Barycentric Velocity Correction (beta)

This online applet runs barycorr from Wright & Eastman (2014) which calculates the barycentric velocity correction for each UTC with a maximum error of 2.4 mm/s, compared to TEMPO2 (See Figures 2 and 3). Mouse over the inputs for an explanation and the required precision of inputs for desired precision of output. For 3 m/s precision, all optional fields can be ignored.

For m/s precision, one should calculate the barycentric correction throughout the exposure and perform a flux and barycentric correction weighted average. This error scales as the square of the exposure time.

There is a programmatic interface to this applet. Here is an example that recreates the values found in Table 2 (Tau Ceti with coordinates in the Hipparcos Epoch), multiplied by c. The optional parameters, if not specified, will default to the values displayed here. You may also set OBSNAME to an allowed string in and RAUNITS to "hours" to signify the input RA is in hours instead of its default of degrees.

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Only required for < 3 m/s precision

-- User inputs are NOT logged

If you have made use of this calculator (or the source code) in a scientific paper, please cite our paper, which contains a more thorough explanation of the various corrections involved in this calculation.

Copyright © Jason Eastman ( All Rights Reserved. Questions, comments, or bug reports welcome.
Last revised: Apr 28, 2016 [jde/cfa]