Why does the Sun have different day lengths, but not the gas giants? The Next CEO of Stack OverflowDoes the Sun rotate?What is the long term fate of the gas giants?Why are gas giants colored the way they are?Why don't storms on gas giants move to the poles, like hurricanes on Earth do?Why do the gas giants in the Solar System have comparatively large orbits compared to the inner planets?Why do our clocks not go out of sync with the day over a year?Could binary gas giants have ring and moon systems?Does the Sun have permanent geographical features?Are harmonic relationships among the rotation periods of the planets well known? Are they factors in other planetary phenomena?Modeling planet rotations (time of day, obliqueness, etc.)
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Why does the Sun have different day lengths, but not the gas giants?
The Next CEO of Stack OverflowDoes the Sun rotate?What is the long term fate of the gas giants?Why are gas giants colored the way they are?Why don't storms on gas giants move to the poles, like hurricanes on Earth do?Why do the gas giants in the Solar System have comparatively large orbits compared to the inner planets?Why do our clocks not go out of sync with the day over a year?Could binary gas giants have ring and moon systems?Does the Sun have permanent geographical features?Are harmonic relationships among the rotation periods of the planets well known? Are they factors in other planetary phenomena?Modeling planet rotations (time of day, obliqueness, etc.)
$begingroup$
The Sun's rotation period varies from about 25 days at the equator to about 38 days at the poles. As I understand it, this is because the Sun is not solid, and because of the way centripetal force works, the equator must move faster than the poles.
Question: if this works, why do Jupiter/Saturn/Uranus/Neptune have well-defined days? Why don't the equators of these planets rotate faster than the poles as well? For example, Wikipedia's article on Jupiter gives the length of a Jovian day as 9h 55m 30s, which is so precise that it implies Jupiter does not have a rotational period which varies with latitude.
the-sun rotation gas-giants
asked Mar 22 at 2:38
AllureAllure
582311
$endgroup$
add a comment |
$begingroup$
The Sun's rotation period varies from about 25 days at the equator to about 38 days at the poles. As I understand it, this is because the Sun is not solid, and because of the way centripetal force works, the equator must move faster than the poles.
Question: if this works, why do Jupiter/Saturn/Uranus/Neptune have well-defined days? Why don't the equators of these planets rotate faster than the poles as well? For example, Wikipedia's article on Jupiter gives the length of a Jovian day as 9h 55m 30s, which is so precise that it implies Jupiter does not have a rotational period which varies with latitude.
the-sun rotation gas-giants
asked Mar 22 at 2:38
AllureAllure
582311
$endgroup$
add a comment |
$begingroup$
The Sun's rotation period varies from about 25 days at the equator to about 38 days at the poles. As I understand it, this is because the Sun is not solid, and because of the way centripetal force works, the equator must move faster than the poles.
Question: if this works, why do Jupiter/Saturn/Uranus/Neptune have well-defined days? Why don't the equators of these planets rotate faster than the poles as well? For example, Wikipedia's article on Jupiter gives the length of a Jovian day as 9h 55m 30s, which is so precise that it implies Jupiter does not have a rotational period which varies with latitude.
the-sun rotation gas-giants
asked Mar 22 at 2:38
AllureAllure
582311
$endgroup$
The Sun's rotation period varies from about 25 days at the equator to about 38 days at the poles. As I understand it, this is because the Sun is not solid, and because of the way centripetal force works, the equator must move faster than the poles.
Question: if this works, why do Jupiter/Saturn/Uranus/Neptune have well-defined days? Why don't the equators of these planets rotate faster than the poles as well? For example, Wikipedia's article on Jupiter gives the length of a Jovian day as 9h 55m 30s, which is so precise that it implies Jupiter does not have a rotational period which varies with latitude.
the-sun rotation gas-giants
the-sun rotation gas-giants
asked Mar 22 at 2:38
AllureAllure
582311
asked Mar 22 at 2:38
AllureAllure
582311
asked Mar 22 at 2:38
AllureAllure
582311
asked Mar 22 at 2:38
AllureAllure
582311
asked Mar 22 at 2:38
AllureAllure
582311
582311
add a comment |
add a comment |
1 Answer
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$begingroup$
It's a matter of how "day" is defined.
