Apply proper motion

PyAstronomy.pyasl.applyProperMotion(ra, dec, pmra, pmdec, dt, fixes=1)

Apply proper motion to coordinates

Parameters

ra, decfloat or array

Coordinates at reference epoch

pmra, pmdecfloat or array

Proper motion in mas/yr.

dtfloat

Elapsed time [yr]

fixesint, optional

Number of steps in which the proper motion is applied. Default is one.

Example: Proper motion of GJ 1215

from __future__ import print_function, division
from PyAstronomy import pyasl

# Year 2018 coordinates and proper motion (mas/yr)
# of GJ 1215
ra, dec = 259.4319131981014, +11.6678903453170
pmra, pmdec = -352.897, -445.558

# Calculate 2050 position
ra5, dec5 = pyasl.applyProperMotion(ra, dec, pmra, pmdec, dt=2050-2018, fixes=1)

print("Position 2018: %10.6f  % 10.6f" % (ra, dec))
print("Position 2050: %10.6f  % 10.6f" % (ra5, dec5))