# Questions tagged [coordinate]

Questions on systems to uniquely determine position of a point or other geometric element on a manifold such as Euclidean space.

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### Is this description of ecliptic times correct?

I did a brief write-up as a pet research project to explore astro-geological calculation and visualisation for Muslim prayer times. It's not meant to be authoritative (either scientifically or ...
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### Calculate geographical location (latitude, longitude) from horizontal and equatorial coordinates, date and UT

Lets say I found myself in the middle of nowhere with small computer with some sort of offline astrometry engine (like locally installed astrometry.net). I have some sort of mount that precisely tells ...
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### Current sources for astronomical equation coefficients

For a project I needed to implement some of the code to calculate the position of the sun and moon. To do this I'm using Meeus. Everything is working but in doing so I've started to wonder about the ...
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### Implementing polar coordinates correctly in solar system model?

I am working on a 2d solar system model using Python, but I'm unsure if my implementation of planet data is correct. I have the planet data stored in polar form (distance, velocity and angle), and I ...
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### How to flatten 3d astronomical coordinates into 2d polar form in Python

I first asked this at Stack Overflow but got redirected here I am making a 2d simulation of the solar system. For that you need a starting point for all planets. Right now I am storing that data in ...
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### Correct longitude from longitude over 180°

Last week, one of my exercise tasks was about determining the an observer's position on Earth, when in their zenith is a certain star with known right ascension and declination. We were supposed to ...
1 vote
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### How to find the constellation in which the sun is located using the night sky map?

The following sky map was given as part of practice problems in my Astronomy course The moon is in its first quarter phase. I am supposed to find the approximate date and time of the year in which ...
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### Difference in results between JPL Horizons and cspice (rust-spice)

I am calculating the apparent planetary position of planets using the cspice library (I am specifically using rust-spice, which is a wrapper of cspice in Rust). when I calculate the same values in the ...
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### How to describe the Sun's location to an alien from our Galaxy?

Let's say you got to the planet orbiting other star in our Galaxy through the wormhole. You think that the travel was instant but you're not 100% sure and it is not exactly known. The planet is ...
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### How to plot object on the map correctly

I am wondering how is it possible to plot the celestial object on the map I have attached if I only know following data: 16h 41m 41,24s 36° 27′ 35,5″
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### Are the rotational axes of Earth and Mars parallel?

So I was stuck on a question involving the transformation of coordinates from geocentric to Mars-centric coordinates. The relative position of Mars and its orbital details are given. I thought that we ...
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### How can non-earth-orbiting satellite coordinates be obtained by amateurs?

Just a few hours ago the moon-bound spacecraft Chandrayaan-3 was launched. While it will orbit Earth for a few days, it is accelerating/changing its orbit often to prepare for the transfer to a lunar ...
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### How to determine errors in coordinates from SIMBAD error ellipse

How to determine errors in ICRS coordinates from the SIMBAD error ellipse, please? Thank you
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### Right ascension - Gaia vs Simbad

What is the difference between Right ascension in Simbad and Gaia Archive, please? How to convert the values? For instance, HD 37468: 05h 38m 42.0s vs 84.68652242854718 deg. Should not be these values ...
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### Problem in converting equatoral coordinates to ecliptic coordinates

I would like to convert equatoral coordinates to ecliptique coordinates. I am following the source below: Practical Astronomy with Your Calculator The formula I am using is: When I solve this example,...
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### Which mobile/computer application can help me understand celestial coordinate systems better? [closed]

I wish to understand Equatorial and Altazimuth coordinate systems much better. Any applications or softwares which can help me out with the same?
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### Measurement unit of coordinate systems in astronomy

Nearly all of the coordinate system I have studied in Positional astronomy use the degree system. This makes me curious about why astronomers prefer degrees over radians as we know that Radian is a ...
1 vote
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### Astrometry and Geometric Distortions

CCD's are widely used for astrometry. Since a spherical surface (the celestial sphere) is projected onto a rectangular surface, the plate scale or pixel scale (approximated with 1/focal length etc) is ...
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### Calculating the angular momentum of stars from Gaia archive (Gaia DR3)

I am trying to calculate the angular momentum for a subset of stars from Gaia DR3. I have scanned the available fields in their database and could only find out the below fields that specifies the ...
1 vote
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### How are the lines from objects onto the ecliptic called?

See this screenshot from SpaceEngine: Many other examples from websites etc. Do they have a name? I couldn't find anything. If I'm not mistaken, those should be the z-coordinate of galactic ...
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### Using setting circles on a German Equatorial mount

Recently I have been working on equatorial grid system consisting of the right ascension and declination coordinates. Even after understanding the concept behind those coordinates, I am puzzled by the ...
1 vote