Wikipedia's article on Jupiter cites this IAU/IAG paper for the length of a Jupiter day. In it, footnote (e) of table I has the following:
The equations for W for Jupiter, Saturn, Uranus and Neptune refer to the rotation of their magnetic fields (System III)
The radio emissions of the gas giants have well-defined periodic variations. These variations are caused by the rotation of the magnetic fields of those planets, and are evidence that they have a reasonably coherent core of some sort that's rotating at a uniform speed. The periodic variations then represent the rotation speed of that object, which is taken as the rotation speed of the planet.
We're reasonably certain the Sun doesn't have a coherent core. Measuring the variation of the magnetic field doesn't show a well-defined period, and doesn't provide a useful definition of the Sun's rotation speed.
answered Mar 22 at 3:14
MarkMark
1,874920
$endgroup$
4
$begingroup$
I just add that for Jupiter there is definitively no a fix day based on std rotation. At least no for the outer layer. It does even rotate in stripes and a simulation as in Celestia package is a kind of spectacle.
$endgroup$
– Alchimista
Mar 22 at 8:08
6
$begingroup$
“The assumption is that whatever's generating the magnetic field forms a reasonably coherent mass that's rotating at a uniform speed.” — I’d strengthen this by pointing out that it’s not just an assumption, it’s based closely on empirical facts: the magnetic field has a measurable uniform periodic behaviour, and based our understanding of planetary magnetic fields, we’re confident this corresponds to rotation of a somewhat coherent core. With the sun, as I understand it, we don’t see any uniformly periodic behaviour that we would expect to correspond to some kind of rotating mass.
$endgroup$
– Peter LeFanu Lumsdaine
Mar 22 at 13:37
1
$begingroup$
The Sun's magnetic field don't have a period as @PeterLeFanuLumsdaine stated.
$endgroup$
– Mindwin
Mar 22 at 14:06
add a comment |
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1 Answer
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1 Answer
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active
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$begingroup$
It's a matter of how "day" is defined.
Wikipedia's article on Jupiter cites this IAU/IAG paper for the length of a Jupiter day. In it, footnote (e) of table I has the following:
The equations for W for Jupiter, Saturn, Uranus and Neptune refer to the rotation of their magnetic fields (System III)
The radio emissions of the gas giants have well-defined periodic variations. These variations are caused by the rotation of the magnetic fields of those planets, and are evidence that they have a reasonably coherent core of some sort that's rotating at a uniform speed. The periodic variations then represent the rotation speed of that object, which is taken as the rotation speed of the planet.
We're reasonably certain the Sun doesn't have a coherent core. Measuring the variation of the magnetic field doesn't show a well-defined period, and doesn't provide a useful definition of the Sun's rotation speed.
answered Mar 22 at 3:14
MarkMark
1,874920
$endgroup$
4
$begingroup$
I just add that for Jupiter there is definitively no a fix day based on std rotation. At least no for the outer layer. It does even rotate in stripes and a simulation as in Celestia package is a kind of spectacle.
$endgroup$
– Alchimista
Mar 22 at 8:08
6
$begingroup$
“The assumption is that whatever's generating the magnetic field forms a reasonably coherent mass that's rotating at a uniform speed.” — I’d strengthen this by pointing out that it’s not just an assumption, it’s based closely on empirical facts: the magnetic field has a measurable uniform periodic behaviour, and based our understanding of planetary magnetic fields, we’re confident this corresponds to rotation of a somewhat coherent core. With the sun, as I understand it, we don’t see any uniformly periodic behaviour that we would expect to correspond to some kind of rotating mass.
$endgroup$
– Peter LeFanu Lumsdaine
Mar 22 at 13:37
1
$begingroup$
The Sun's magnetic field don't have a period as @PeterLeFanuLumsdaine stated.
$endgroup$
– Mindwin
Mar 22 at 14:06
add a comment |
$begingroup$
It's a matter of how "day" is defined.
