search

brandon-rhodes / pyephem

Scientific-grade astronomy routines for Python
Other
772 stars 121 forks source link

How to calculate equitoral declanation for moon #238

Open manujchandra opened 2 years ago

manujchandra commented 2 years ago

Hi,

I have a book. Its written that on 26 Jan 2018 at 12:00 pm Geocentric the declination of moon was 58.55 degrees. right ascension was 15.06

But when I am computing I am getting 55 degree. Surely I am making a mistake:

import ephem
import numpy as np

moon = ephem.Moon()

NYC = ephem.Observer()
# https://www.latlong.net/place/new-york-city-ny-usa-1848.html
NYC.lat = '40.730610'
NYC.lon = '-73.935242'
NYC.elevation = 21.95
NYC.date = '2018/1/26 12:00'

moon.compute(NYC)

# Geocentric
np.degrees(moon.ra)
55.53394490697903

Similarly for 5 Feb 2019 it was 330.18 [-14.99] but I am getting 326

Please help me to match the values. Thanks.

brandon-rhodes commented 2 years ago

It will help if we can check whether the book is using a different frame of reference or timescale, so: what is the name and publication date of the book?