Version 0.1
Barycorrpy is the Python version of Jason Eastman and Jason Wright's IDL code BaryCorr based on Wright and Eastman (2014). BCPy can be used to calculate the barycentric velocity correction for a star with an accuracy well below 1 cm/s . To do this, it takes into consideration the following effects-
- Revolution of the Earth to consider position and velocity of the geocenter with respect to the Solar System barycenter
- Rotation of the Earth
- Precession, nutation and polar motion of the Earth, along with the above to calculate the position and velocity of the observatory with respect to the geocenter
- Gravitational time dilation due to objects of the Solar System
- Leap second offset
- Proper motion and systemic radial velocity of the star
- Parallax
- Shapiro delay
The installation instructions and the guide on how to run and use the code are explained in the wiki.
When converting UTC to TDB (different time standards explained), we need to inlcude for the leap second correction.
We do not use Astropy for this correction due to the lack of an efficient mechanism to update the files when a new leap second is announced. Leap seconds are hard coded into Astropy's ERFA routines, and thus to update for a new leap second the user would have to update Astropy and re-compile it.
In this routine utc_tdb.py, we incorporate this is a stand alone file which is checked every time the code is run. Details for this can be found in the wiki.
The instructions for installation and getting started for this package are detailed in the wiki.