Questions tagged [orbit]

Questions regarding an object 'falling around' another object, due to a combination of gravity and momentum.

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11
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2answers
1k views

What is the longest natural bound orbit chain observed?

Define a bound orbit chain as a list of successively less massive bodies, each in a bound orbit with the bodies preceding it in the list. Then an example of a bound orbit chain would be: <Sun, ...
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1answer
76 views

Where can I find a list of retrograde Milky Way stars?

I read in papers that the Milky Way contains some retrograde stars (retrograde to the Milky Way rotation). Does anybody know where I can find a list of them, possibly including data on their distance ...
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1answer
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Error propagation methods for orbit parameters

Recently I've encountered an article in our local astronomical popularization magazine. It is about a well known task of Sgr A*-black hole's mass estimation. The article is written as a step by step ...
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1answer
56 views

The definition of eclipsing binary star systems

In the second minimum (the 3rd step) there is a smaller decrease in light intensity. For this to happen, wouldn't you need to be looking at the plane of orbit from above rather than directly along the ...
4
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1answer
93 views

Any known Triple Star Systems with this hierarchy?

I'm curious, are there any known STABLE triple systems in which a close inner binary pair is orbited by a more massive star, yet the total mass of the binary pair is greater than that single orbiting ...
3
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1answer
51 views

What is the longitude of the winter solstice for the various planets?

I am looking for data showing the longitude at which the various planets in the solar system reach their winter solstice. Where could I find this data?
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0answers
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What is the period of the 'cycle' of Earth's ecliptic variation, relative to the 'invariable plane'? 70,000 or 100,000 years?

The plane of Earth's path around the Sun, the ecliptic, is different from the average of the solar system's as a whole (the invariable plane) by about 1.57°.... Our path around the Sun, though, goes ...
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2answers
124 views

Estimating close approach between all asteroids themselves

I am currently writing a C++ program to show asteroids in 3D, and find close approaches or collisions. I got my orbital elements from JPL https://ssd.jpl.nasa.gov/sbdb_query.cgi. So far so good, with ...
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2answers
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Is S2 still the fastest known star in the galaxy?

Wikipedia's entry for the star S2 says that it has the fastest known ballistic orbit, reaching speeds exceeding 5,000 km/s (11,000,000 mph, or ​1⁄60 the speed of light) and acceleration of about 1.5 ...
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1answer
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Orbit of Luhman 16?

I am studying some binary stars and brown dwarfs. Some orbits are known and easy to find, like Alpha Centauri. However, when I look for the orbital characteristics of Luhman 16 (AB), I only get the ...
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1answer
367 views

How to find the shape of an orbit

What is the minimum information I need to be able to draw the shape of an orbit of a body that orbits the sun? With this information how can I figure out the shape of its orbit?
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1answer
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How can I find the width of an orbit knowing some values?

I need to find the width/x-radius of an orbit, which is ellipse shaped, knowing variables like the orbit's length(perihelion + aphelion in this case) and the eccentricity. I am not sure if this is ...
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3answers
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Computing the rate of orbital decay

We know that the estimated time until a binary system merges is given by: $$\dfrac{5c^5r^4}{256G^3(m_1m_2)(m_1+m_2)}$$ But what is the formula to determine rate of decay, in some sort of distance unit,...
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2answers
183 views

What is the thickness of the Solar System disk?

What is the thickness in AU of the all planets' orbital plane height combined in the Solar System? Excluding Pluto. Looking for h
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6answers
19k views

Why doesn't the sun pull the moon away from earth?

If the suns gravitational pull is strong enough to hold much larger masses in place (all the planets) and at much greater distances (all planets further away from the sun then earth) why does it not ...
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1answer
60 views

Prograde to retrograde orbital path

Is there a planet or planetary moon flyby path that could send a solar prograde orbiting asteroid into a retrograde solar orbit?
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2answers
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Kepler's Law, focal points - Heliocentric or Barycentric?

