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Elegant astronomy for Python
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skyfield won't read part one of DE441 #803

Closed xdw316 closed 1 year ago

xdw316 commented 1 year ago

from skyfield.api import Star, load planets = load('de441.bsp') print(planets) earth = planets['earth'] from skyfield.api import T0

ts = load.timescale() t = ts.utc(-4000, 1, 1)

arcturus = Star(ra_hours=(14, 15, 39.67207), dec_degrees=(19, 10, 56.6730), ra_mas_per_year=-1093.39, dec_mas_per_year=-2000.06, parallax_mas=88.83, radial_km_per_s=-5.229)

print('astrometric') astrometric = earth.at(t).observe(arcturus) ra, dec, distance = astrometric.radec() print(ra) print(dec)

Python 3.7.3 (v3.7.3:ef4ec6ed12, Mar 25 2019, 22:22:05) [MSC v.1916 64 bit (AMD64)] on win32 Type "help", "copyright", "credits" or "license()" for more information.

RESTART: C:/Users/Emily/AppData/Local/Programs/Python/Python37/Tools/demo/starInput.py SPICE kernel file 'de441.bsp' has 28 segments JD -3100015.50 - JD 2440432.50 (-13200-05-06 through 1969-07-29) 2 -> 299 VENUS BARYCENTER -> VENUS 1 -> 199 MERCURY BARYCENTER -> MERCURY 3 -> 399 EARTH BARYCENTER -> EARTH 3 -> 301 EARTH BARYCENTER -> MOON 0 -> 10 SOLAR SYSTEM BARYCENTER -> SUN 0 -> 9 SOLAR SYSTEM BARYCENTER -> PLUTO BARYCENTER 0 -> 8 SOLAR SYSTEM BARYCENTER -> NEPTUNE BARYCENTER 0 -> 7 SOLAR SYSTEM BARYCENTER -> URANUS BARYCENTER 0 -> 6 SOLAR SYSTEM BARYCENTER -> SATURN BARYCENTER 0 -> 5 SOLAR SYSTEM BARYCENTER -> JUPITER BARYCENTER 0 -> 4 SOLAR SYSTEM BARYCENTER -> MARS BARYCENTER 0 -> 3 SOLAR SYSTEM BARYCENTER -> EARTH BARYCENTER 0 -> 2 SOLAR SYSTEM BARYCENTER -> VENUS BARYCENTER 0 -> 1 SOLAR SYSTEM BARYCENTER -> MERCURY BARYCENTER JD 2440432.50 - JD 8000016.50 (1969-07-29 through 17191-03-14) 2 -> 299 VENUS BARYCENTER -> VENUS 1 -> 199 MERCURY BARYCENTER -> MERCURY 3 -> 399 EARTH BARYCENTER -> EARTH 3 -> 301 EARTH BARYCENTER -> MOON 0 -> 10 SOLAR SYSTEM BARYCENTER -> SUN 0 -> 9 SOLAR SYSTEM BARYCENTER -> PLUTO BARYCENTER 0 -> 8 SOLAR SYSTEM BARYCENTER -> NEPTUNE BARYCENTER 0 -> 7 SOLAR SYSTEM BARYCENTER -> URANUS BARYCENTER 0 -> 6 SOLAR SYSTEM BARYCENTER -> SATURN BARYCENTER 0 -> 5 SOLAR SYSTEM BARYCENTER -> JUPITER BARYCENTER 0 -> 4 SOLAR SYSTEM BARYCENTER -> MARS BARYCENTER 0 -> 3 SOLAR SYSTEM BARYCENTER -> EARTH BARYCENTER 0 -> 2 SOLAR SYSTEM BARYCENTER -> VENUS BARYCENTER 0 -> 1 SOLAR SYSTEM BARYCENTER -> MERCURY BARYCENTER astrometric Traceback (most recent call last): File "C:/Users/Emily/AppData/Local/Programs/Python/Python37/Tools/demo/starInput.py", line 18, in astrometric = earth.at(t).observe(arcturus) File "C:\Users\Emily\AppData\Local\Programs\Python\Python37\lib\site-packages\skyfield\vectorlib.py", line 92, in at p, v, gcrs_position, message = self._at(t) File "C:\Users\Emily\AppData\Local\Programs\Python\Python37\lib\site-packages\skyfield\vectorlib.py", line 216, in at p2, v2, , message = vf._at(t) File "C:\Users\Emily\AppData\Local\Programs\Python\Python37\lib\site-packages\skyfield\jpllib.py", line 230, in _at raise e skyfield.errors.EphemerisRangeError: ephemeris segment only covers dates 1969-07-29 23:59:18Z through 17191-03-14 23:58:51Z UT

Bernmeister commented 1 year ago

Perhaps #691 might offer insight...

xdw316 commented 1 year ago

Thanks for the pointer! Problem solved. Experienced with NOVAS and SOFA. New to Python. New to Skyfield. New to Github. Need to learn how to search topics. Thanks again.

brandon-rhodes commented 1 year ago

Thanks for pointing out that there was another issue already addressing this, @Bernmeister! To clean up the issues list, I'm going to close this one in favor of #691.

xdw316 commented 1 year ago

Yes.  Good plan. Dave Walden

On Sunday, April 2, 2023 at 07:40:12 AM EDT, Brandon Rhodes ***@***.***> wrote:

Thanks for pointing out that there was another issue already addressing this, @Bernmeister! To clean up the issues list, I'm going to close this one in favor of #691.

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