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Questions tagged [skyfield]

Skyfield high precision scientific astronomy library for Python and NumPy

The Skyfield project provides a modern alternative to the elderly PyEphem astronomy library for Python. Instead of requiring a custom C extension to be built or installed, Skyfield does all of its computation in pure Python and requires only the NumPy high performance numeric library in order to do its work — making Skyfield perfect for developers who can install NumPy directly, or who use scientific distributions that install NumPy automatically.

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Trying to calculate direction in sky of planets at a given time, but getting incorrect answers?

I'm trying to write a program to calculate what planets are above the horizon at a given time, and the direction in the sky the planets are, but I'm getting incorrect results. My code is below, does anyone have any idea what the issue might…
tgs123
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itrs reference frame in skyfield

I want to convert a Skyfield Topos object (lat/lon/altitude) to Earth Centered Earth Fixed (ECEF) coordinates. [][1]https://rhodesmill.org/skyfield/positions.html#coordinates-in-other-reference-frames gives the example: from skyfield.framelib import…
burningbright
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Detection of satellites in the telescope frame

I have the celestial coordinates of the center of telescope image, the telescope's field of view (in seconds), the start time of taking photo (full date), and the exposure time (in seconds). And I want to know how many Starlink satellites can get…
Oliver Wayne
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Trying to use pyinstaller with skyfield, building .exe but failing to run

I am trying to package up a script with pyinstaller that uses the skyfield module/API, and it builds, but when I run it, it dies saying it can't find nutation.npz (a data file included in the nutationlib.py _arrays = load_bundled_npy('nutation.npz')…
lostfox
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Azimuth/Altitude discrepancy between PyEphem and Skyfield

I cannot resolve why I am getting a different azimuth/altitude for a comet calculation between PyEphem and Skyfield, yet the right ascension and declination match. Code example: #!/usr/bin/env python3 # External verification: #…
Bernmeister
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Invalid results with script that uses skyfield

I'm exploring the possibilities of the magnificent software Skyfield by Brandon Rhodes. I've made a script to calculate conjunctions in Right Ascension between random objects. I use the following script: from skyfield import almanac from…
wie5Ooma
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Path between two Topos() locations: determine latitude and longitude where a given altitude is reached

I am quite new to field of orbital mechanics and currently struggling a bit with the following problem, which should be quite easy to solve with Skyfield, yet I am a bit overwhelmed by all the different coordinate systems and the translation between…
pezett
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how to convert degrees minutes seconds to decimal degrees (python/skyfield)

I woud like to extract coordinate of a satellite (ISS) in decimal by using this code: from skyfield.api import EarthSatellite, Topos, load import time line1 = '1 25544U 98067A 14020.93268519 .00009878 00000-0 18200-3 0 5082' line2 = '2 25544 …
knam
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How to parallelize calculations of celestial bodies motion?

I have a piece of code which calculates positions of some satellites and planets using Skyfield. For clarity, I use Pandas DataFrame as a container of positions and corresponding time moments. I want to make calculation parallel, but always getting…
lazySeal
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Get phase of day based on solar altitude/azimuth

As per the skyfield documentation online, I am able to calculate whether a given time of day is day or night. import skyfield.api import skyfield.almanac ts = skyfield.api.load.timescale() ephemeris = skyfield.api.load('de421.bsp') observer =…
Atif
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How can I use Skyfield or PyEphem to determine the dates of past Quintuple Conjunctions?

I am attempting to write a python script that will use the SkyField and SciPy libraries to find quintuple planetary conjunctions... Specifically I am looking for the date when the 5 visible planets were all in conjunction within the constellation of…
Joshua Besneatte
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Different ecliptic values of from_altaz() and observe(sun).apparent().ecliptic_latlon()

At Sunrise sun is supposed to be at the horizon (ie 0 degree altitude at east). but if I check ecliptic longitude of: the sun at sunrise and from_altaz() of zero degrees east I get different values for both. But is it not supposed to be the…
AviD1511
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Is there a replacement for "readtle" in skyfield to pull each entry from TLE files?

I would like to pull and parse the data for individual satellites from the TLE files at celestrak.com using Python. I found code to do so with pyephem using "readtle" but this does not work in skyfield. How can I pull the data from the tle files…
spacelaw
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Difference in sun-earth distance with compute(date) and compute(observer)

In the code below, computing the earth-sun distance with pyephem agrees well with the one compute from skyfield when using sun.compute(date), but not when doing sun.compute(obs) with obs an observer on earth at the same date. Is this because in the…
Seb
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find mean node of a planet/satellite using skyfield

I would like to be able to find mean node of a planet/satellite. It is quite different from this question in the sense that I am looking for nodes between the mean ecliptic of a date and the moon (or any other celestial body, but let's stay…
stackcats
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