It is known that all the mass in the Solar system moves around the Barycenter. For the two focal points in Kepler's law; is the first focal point $F_1$ a Heliocenter? Or is it actually a Barycenter? ...
3
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1answer
358 views

2 Earth-like planets in co-orbital configuration

I am trying to set up 2 Planets in a co-orbital configuration around a Jupiter size planet similarly to Saturn's moons Janus and Epimetheus. I'm trying to do this in Universe Sandbox 2 but when I ...
3
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2answers
93 views

Do moons experience periods of no sunlight when orbiting “behind” their planet?

I'm writing a story that takes place on the Saturn moon Iapetusand I was thinking that especially since Iapetus only has an inclination of about 17 degrees from the ecliptic, wouldn't there be a point ...
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6answers
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What makes protoplanetary disks start rotating? (Initial energy needed to rotate)

Planets form from a protoplanetary disk that has been rotating around its star. The initial energy that makes them rotate really matters to me. Why did the protoplanetary disk start rotating around ...
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3answers
600 views

How much magnetic attraction is there between the Sun and Earth?

How much magnetism is there between the Earth and Sun? Would the distance from the Sun differ for not the Earth iron core and how much?
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2answers
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What makes a star? [closed]

What are the properties of a star? How do astronomers classify the properties of stars?
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1answer
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How can orbital resonance sometimes have a stabilising effect, whilst other times, it has a destabilising effect?

I have just started learning about orbital resonance. I understand how bodies in orbital resonance will line up according to the orbital ratio number, and there will be increased gravitational effects ...
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6answers
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If the Sun disappeared, could some planets form a new orbital system?

If the sun were to suddenly disappear, the planets would continue to travel tangentially to their former orbits. (This I know from this answer to a somewhat related question here.) In such a scenario, ...
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1answer
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Fate of a planet orbiting a Lagrange point behind a star?

Let's say there is a planet orbiting at L5 behind a star, which is in turn orbiting a more massive star, like so: What is the ultimate fate of this planet? I'm predicting that it will spiral into the ...
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Visual binary star with circular apparent orbit

Does anyone know a good example of visual (or interferometric) binary star apparent orbit of which looks circular due to projection though in fact is markedly elliptical? I need that for teaching.
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4answers
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Aligning the equinoxes to the cardinal points on a circular calendar

I want to draw a calendar as a circle, with the equinoxes at the top and bottom, and the solstices at the left and right. I am prepared to accept a little inaccuracy by having exactly 365 or 366 days ...
2
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1answer
104 views

Scholarly work on the gravitational disruption of a rocky planet by a close pass with another planet?

note: While the apparently abandoned question Effects of a rogue planet passing between the Earth and the Moon? (inspired by Thundarr the Barbarian) asks for speculation and was answered with it, this ...
3
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1answer
44 views

How long before Phobos reaches the Roche limit of Mars?

Phobos orbits really close to Mars, so close that one Phobos period is shorter than one sol. Due to tidal friction, it is also getting closer and closer to Mars. How much time will it take before ...
3
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2answers
120 views

What are the Time Zones on Mercury?

I normally post on worldbuilding, but this question is merely about facts of a planets orbit and spin. I am trying to figure out how time periods work on Mercury to possibly make a worldbuilding guide ...
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1answer
123 views

Simulates Orbit [duplicate]

I IT developer, and I would code a small program that simulates the orbit of two bodies, the problem of two bodies eventually. I have no problem on the part programming but I have a little trouble ...
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1answer
950 views

Finding the radius of an eccentric orbit at any point

Knowing the apoapsis, periapsis and therefore period of an orbit, how can I find the radius of an object in an orbit at a given angle or time, whichever is needed. For example, if I have an object m ...
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1answer
111 views

Can Kepler's 3rd Law be applied in higher dimensions to describe orbits (quadric surfaces)?

Motivation for asking: The 2-D orbital path of a celestial body revolving around another celestial body due to the force of gravity can be described by a conic section; this is the curve formed by ...
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1answer
646 views

Astrodynamic Canonical Units [closed]

Maybe this is more appropriate for the Physics or Maths, but anyway. I am struggling with applying Canonical units with formulas. I am struggling specifically with how they are used, am I to convert ...
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1answer
3k views

Why aren't all planets in the same plane?

