Compute the position of the source represented by this coordinate object to a new time using the velocities stored in this object and assuming linear space motion (including relativistic corrections). This is sometimes referred to as an “epoch transformation.”

The initial time before the evolution is taken from the obstime attribute of this coordinate. Note that this method currently does not support evolving coordinates where the frame has an obstime frame attribute, so the obstime is only used for storing the before and after times, not actually as an attribute of the frame. Alternatively, if dt is given, an obstime need not be provided at all.

Parameters¶

new_obstime~astropy.time.Time, optional

The time at which to evolve the position to. Requires that the obstime attribute be present on this frame.

dt~astropy.units.Quantity, ~astropy.time.TimeDelta, optional

An amount of time to evolve the position of the source. Cannot be given at the same time as new_obstime.

Returns¶

new_coord|SkyCoord|

A new coordinate object with the evolved location of this coordinate at the new time. obstime will be set on this object to the new time only if self also has obstime.