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Exoplanets

These are exomoons, not exoplanets.
The orbital periods are much too short to allow otherwise.
Planets whipping around a star in 5 days??!?!
Pshaw.

Likely you are seeing a very faint star (like Jupiter) with it's many moons.
Scale can be hard to discern, to say the least! :D
 
dorsetknob said:
Exomoons orbit exoplanets ( which orbit Stars )
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Is there a well-known example of an exo-anything with orbital periods on order of those seen in our solar system?
In other words, I understand what you are saying... I am suggesting what you take to be a star (yes, true) is on the order of the size of Jupiter, say, with it's many moons as we all know...

That's not a planet, baby.... THAT'S A MOON! Exomoon.
Sidebar: "That's no moon! It's a space station!" -- some dork

I would also add our best telescopes can only peer about 350 "light-years" into the cosmos.
So there is absolutely no basis for calling something 1,500,000 light-years away or whatever. Absurd.
 
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FCG said:
These are exomoons, not exoplanets.
The orbital periods are much too short to allow otherwise.
Planets whipping around a star in 5 days??!?!
Pshaw.

Likely you are seeing a very faint star (like Jupiter) with it's many moons.
Scale can be hard to discern, to say the least! :D
Click to expand...

There is one hot gas giant, if I remember correctly, which orbits around its parent star every 4 days. I've searched for it - it's 51 Pegasi b. There are probably more examples of such planets with extremely short orbital period.
 
Komshija said:
There is one hot gas giant, if I remember correctly, which orbits around its parent star every 4 days. I've searched for it - it's 51 Pegasi b. There are probably more examples of such planets with extremely short orbital period.
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Not planets. Moons. A planet orbiting a star in 4 days? Come on, man.
Even Mercury, our closest-in planet, requires 88 days to complete a revolution around Sol.

Now where might we see orbital periods measured in days?

Well, here's some (moons of Jupiter):

Satellite -- Orbital Period (Earth Days)
Io -- 1.769 days
Europa -- 3.551 days
Ganymede -- 7.155 days
Callisto -- 16.689 days

hmmm... pretty close to Europa, one of the many moons of Jupiter

BTW, Jupiter is a hot gas gaint :wtf:
 
FCG said:
Not planets. Moons. A planet orbiting a star in 4 days? Come on, man.
Even Mercury, our closest-in planet, requires 88 days to complete a revolution around Sol.

Now where might we see orbital periods measured in days?
.......
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Technically speaking, Komshija and Drone are correct.
51 Pegasi b (abbreviated 51 Peg b), unofficially dubbed Bellerophon, later named Dimidium, is an extrasolar planet approximately 50 light-years away in the constellation of Pegasus. It was the first exoplanet to be discovered orbiting a main-sequence star,[1] the Sun-like 51 Pegasi, and marked a breakthrough in astronomical research. It is the prototype for a class of planets called hot Jupiters.
According to the link, it's an Extrasolar Planet, and an exoplanet.
 
Ahhzz said:
Technically speaking, Komshija and Drone are correct.
51 Pegasi b (abbreviated 51 Peg b), unofficially dubbed Bellerophon, later named Dimidium, is an extrasolar planet approximately 50 light-years away in the constellation of Pegasus. It was the first exoplanet to be discovered orbiting a main-sequence star,[1] the Sun-like 51 Pegasi, and marked a breakthrough in astronomical research. It is the prototype for a class of planets called hot Jupiters.
According to the link, it's an Extrasolar Planet, and an exoplanet.
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That would make the base system a binary pair as a "hot Jupiter" is a star, not a planet.
The 4 day orbital period is a dead give away in that case as a planet orbiting a star at that rate you would think would be ripped apart.
Show me another planet with a 4-day orbital period around a star, please, or anywhere in that ballpark.
We can, rather, as I have pointed out above, find moons with orbital periods measured in days.
I think the confusion lies in calling Jupiter a planet. It's more like a star.
 
FCG said:
That would make the base system a binary pair as a "hot Jupiter" is a star, not a planet.
The 4 day orbital period is a dead give away in that case as a planet orbiting a star at that rate you would think would be ripped apart.
Show me another planet with a 4-day orbital period around a star, please, or anywhere in that ballpark.
We can, rather, as I have pointed out above, find moons with orbital periods measured in days.
I think the confusion lies in calling Jupiter a planet. It's more like a star.
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Where did you read it orbits in 4 days?? More like 12 years!
Jupiter.png
 
Ah, thought you were on about Jupiter itself, I need to read more carefully. Still not sure how you decided it's a star, you're good at thinking outside the box that's for sure.
 
On topic:

According to wiki

An exoplanet orbiting red dwarf star TYC 9486-927-1 has the longest known orbital period (~1000000 years). Holy sh... 1 million years. Oh my … And it's >4500 AU from its star.

Exoplanet with shortest known orbital period is around SWIFT J1756.9-2508 pulsar. (4.31 hours)
 
@FCG
https://www.merriam-webster.com/dictionary/star
See definition 1a & 1b
https://www.merriam-webster.com/dictionary/planet
See definition 1a(1) and 1a(2)
https://www.merriam-webster.com/dictionary/moon
See definition 1c

FCG said:
Correct.
I added that Europa, a moon of Jupiter
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Wait a moment, you said earlier;
FCG said:
Likely you are seeing a very faint star (like Jupiter)
Click to expand...
So if Jupiter is a star, very faint or otherwise, it doesn't have moons. By your logic, Europe would be a planet.

