluto off, so... 

[Bugdozer]

On 27/01/2024 at 19:42, Michael Kieth Adams said:

Document the area of space where we think it might be, multiple times.  At some point it should block out a star or other astronomical object.  There might be quite a lot of orbiting junk in similar orbits but once one knows a target we should be able to tell if it is something else or a planet.  There are probably tons of scientists already doing this.

 

There's a fundamental problem with detecting an object purely by occultation. You would need at least one more, and preferably several more occultations to determine an orbit. The advantage of a visible object, even if it's faint, is you will always be able to see it. If we detected an object by occultation, but then didn't see any further occultations, you have then pretty much lost it entirely. It could have gone anywhere at any speed. 

Edited January 28 by Bugdozer

[Ags]

23 minutes ago, Bugdozer said:

Pluto failed to meet the criterion of being gravitationally dominant in its orbit, I believe because its orbit crosses over with Neptune's. 

However, this makes me question whether Neptune should therefore also be eliminated for the same reason. It hasn't managed to boot Pluto off, so...

Pluto is 1/10,000 the mass of Neptune. From Pluto's point of view it hasn't started clearing it's orbit. From Neptune's point of view Pluto is just the moon that got away 

Edited January 28 by Ags

[Bugdozer]

1 minute ago, Ags said:

Pluto is 1/1000 the mass of Neptune. From Pluto's point of view it hasn't started clearing it's orbit. From Neptune's point of view Pluto is just the moon that got away 

That doesn't really address my point. 

[Ags]

Edited my earlier post with the correct ratio: 1/10,000. No body in the Solar System has removed everything from its orbit. Even Jupiter has thousands of sizeable asteroids sharing its orbit. Earth has a few bits bouncing around in its Lagrange points.

[Paul M]

I've given up looking for the 9th planet, I don't think it'll ever be found. So I've started looking for the 10th planet instead...

[Mircea]

The 9th planet probably don't exist.

In 2019 I wrote an article published in the Romanian astronomical magazine ''Pasi spre infinit''. The article contain my survey of the status of the search and research for Planet 9, up to 2019.

One of the results was a bit unexpected. Virgil Scurtu , noted amateur astronomer in our country and author of astronomical books, sent me his view on the issue of Planet 9.

He expressed some criteria regarding the birth of a planet in the outskirts of the Solar System. Those criteria do not forbid the birth of a planet in those conditions but is making the process highly unlikely.

The possibility left open is the caption process proposed by Alexander Mustil from Lund University. According to Mustil, if Planet 9 exist, it may be a planet captured by the Sun while still being in the ''maternal'' star cluster.

This hypothesis is really troubling because it would make Planet 9 the most interesting object to study.

No, not for aliens but because it would be the first massive object born outside the Solar System and in our reach.

 

In attachment is the page of the article containing ''the criteria of Scurtu'', numbered from (1) to (4). 

The article is in Romanian language and I didn't wrote an update or a translation.

 

It was mentioned the names of Percival Lowell and Clyde Tombaugh, related to Pluto/ Pluton in Romanic languages.

I would like only to add that the quest for Planet 9 was started by a hypothesis of French astronomer Camille Flammarion.

 

Mircea

[johnturley]

14 hours ago, Ags said:

Pluto is 1/10,000 the mass of Neptune. From Pluto's point of view it hasn't started clearing it's orbit. From Neptune's point of view Pluto is just the moon that got away 

At one time Pluto was thought to be an escaped moon of Neptune, and its 'escape' was supposed to be what caused Triton to circle Neptune retrograde, however I don't think that theory is in favour anymore. 

John 

Edited January 29 by johnturley