chiron location

[tutucea]

from skyfield.constants import AU_KM
from skyfield.vectorlib import VectorFunction
from spktype21 import SPKType21

class Type21Object(VectorFunction):
    def __init__(self, kernel, target):
        self.kernel = kernel
        self.center = 0
        self.target = target

    def _at(self, t):
        k = self.kernel
        r, v = k.compute_type21(0, self.target, t.whole, t.tdb_fraction)
        return r / AU_KM, v / AU_KM, None, None

ts = load.timescale(builtin=True)
t = ts.utc(2020, 6, 9)

eph = load('de421.bsp')
earth = eph['earth']

kernel = SPKType21.open('ci/wld23593.15')
chiron = Type21Object(kernel, 2002060)

ra, dec, distance = earth.at(t).observe(chiron).radec()
print(ra)
print(dec) ```

``` python chiron.py 
Traceback (most recent call last):
  File "/home/ethan/Desktop/chiron.py", line 23, in <module>
    kernel = SPKType21.open('ci/wld23593.15')
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ethan/pipshitz/lib/python3.11/site-packages/spktype21.py", line 94, in open
    return cls(DAF(open(path, 'rb')))
                   ^^^^^^^^^^^^^^^^
FileNotFoundError: [Errno 2] No such file or directory: 'ci/wld23593.15'
(pipshitz) ethan@astrologyReadings ~/Desktop $ pip install spktype21
Requirement already satisfied: spktype21 in /home/ethan/pipshitz/lib/python3.11/site-packages (0.1.0)
(pipshitz) ethan@astrologyReadings ~/Desktop $ pip install SPKType21
Requirement already satisfied: SPKType21 in /home/ethan/pipshitz/lib/python3.11/site-packages (0.1.0)
```  i tried using HORIZON and create SPK and even that failed .. so i am a little lost 

[brandon-rhodes]

Let's start with the directory you have named: do you have a directory named ci/?

[tutucea]

no i do not ! but i just took care of all that and installed everything, naively i thought i do not need it .. still working on determining the position for chiron

[brandon-rhodes]

You may want to read more about various open() calls in Python and how / separates a directory name from a filename. If the directory does not exist, you will get an error trying to put a file there.

[tutucea]

pip install -r requirements.txt
Collecting https://github.com/brandon-rhodes/assay/archive/master.zip (from -r requirements.txt (line 14))
  Downloading https://github.com/brandon-rhodes/assay/archive/master.zip
     \ 26.0 kB 279.5 kB/s 0:00:00
  Preparing metadata (setup.py) ... done
Collecting astropy==3.2.2
  Downloading astropy-3.2.2.tar.gz (8.0 MB)
     ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 8.0/8.0 MB 3.7 MB/s eta 0:00:00
  Preparing metadata (setup.py) ... error
  error: subprocess-exited-with-error
  
  × python setup.py egg_info did not run successfully.
  │ exit code: 1
  ╰─> [179 lines of output]
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-0.4rc1 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning:  is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-0.4rc2 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-0.4rc3 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-0.4 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-0.4.1 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-0.4.2 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-0.4.3 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-0.4.4 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-0.4.5 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-0.4.6 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-0.4.7 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-0.4.8 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-1.0 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-1.0.1 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-1.0.2 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-1.0.3 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-1.0.4 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-1.0.5 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-1.0.6 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-1.0.7 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-1.1b1 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-1.1rc1 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-1.1rc2 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-1.1 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-1.1.1 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-1.1.2 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-1.2rc1 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-1.2 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-1.3rc1 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-1.3 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-1.3.1 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-2.0rc1 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-2.0 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-2.0.1 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-2.0.2 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-2.0.3 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-2.0.4 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-2.0.5 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-2.0.6 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-2.0.7 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-2.0.8 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-2.0.9 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-2.0.10 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-2.0.11 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-3.0rc1 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-3.0rc2 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-3.0 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-3.0.1 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-3.0.2 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-3.1rc1 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-3.1 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-3.1.1 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-3.2 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-3.2.1 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-3.2.2 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-4.0 is an invalid version and will not be supported in a future release
        warnings.warn(
      /home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: helpers-4.0.1 is an invalid version and will not be supported in a future release
        warnings.warn(
        error: subprocess-exited-with-error
      
        × python setup.py bdist_wheel did not run successfully.
        │ exit code: 1
        ╰─> [6 lines of output]
            usage: setup.py [global_opts] cmd1 [cmd1_opts] [cmd2 [cmd2_opts] ...]
               or: setup.py --help [cmd1 cmd2 ...]
               or: setup.py --help-commands
               or: setup.py cmd --help
      
            error: invalid command 'bdist_wheel'
            [end of output]
      
        note: This error originates from a subprocess, and is likely not a problem with pip.
        ERROR: Failed building wheel for astropy-helpers
      ERROR: Failed to build one or more wheels
      Traceback (most recent call last):
        File "/home/ethan/pycodes/venv/lib/python3.10/site-packages/setuptools/installer.py", line 82, in fetch_build_egg
          subprocess.check_call(cmd)
        File "/usr/lib/python3.10/subprocess.py", line 369, in check_call
          raise CalledProcessError(retcode, cmd)
      subprocess.CalledProcessError: Command '['/home/ethan/pycodes/venv/bin/python3', '-m', 'pip', '--disable-pip-version-check', 'wheel', '--no-deps', '-w', '/tmp/tmpt8mrsjn3', '--quiet', '--index-url', 'https://pypi.python.org/simple', 'astropy-helpers==3.2.2']' returned non-zero exit status 1.
      