Obviously all planets are not in same perfect plane. Because if at all they were in the exact same plane, it would mean that Mercury transits and Venus transits would not be that rare. Any ...
3
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2answers
365 views

Does the earth spiral around the sun's movement/motion path?

I have watched the following video (How Earth Moves by Vsauce) regarding how earth moves: Here are some screenshots: I have some questions: Does the earth spiral ...
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0answers
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Do the orbits of planets change? Where is the data for this?

Everything in the space is moving all the time. Do the orbit of major Solar Systems planets, Mercury to Saturn change? Just like Moon's orbit around Earth changes. How often, how small or big is the ...
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3answers
121 views

If an orbit is shifting due to orbital precession, is it still a Keplerian orbit?

I was thinking about orbits a few days ago, and realized that orbits shift/precess naturally. Given that a two-body problem with a star and a planet, if the planet has an eccentric orbit that ...
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1answer
1k views

How long does a comet “live”?

When a comet loses all his volatile material after many orbits around the Sun, it becomes a "dead" comet (like an asteroid, a centaur or whatever), see for example 2015 TB145. Is there any ...
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0answers
30 views

Classical Mechanics : Interaction Sun Radiation Pressure - Gravitation

I have a theoretical problem that merges the effects of a gravitational field and the Sun radiation pressure. The problem goes as follows: A spacecraft orbits the Sun in absence of any other body ...
12
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1answer
864 views

Does anyone know why three of Jupiter's largest moons orbit in 1:2:4 resonance?

Three of the first four moons ever discovered outside of our own planetary sphere of gravitational influence orbit in very close to perfect resonance. Europa's orbit is almost exactly twice as long as ...
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Sun's and planets' inclination to the Invariable plane

What are the inclinations of all major Solar system planets (Mercury to Pluto) to the invariable plane? Looking for accurate data calculated on them. Also, What is the inclination of the Sun to the ...
27
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6answers
9k views

The moon has just the right speed not to crash on the Earth or escape into space. What are the odds?

My understanding is that the moon was created a long time ago when Earth was hit by a big asteroid. The debris then agglomerated into the Moon, which happens to be orbiting at the exact speed required ...
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0answers
59 views

Moon's and nodes' inclination to the Invariable plane

Moon is inclined to the ecliptic 5.14 degrees. Earth's inclination to the invariable plane is 1.57869 degrees. What is the Moon's, and node's inclination to the invariable plane? Since the Moon has an ...
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2answers
767 views

Calculating the Angular Momentum of a planet

I want to calculate the Angular Momentum of any planet at any point on the orbit around the Sun. Example: I want to calculate the Angular Momentum of Pluto today, on Jan 27, 2021 00:00:00 Hrs Where ...
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4answers
3k views

Is it at all possible for the sun to revolve around as many barycenters as we have planets in our solar system?

Though it is understandable that the sun and the earth may be revolving around a barycenter, but, if so, not only the sun and Jupiter should also be revolving around some barycenter, the same should ...
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3answers
3k views

What are the odds that the Sun hits another star?

The Sun moves around the Milky Way disk in the same direction as most of the other stars in our galaxy (prograde). But there are a number of older stars in the galactic halo that move in retrograde ...
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0answers
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Why can't ESA/NASA build a handful of Gaia telescopes and launch them into different positions in space for better accuracy?

I've noticed that many stars in GAIA DR2 have highly uncertain distances. Why can't a space agency send multiple Gaia spacecraft into orbit around different places (One in L2 Earth, one in ...
5
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1answer
260 views

If two stars collide, what is the probability that they merge to form a single star?

After looking at What are the odds that the Sun hits another star? and answering it (crudely), now I'd like to ask the following: What is the probability that if two stars collide, their cores merge ...
5
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1answer
54 views

Does a star's rotation always match a planet's orbit?

For a planet orbiting a star, is it ever possible for a star to be rotating in the opposite way on it's own axis compared to the planet that is orbiting the star? Or do gravitational forces mean the ...

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