Deep Sky Object: Handle velocities properly#222
Merged
rhannequin merged 1 commit intomainfrom Oct 20, 2025
Merged
Conversation
a0fc3cd to
c1a4c70
Compare
5df2e29 to
ce09e72
Compare
c1a4c70 to
fbedc28
Compare
In the initial implementation, the astrometric and apparent velocities were off as they were not geocentric but represented the object's intrinsic velocity. This is fixed now to match the fact that in Astronoby, astrometric and apparent reference frames are geocentric. Note: apparent velocity is slightly off compared to Skyfield and Astropy. This is because Astronoby applies precession and nutation corrections to the velocity, which apparently Skyfield and Astropy do not. This was kept this way as this makes sense for planets.
ce09e72 to
9226969
Compare
Merged
rhannequin
added a commit
that referenced
this pull request
Oct 31, 2025
## 0.9.0 - 2025-10-31 _If you are upgrading: please see [UPGRADING.md]._ ### Features * Add `#approaching_primary?` and `#receding_from_primary?` to solar system bodies ([#211]) * Calculate apoapsis and periapsis events ([#213]) * Improve precision of ΔT ([#219]) * Deep Sky Object: Compute astrometric position ([#217]) * Deep Sky Object: Compute apparent position ([#220]) * Deep Sky Object: Handle velocities properly ([#222]) * Deep Sky Object: Compute topocentric position ([#226]) * Deep Sky Object: difference between the body and the position ([#227]) * Deep Sky Object: Add support for RiseTransitSetCalculator ([#228]) ### Improvements * Drop `Astronoby::Apparent#angular_diameter` ([#221]) * Bump rubyzip from 3.0.2 to 3.2.1 by @dependabot ([#210], [#215], [#223], [#233]) * Bump standard from 1.50.0 to 1.51.1 by @dependabot ([#212], [#214]) * Be proud about the precision achieved ([#218]) * Use local apparent instead of local mean sidereal time for hour angle ([#225]) * Bump rspec from 3.13.1 to 3.13.2 by @dependabot ([#229]) * Bump benchmark from 0.4.1 to 0.5.0 by @dependabot ([#230]) * Add documentation for deep-sky objects ([#232]) * Bump rake from 13.3.0 to 13.3.1 by @dependabot ([#235]) ### Backward-incompatible changes * Drop `Astronoby::Apparent#angular_diameter` ([#221]) * Use local apparent instead of local mean sidereal time for hour angle ([#225]) **Full Changelog**: v0.8.0...v0.9.0 [#210]: #210 [#211]: #211 [#212]: #212 [#213]: #213 [#214]: #214 [#215]: #215 [#217]: #217 [#218]: #218 [#219]: #219 [#220]: #220 [#221]: #221 [#222]: #222 [#223]: #223 [#225]: #225 [#226]: #226 [#227]: #227 [#228]: #228 [#229]: #229 [#230]: #230 [#232]: #232 [#233]: #233 [#235]: #235 [UPGRADING.md]: https://github.com/rhannequin/astronoby/blob/main/UPGRADING.md
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
In the initial implementation, the astrometric and apparent velocities were off as they were not geocentric but represented the object's intrinsic velocity.
This is fixed now to match the fact that in Astronoby, astrometric and apparent reference frames are geocentric.
Note: apparent velocity is slightly off compared to Skyfield and Astropy. This is because Astronoby applies precession and nutation corrections to the velocity, which apparently Skyfield and Astropy do not. This was kept this way as this makes sense for planets.