Barycentric Velocity correction at 1 cm/s level
# barycorrpy Version 0.1 UNDER TESTING
Barycorrpy is the Python version of Jason Eastman and Jason Wright’s IDL code [BaryCorr](http://astroutils.astronomy.ohio-state.edu/exofast/pro/exofast/bary/zbarycorr.pro) based on [Wright and Eastman (2014)](https://arxiv.org/pdf/1409.4774.pdf) . BCPy can be used to calculate the barycentric velocity correction for a star with an accuracy of ~ 1 cm/s . To do this, it takes into consideration the following -
- Revolution of the Earth to consider position and velocity of the Geo-Center (GC) wrt Solar System Barycenter (SSB)
- Rotation of the Earth
- Precession, Nutation and Polar motion of the Earth, along with 2. to calculate the position and velocity of the observatory wrt the Geo-Center.
- Gravitational Time dilation due to objects of the Solar System
- Leap Second offset between UTC and TAI time standards
- Proper motion and systemic radial velocity of the star
- Parallax correction
- Shapiro delay
The installation instructions and the guide on how to run and use the code are explained in the [Wiki](https://github.com/shbhuk/barycorrpy/wiki).
### Leap Second Management
When converting UTC to TDB ([different time standards explained](http://www.cv.nrao.edu/~rfisher/Ephemerides/times.html#TDB)), 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.
### INSTALLATION INSTRUCTIONS
The instructions for installation and getting started for this package are detailed in the [Wiki](https://github.com/shbhuk/barycorrpy/wiki).