Wikipedia's article on Jupiter cites this IAU/IAG paper for the length of a Jupiter day. In it, footnote (e) of table I has the following:
The equations for W for Jupiter, Saturn, Uranus and Neptune refer to the rotation of their magnetic fields (System III)
The radio emissions of the gas giants have well-defined periodic variations. These variations are caused by the rotation of the magnetic fields of those planets, and are evidence that they have a reasonably coherent core of some sort that's rotating at a uniform speed. The periodic variations then represent the rotation speed of that object, which is taken as the rotation speed of the planet.
We're reasonably certain the Sun doesn't have a coherent core. Measuring the variation of the magnetic field doesn't show a well-defined period, and doesn't provide a useful definition of the Sun's rotation speed.
answered Mar 22 at 3:14
MarkMark
1,874920
$endgroup$
4
$begingroup$
I just add that for Jupiter there is definitively no a fix day based on std rotation. At least no for the outer layer. It does even rotate in stripes and a simulation as in Celestia package is a kind of spectacle.
$endgroup$
– Alchimista
Mar 22 at 8:08
6
$begingroup$
“The assumption is that whatever's generating the magnetic field forms a reasonably coherent mass that's rotating at a uniform speed.” — I’d strengthen this by pointing out that it’s not just an assumption, it’s based closely on empirical facts: the magnetic field has a measurable uniform periodic behaviour, and based our understanding of planetary magnetic fields, we’re confident this corresponds to rotation of a somewhat coherent core. With the sun, as I understand it, we don’t see any uniformly periodic behaviour that we would expect to correspond to some kind of rotating mass.
$endgroup$
– Peter LeFanu Lumsdaine
Mar 22 at 13:37
1
$begingroup$
The Sun's magnetic field don't have a period as @PeterLeFanuLumsdaine stated.
$endgroup$
– Mindwin
Mar 22 at 14:06
add a comment |
$begingroup$
It's a matter of how "day" is defined.
Wikipedia's article on Jupiter cites this IAU/IAG paper for the length of a Jupiter day. In it, footnote (e) of table I has the following:
The equations for W for Jupiter, Saturn, Uranus and Neptune refer to the rotation of their magnetic fields (System III)
The radio emissions of the gas giants have well-defined periodic variations. These variations are caused by the rotation of the magnetic fields of those planets, and are evidence that they have a reasonably coherent core of some sort that's rotating at a uniform speed. The periodic variations then represent the rotation speed of that object, which is taken as the rotation speed of the planet.
We're reasonably certain the Sun doesn't have a coherent core. Measuring the variation of the magnetic field doesn't show a well-defined period, and doesn't provide a useful definition of the Sun's rotation speed.
answered Mar 22 at 3:14
MarkMark
1,874920
$endgroup$
It's a matter of how "day" is defined.
Wikipedia's article on Jupiter cites this IAU/IAG paper for the length of a Jupiter day. In it, footnote (e) of table I has the following:
The equations for W for Jupiter, Saturn, Uranus and Neptune refer to the rotation of their magnetic fields (System III)
The radio emissions of the gas giants have well-defined periodic variations. These variations are caused by the rotation of the magnetic fields of those planets, and are evidence that they have a reasonably coherent core of some sort that's rotating at a uniform speed. The periodic variations then represent the rotation speed of that object, which is taken as the rotation speed of the planet.
We're reasonably certain the Sun doesn't have a coherent core. Measuring the variation of the magnetic field doesn't show a well-defined period, and doesn't provide a useful definition of the Sun's rotation speed.
answered Mar 22 at 3:14
MarkMark
1,874920
edited Mar 22 at 19:55
answered Mar 22 at 3:14
MarkMark
1,874920
answered Mar 22 at 3:14
MarkMark
1,874920
answered Mar 22 at 3:14
MarkMark
1,874920
1,874920
4
$begingroup$
I just add that for Jupiter there is definitively no a fix day based on std rotation. At least no for the outer layer. It does even rotate in stripes and a simulation as in Celestia package is a kind of spectacle.
