Questions tagged [algorithm]

Questions about a stepwise procedure to solve logical and/ or mathematical problems.

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12 votes
2 answers
3k views

How (the heck) does Astrometry.net work?

What magic is this? This answer to my question Astronomy detective question: what part of the sky are these photos of? What are a few of the stars? nails it, and the output (linked there) contains ...
uhoh's user avatar
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2 votes
2 answers
608 views

Calculation of Julian day is off for negative dates

I bought the book Astronomical Algorithms by Jean Meuss and I am reading it in order to build a small library I will use for another project. I made a program in Rust to calculate the JD given a date ...
Mattia Procopio's user avatar
2 votes
2 answers
2k views

What is exactly the "longitude of the perigee"

Some moon phase calculation algorithms (apparently derived from Duffet-Smith's book, example here) seem to use a parameter called "longitude of perigee at epoch". What exactly is this? Can I assume ...
ubik's user avatar
  • 123
11 votes
2 answers
333 views

Can automatic algorithms completely eliminate the impact of Starlink and other satellites?

According to a comment by user @J: With that said, other than aesthetics, machine vision algorithms are wildly more advanced today than in the past - strategies to remove passing satellites don't ...
JonathanReez's user avatar
10 votes
1 answer
146 views

How actively is Deep Learning being used in exoplanet identification?

Papers, like this one from Google, show that Deep Learning and Machine Learning are effective in detecting exoplanets from luminosity data provided by telescopes like TESS or Kepler. These models ...
user avatar
6 votes
1 answer
1k views

How to calculate the moon's illuminated fraction tilt?

I use "Astronomical algorithms" book by Jean Meeus for programming algorithms for the moon data calculations. I've already created a lot of methods but stuck on the calculation of the moon's ...
Andrey Zagoruyko's user avatar
3 votes
4 answers
473 views

Sunset and sunrise formulas adopted by IAU

I'm developing a C++ computer library with the formulas in the book "Practical Astronomy with your Calculator or Spreadsheet 4th Edition" but I have a problem with the formula 49, "...
VansFannel's user avatar
2 votes
0 answers
259 views

How the heck does JPL actually do the numerical integration for their development ephemerides? (general questions)

After writing this answer to JPL Horizons - "highly accurate measurements of planetary positions" - how do they do it? which draws from Park, Folkner, Williams & Boggs 2021 The JPL ...
uhoh's user avatar
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2 votes
2 answers
1k views

Jean Meeus - calculating moon rise, transit and set times - help isolating error in logic

I've been working my way through the Jean Meeus Astronomical Algorithms book for a few weeks, to implement some of the key algorithms for a personal project. This task has been a little more complex ...
Stew's user avatar
  • 21
2 votes
1 answer
127 views

How do they know the non-uniformities seen on the disk of π¹ Gru are real and not artifacts?

@RobJeffries' answer to What is this web on the surface of the Sun? explains why convection cells on some other stars can be far larger than they are on our Sun and includes a near-infrared VLT ...
uhoh's user avatar
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0 votes
2 answers
280 views

Mapping illumination to moon phase (font) icon

I use algorithms that give me the moon phase, age and illumination (and more) for a given timestamp and location. I am struggling to map that information to a (font) icon of the Moon Phases font. Each ...
Marcel Stör's user avatar