Questions tagged [orbital-elements]

Questions about the parameters needed to specify the characteristics of an orbit.

24 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
5 votes
0 answers
172 views

Why does the tropical year have a ~161 years cycle?

Using PyEphem, I calculated the time difference between consecutive summer solstices in the south hemisphere for the last 4000 years, and plotted them in a graph. It seems like random noise around the ...
ordptt's user avatar
  • 173
5 votes
0 answers
80 views

A couple of questions about Earth's hypothetical planetary rings

From what little I know of this subject, It should be possible for Earth (Or a planet the size of Earth) to keep a system of Planetary Rings. However, looking around the internet only gives me info ...
Erik Mækir's user avatar
5 votes
0 answers
76 views

Are occultation observations used/useful for orbit determination?

The IAU Minor Planet Center lists $(486958)\space 2014 \space MU_{69}$ "Ultima Thule" as having an uncertainty parameter of 2, based on the observation arc of 851 days, from its discovery in 2014, to ...
costrom's user avatar
  • 207
4 votes
0 answers
205 views

How to determine the time of periastron passage (T) of a single lined spectroscopic binary?

I am working on finding spectroscopic elements of a single lined spectroscopic binary. All I have is irregularly spaced radial velocity data which needs to be phase folded to plot a velocity curve (RV ...
ShaunakP's user avatar
4 votes
0 answers
65 views

Has the inclination of the orbital plane of Phobos and Deimos followed that of Mars' axial tilt?

Phobos and Deimos are very close to Mars' equatorial plane (the inclination of their orbits is roughly 1°). The axial tilt of Mars has changed a lot over time, and might have had a inclination of over ...
usernumber's user avatar
  • 17.5k
3 votes
0 answers
97 views

Kepler to Cartesian and Cartesian to Kepler inaccuracies

I am programming a computer simulation set in a star system. I've used Rene Schwarz's wonderfully concise memorandi explaining converting from Kepler orbital elements into cartesian coordinates and ...
w94n9's user avatar
  • 51
3 votes
0 answers
60 views

Precision of orbital period of exoplanets vs solar system planets (Extrasolar Planets Encyclopedia)

I noticed that the Extrasolar Planets Encyclopedia lists the orbital period of L 98-59 b in days to 7 decimal places. Can astronomers really measure orbital period of exoplanets to greater precision ...
sno's user avatar
  • 1,457
3 votes
0 answers
612 views

Earth-Centered Earth-Fixed coordinates with respect to heliocentric coordinate system at vernal equinox

I am trying to calculate the position of a point on the Earth's surface with respect to the Sun's center at a certain date and time. For what I am trying to do it is OK to ignore precession of Earth's ...
Abstraction's user avatar
2 votes
0 answers
112 views

Code for Gauss's method orbit determination

I'm trying to calculate the state vectors of the ISS using Gauss's method with three sets of values (right ascension, declination and sidereal time). I'm following the method described in "...
specimen_n1l3's user avatar
2 votes
0 answers
89 views

Find position of orbiting body along orbit efficiently

I'm coding a game, and a fundamental mechanic is celestial bodies moving in elliptical, Keplerian orbits around a single gravitational point in a planetary system (not our solar system). The bodies ...
w94n9's user avatar
  • 51
2 votes
0 answers
63 views

Is there an orbit around the earth that experiences a total solar eclipse by the Moon at least every month?

Is there a way to design an earth orbit so that it passes through the Moon's umbra with greater frequency than total solar eclipses occur on earth's surface? What is the maximum frequency of eclipses ...
vwoods's user avatar
  • 21
2 votes
0 answers
246 views

What is the relationship between true anomaly and solar longitude?

So, my ultimate objective is to map solar longitude values onto a pseudo-Gregorian calendar. I thought this would be simple, but it has turned out to be anything but. I have asked several questions on ...
Grant Hartlage's user avatar
2 votes
0 answers
292 views

What's the formula for change in argument of periapsis over time due to J2 perturbations for a geocentric satellite?

I'm trying to propagate the orbit of the ISS, but it became very clear to me very quickly that the J2 perturbations were nothing to scoff at. A quick google search gave me the equation for the change ...
Martin Leung's user avatar
2 votes
0 answers
79 views

When an object revolves around an oblate planet, in near-circular orbit, does the oblateness ALWAYS make it moves FASTER?

tl;dr: The orbital period for a Keplerian orbit of a small body around a massive one with standard gravitational parameter $\mu=GM$ and semi-major axis $a$ is given by $$T = 2\pi\sqrt{\frac{a^3}{\mu}}....
Ng Ph's user avatar
  • 488
2 votes
0 answers
64 views

Based on discoveries of new TNOs since 2016, is planet Nine still necessary to explain the TNO's orbits?

It is almost five years since the announcement of the likelyhood of another planet that is responsible for clustering eTNO's orbits, very close perihelia of detached dwarf planets to the Sun, and high ...
Greenhorn's user avatar
  • 397
2 votes
0 answers
102 views

Does habitable zone take tidally locked bodies into account?

Imagine a tidally locked planet orbiting a red dwarf, where habitability is not situated close to terminator zone, but on a "small" cap normal to incident starlight (zenith) with permanent average +15 ...
user avatar
1 vote
0 answers
59 views

How likely are triple planet systems?

Is it likely to ever discover three planets of similar mass revolving around a common barycenter, or would such a system be too unstable? Such triple planet system would look like a triangle once in a ...
Giovanni's user avatar
  • 145
1 vote
0 answers
54 views

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.
Leos Ondra's user avatar
  • 1,065
1 vote
0 answers
82 views

Orbital Mechanics: where can I find initial conditions for orientations and angular rates of planets in our solar system?

I am looking to write the equations of motion (EOMs) for a 6DOF analysis of our solar system. I want to integrate the equations forward in time, and need a complete set of initial conditions to do so....
Josh's user avatar
  • 19
1 vote
0 answers
127 views

How to draw an orbit from Orbital Elements using Transform3DGroup

I am trying to draw an orbit using the Transform3DGroup class in the C# .NET framework. I have orbital elements a, e, i, RAAN, ArgPer, trueAnom. The algorithm that spits these out for me also gives me ...
a_here_and_now's user avatar
1 vote
0 answers
244 views

How to convert a function of keplerian elements to a function of equinoctial elements?

I need to convert the Keplerian orbital elements to the equinoctial elements and then use the converted elements"equinoctial" in the function "d" below. To do this, first, I converted the Keplerian ...
Ery's user avatar
  • 11
1 vote
0 answers
251 views

How do I calculate the hour angle of a planet's moon from a point on that planet's surface?

I'm worldbuilding and I'm trying to construct a standing stone calendar that'll accurately denote where to look for my planet's moon at its four major phases from 53.8 degrees South. So, I need the h0,...
Rúnatál Davino's user avatar
1 vote
0 answers
192 views

Ecliptic plane, its precise definition useful for calculations

My question is similar to the one posted by Abtract, whom however never got a useful answer. I am trying to calculate from scratch the exact times of sunrise and sunset anywhere on earth taking into ...
Jens's user avatar
  • 121
0 votes
0 answers
50 views

The possibility of rapidly changing the Earths orbit via a passing astronomical object

I assume that the Earth could be “gently” (without colossal tidal or volcanic catastrophe) displaced by a passing extra solar star, brown dwarf or planet and end up perhaps 10% further away from the ...
Slarty's user avatar
  • 349