So which is it? Is Jupiter a planet or a star?

Allow me help you out with that. A star is any mass object that is or has at some point in the past had a process of fusion going on in it's core. Jupiter is not a star as it has never nor will it ever have fusion reactions taking place. Jupiter is a planet and it's satellites are moons.

Exoplanets are satellites of stars. Exomoons are satellites of exoplanets. See how that works? Simple logic that gives order and understanding to those parts of the universe. You really need to stop with the transparent & blatant shoveling of disinformation. You're embarrassing yourself and causing needless nonsense here on TPU.
 
infrared said:
Ah, thought you were on about Jupiter itself, I need to read more carefully. Still not sure how you decided it's a star, you're good at thinking outside the box that's for sure.
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The outer "planets" being Jupiter, Saturn, Uranus, Neptune are all very star-like.
They are separate and distinct from the inner rocky planets being Mercury, Venus, Earth, Mars.
Separating these two sets of 4 planets each is what we call the Main Asteroid belt as this is where a majority of asteroids hang out.
There are asteriods further out, remnants of the many supernova that have occurred already in this solar system, distributed in a 3D sphere about the solar system that we call the Oort cloud (see attached).
Look, they even included Ceres in this mock-up.

At the center of each planet is a portion of a white dwarf core which was destroyed when the spacial (we'll call it Substance A) star went supernova and fractured and destroyed the nearby temporal (Substance B) white dwarf star included in that binary pair.

The outer planets (across the asteroid boundary) are lighter gases and are gravitating and condensing more fuel as they move their way up the main sequence. Uranus and Neptune, already blue in color, and near the end of their lives and will supernova again relatively soon. Much of the heavier elements closer to the center of the supernova accumulated on the white dwarf core fragments that are the 4 inner planets much more.

Every planet is a star at the core. So are moons. White dwarf (Substance B star) cores being what would be described as an inside-out Substance A star. White dwarf stars have their lightest elements increasingly found going inward towards the center with the heavier elements gravitating to the surface.

P.S. I agree, Pluto is not a planet and is more akin to an asteroid.

Potato, tomato...

solsys.png


lexluthermiester said:
Allow me help you out with that. A star is any mass object that is or has at some point in the past had a process of fusion going on in it's core.
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Stars don't fusion, they fission.

lexluthermiester said:
Exoplanets are satellites of stars. Exomoons are satellites of exoplanets. See how that works?
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Oh, I get it. Depends on what you want to call a planet.
Planets at one point were referred to as wandering stars.
 

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Drone said:
On topic:

According to wiki

An exoplanet orbiting red dwarf star TYC 9486-927-1 has the longest known orbital period (~1000000 years). Holy sh... 1 million years. Oh my … And it's >4500 AU from its star.

Exoplanet with shortest known orbital period is around SWIFT J1756.9-2508 pulsar. (4.31 hours)
Click to expand...

Someone been watching this thing for awhile then, huh?
How far away was this star and exoplanet exactly?
What would be the degree of arc subtended during the period of this observation, within the measurable degree of certainty, to allow for such a preposterous calculation? Help me out.

Planet around a star in 4 hours? Whoa... wild ride. Literally... hang on.

What's your next trick, star spinning at 1,475,756 RPM?

lexluthermiester said:
Oh?
https://www.merriam-webster.com/dictionary/fusion
See definition 3
https://www.merriam-webster.com/dictionary/fission
See definition 1 and 3

Stars fuse atoms into heavier atoms.

Nuclear weapons and radioactive decay break apart large atoms into smaller atoms.

A thought has occurred. It is entirely possible that you do not understand the depth of your own ignorance. This has suddenly become very fascinating!
Click to expand...

Indeed.
I've been known to dabble in nuclear engineering.
 
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lexluthermiester said:
Doubtful or you would have known the difference. Rookie mistake..

Those two processes are very different and are indeed completely opposite.
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The same environment which would allow for fusion to take place also allows for fission to take place.

The problem begins in defining the atom.
The atom is a 3D temporal rotation in time at a location in space.
It is a compound motion which can be modeled using a dual rotating system of quaternions.
It is not made of up constituent protons and neutrons and electrons all just hanging out with each other for the heck of it.

Just because you can using EM accelerate particles to fantastical speeds approaching the speed of light (really you are lessening the "drag" of gravity and allowing the particle to achieve "default speed of the progression" (c, or the "speed of light) and smash them together and watch all the fragments come out does it mean those fragments go back together like humpty-dumpty.
 
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FCG said:
What's your next trick, star spinning at 1,475,756 RPM?
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Sry for short off-topic, but:

https://www.nrao.edu/pr/2006/mspulsar/

Not quite a million RPM, but 42960 RPM.

FCG said:
The same environment which would allow for fusion to take place also allows for fission to take place.
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The environment for both fusion and fission taking place has equal properties, but both processes have very different requirements and outcomes and thus should not be confused.
 
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Dinnercore said:
The environment for both fusion and fission taking place has equal properties, but both processes have very different requirements and thus should not be confused.
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Yeah, here's a different property: fission has been demonstrated self-sustaining... fusion, not so much.

Here's a good summary of the State of the Art, straight from Wiky-P!:
https://en.wikipedia.org/wiki/Fusion_ignition

"Experts believe that achieving fusion ignition is the first step towards the potentially limitless energy source that is nuclear fusion."

Translation: Not yet! But we're really trying!
 
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