      The above exception was the direct cause of the following exception:
      
      Traceback (most recent call last):
        File "/tmp/pip-install-v0rukwsx/astropy_7f59b4a34d6241afa11b36935c58b110/ah_bootstrap.py", line 556, in _do_download
          dist.fetch_build_eggs(req)
        File "/home/ethan/pycodes/venv/lib/python3.10/site-packages/setuptools/dist.py", line 812, in fetch_build_eggs
          resolved_dists = pkg_resources.working_set.resolve(
        File "/home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py", line 771, in resolve
          dist = best[req.key] = env.best_match(
        File "/home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py", line 1056, in best_match
          return self.obtain(req, installer)
        File "/home/ethan/pycodes/venv/lib/python3.10/site-packages/pkg_resources/__init__.py", line 1068, in obtain
          return installer(requirement)
        File "/home/ethan/pycodes/venv/lib/python3.10/site-packages/setuptools/dist.py", line 883, in fetch_build_egg
          return fetch_build_egg(self, req)
        File "/home/ethan/pycodes/venv/lib/python3.10/site-packages/setuptools/installer.py", line 84, in fetch_build_egg
          raise DistutilsError(str(e)) from e
      distutils.errors.DistutilsError: Command '['/home/ethan/pycodes/venv/bin/python3', '-m', 'pip', '--disable-pip-version-check', 'wheel', '--no-deps', '-w', '/tmp/tmpt8mrsjn3', '--quiet', '--index-url', 'https://pypi.python.org/simple', 'astropy-helpers==3.2.2']' returned non-zero exit status 1.
      
      During handling of the above exception, another exception occurred:
      
      Traceback (most recent call last):
        File "<string>", line 2, in <module>
        File "<pip-setuptools-caller>", line 34, in <module>
        File "/tmp/pip-install-v0rukwsx/astropy_7f59b4a34d6241afa11b36935c58b110/setup.py", line 12, in <module>
          import ah_bootstrap  # noqa
        File "/tmp/pip-install-v0rukwsx/astropy_7f59b4a34d6241afa11b36935c58b110/ah_bootstrap.py", line 944, in <module>
          BOOTSTRAPPER = _Bootstrapper.main()
        File "/tmp/pip-install-v0rukwsx/astropy_7f59b4a34d6241afa11b36935c58b110/ah_bootstrap.py", line 263, in main
          bootstrapper.run()
        File "/tmp/pip-install-v0rukwsx/astropy_7f59b4a34d6241afa11b36935c58b110/ah_bootstrap.py", line 345, in run
          dist = method()
        File "/tmp/pip-install-v0rukwsx/astropy_7f59b4a34d6241afa11b36935c58b110/ah_bootstrap.py", line 413, in get_local_directory_dist
          upgrade = self._do_upgrade(dist)
        File "/tmp/pip-install-v0rukwsx/astropy_7f59b4a34d6241afa11b36935c58b110/ah_bootstrap.py", line 593, in _do_upgrade
          return self._do_download(version=upgrade.version)
        File "/tmp/pip-install-v0rukwsx/astropy_7f59b4a34d6241afa11b36935c58b110/ah_bootstrap.py", line 578, in _do_download
          raise Exception(msg.format(DIST_NAME, source, repr(e)))
      Exception: Error retrieving astropy-helpers from PyPI:
      DistutilsError("Command '['/home/ethan/pycodes/venv/bin/python3', '-m', 'pip', '--disable-pip-version-check', 'wheel', '--no-deps', '-w', '/tmp/tmpt8mrsjn3', '--quiet', '--index-url', 'https://pypi.python.org/simple', 'astropy-helpers==3.2.2']' returned non-zero exit status 1.")
      [end of output]
  
  note: This error originates from a subprocess, and is likely not a problem with pip.
error: metadata-generation-failed

× Encountered error while generating package metadata.
╰─> See above for output.

note: This is an issue with the package mentioned above, not pip.
hint: See above for details.

[brandon-rhodes]

You will want to just pip install skyfield if you are trying to use Skyfield. AstroPy should not be necessary (and it looks like the attempt to install it is giving errors?).

[tutucea]

got it , can we get back to Chiron.. which file do i need to get the position for it .. ```
/Downloads/python-skyfield-master$ ls -a
. ci de421.bsp hip_main.dat.gz skyfield
.. CITATION.cff design LICENSE Table-S15.2020.txt
.agignore containers examples MANIFEST.in test-code.sh
authorities contrib FUNDING.yml .python-version test-docs.sh
bin Contrib.rst .github README.rst TODO.rst
builders .coveragerc .gitignore requirements.txt
CHANGELOG.rst de405.bsp hip_main.dat setup.py

[brandon-rhodes]

got it , can we get back to Chiron.. which file do i need to get the position for it

I am not actually sure — I have generated positions for Jupiter's moons, but not the most outer planets. My approach would be to search the links here:

https://rhodesmill.org/skyfield/planets.html#ephemeris-download-links

— for missions that might include Pluto and Charon.

[tutucea]

got it, thanks for you help and i apologize for bothering you <3

[brandon-rhodes]

Thanks for understanding that I've only used a few NASA .bsp files myself, and that I'm not an expert on where they store all of their planetary data 🙂