$endgroup$
– Alchimista
Mar 22 at 8:08
6
$begingroup$
“The assumption is that whatever's generating the magnetic field forms a reasonably coherent mass that's rotating at a uniform speed.” — I’d strengthen this by pointing out that it’s not just an assumption, it’s based closely on empirical facts: the magnetic field has a measurable uniform periodic behaviour, and based our understanding of planetary magnetic fields, we’re confident this corresponds to rotation of a somewhat coherent core. With the sun, as I understand it, we don’t see any uniformly periodic behaviour that we would expect to correspond to some kind of rotating mass.
$endgroup$
– Peter LeFanu Lumsdaine
Mar 22 at 13:37
1
$begingroup$
The Sun's magnetic field don't have a period as @PeterLeFanuLumsdaine stated.
$endgroup$
– Mindwin
Mar 22 at 14:06
add a comment |
4
$begingroup$
I just add that for Jupiter there is definitively no a fix day based on std rotation. At least no for the outer layer. It does even rotate in stripes and a simulation as in Celestia package is a kind of spectacle.
$endgroup$
– Alchimista
Mar 22 at 8:08
6
$begingroup$
“The assumption is that whatever's generating the magnetic field forms a reasonably coherent mass that's rotating at a uniform speed.” — I’d strengthen this by pointing out that it’s not just an assumption, it’s based closely on empirical facts: the magnetic field has a measurable uniform periodic behaviour, and based our understanding of planetary magnetic fields, we’re confident this corresponds to rotation of a somewhat coherent core. With the sun, as I understand it, we don’t see any uniformly periodic behaviour that we would expect to correspond to some kind of rotating mass.
$endgroup$
– Peter LeFanu Lumsdaine
Mar 22 at 13:37
1
$begingroup$
The Sun's magnetic field don't have a period as @PeterLeFanuLumsdaine stated.
$endgroup$
– Mindwin
Mar 22 at 14:06
4
4
$begingroup$
I just add that for Jupiter there is definitively no a fix day based on std rotation. At least no for the outer layer. It does even rotate in stripes and a simulation as in Celestia package is a kind of spectacle.
$endgroup$
– Alchimista
Mar 22 at 8:08
$begingroup$
I just add that for Jupiter there is definitively no a fix day based on std rotation. At least no for the outer layer. It does even rotate in stripes and a simulation as in Celestia package is a kind of spectacle.
$endgroup$
– Alchimista
Mar 22 at 8:08
6
6
$begingroup$
“The assumption is that whatever's generating the magnetic field forms a reasonably coherent mass that's rotating at a uniform speed.” — I’d strengthen this by pointing out that it’s not just an assumption, it’s based closely on empirical facts: the magnetic field has a measurable uniform periodic behaviour, and based our understanding of planetary magnetic fields, we’re confident this corresponds to rotation of a somewhat coherent core. With the sun, as I understand it, we don’t see any uniformly periodic behaviour that we would expect to correspond to some kind of rotating mass.
$endgroup$
– Peter LeFanu Lumsdaine
Mar 22 at 13:37
$begingroup$
“The assumption is that whatever's generating the magnetic field forms a reasonably coherent mass that's rotating at a uniform speed.” — I’d strengthen this by pointing out that it’s not just an assumption, it’s based closely on empirical facts: the magnetic field has a measurable uniform periodic behaviour, and based our understanding of planetary magnetic fields, we’re confident this corresponds to rotation of a somewhat coherent core. With the sun, as I understand it, we don’t see any uniformly periodic behaviour that we would expect to correspond to some kind of rotating mass.
$endgroup$
– Peter LeFanu Lumsdaine
Mar 22 at 13:37
1
1
$begingroup$
The Sun's magnetic field don't have a period as @PeterLeFanuLumsdaine stated.
$endgroup$
– Mindwin
Mar 22 at 14:06
$begingroup$
The Sun's magnetic field don't have a period as @PeterLeFanuLumsdaine stated.
$endgroup$
– Mindwin
Mar 22 at 14:06
add a comment |
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