Astro-Tools

Collection of utility scripts made during my master's thesis at the UANL.

Eclipsing binary q-search (q-search.py)

Run a q-search algorithm for a given contact binary system using PHOEBE. Tests a grid of q values, finding the best fit by adjusting the system's parameters (incl@binary, fillout_factor, and teffratio for contact binaries; incl@binary, teffratio, requivsumfrac, esinw, and ecosw for (semi-)detached systems) using a Nelder-Mead Simplex optimizer. Outputs all individual solutions obtained from the optimization along with their corresponding q value and $\chi^2$ score as a comment in each solution.

Alternatively, this solver can be configured to test only specific orbital inclination values, treating it as a fixed parameter and finding the corresponding solutions to the given q grid.

For usage information see:

python q-search.py --help

Requirements

• python>=3 (tested as is with Python 3.12.2)
• phoebe
• tqdm

Align FITS images (align-images.py)

Aligns scientific FITS images such that targets overlap in pixel-space. Uses the FITS World Coordinate System (WCS) to project all images in a single directory onto the first image encountered. This facilitates aperture photometry using tools (eg. IRAF) that rely on pixel coordinates.

This script makes the following assumptions:

• All of the FITS images in the directory can be projected onto each other. I used this on a per-night basis, never mixing across multiple nights of observations.
• If an image cannot be plate-solved it must be unusable and not included in the final results.
• No calibration (bias, dark, or flat) is applied at any stage in the process.

Requirements:

• python>=3 (tested as is with Python 3.12.2)
• tqdm

Astrometry

This script also makes use of Astrometry for the plate-solve routine. In particular you must install the solve-field command from the astrometry package.

Ubuntu:

sudo apt install astrometry

Fedora:

sudo dnf install astrometry

In order to plate-solve the fields obtained with the 0.5m CDK telescope at the Observatorio Astronómico Universitario - Iturbide I needed a total of ~10GB for the required data files. These can be downloaded using the download-astrometry-data.sh script, which will place these data files in the proper directory for solve-field to find.