BASTA-Web

A web interface for the BAyesian STellar Algorithm

BASTA (Bayesian STellar Algorithm) is a Python tool that infers stellar parameters using Bayesian modeling. By fitting any combination of photometric, spectroscopic, and asteroseismic data to large grids of stellar models, it estimates stellar properties such as mass, radius, and age.

Read the documentation

BASTA Data Input

Stellar data

Upload a whitespace-separated ASCII file of stellar parameters for your targets. The first line must be a header starting with #. The first column should contain a unique string ID for each star (starid). For every quantity to be fitted for, provide an uncertainty column with the same name plus _err (e.g. Teff, Teff_err). Column names must match the BASTA parameter list. Use a single, consistent placeholder for missing values (e.g. -999.99).

Coordinate system

If you are fitting for parallax or predicting distance, specify which coordinate system to use and make sure the coordinates are in your uploaded stellar data file.

Coordinates must exist as columns in the uploaded stellar data file if fitting parallax or estimating distance.

Photometric filters

If you are estimating distance, you must provide at least one magnitude and the associated uncertainty. The filter names should match valid entries recognized by BASTA (e.g. Mj_2MASS, Mh_2MASS, Mk_2MASS) and Filters are automatically detected from your input stellar data file. Filters not included in your later-selected stellar model grid will be ignored.

Individual frequencies

If fitting individual mode frequencies or frequency ratios, you must provide a separate ASCII file for each starid in your input list. The name of each file must exactly match the corresponding starid specified in the stellar data file with the extension '.fre' (and include a header starting with #). At a minimum, each frequency file must include the angular degree of each mode (labelled l, ell or degree), the mode frequency (freq or frequency) and uncertainties for the frequencies. These should be provided as either a single column for symmetric uncertainties (err or error), or two columns for asymmetric uncertainties (error_plus and error_minus). Optionally, you may also include the radial order (order or n) if available.

Upload one ASCII file per star (starid.fre), or a .tar.gz archive with one such file per star.