lightcurvex

Tool used to extract light curves from CASU VVVX data.

Status: In development

How to extract light curves using this code?

First you need to retrieve the data from the CASU repository, then convert the fits tables to ascii using the provided script, and finally run the python main.py to extract the light curves.

Results are saved inside the DATA_PATH directory.

Updates

04/10/2022 - Simple processing of the data working ok. It produces plots and save each lc individualy.
12/10/2022 - LC are phase folded and obtained from the no tiled data.

Appendix

Instructions for getting the data from the repository

query:

search: 198.B-2004
additional sql: obj like '%411'

Notice that the database schema (column names) can be found here: http://casu.ast.cam.ac.uk/vistasp/imgquery/schema

Instruction to download the fits tables

wget --http-user=username --http-passwd=password \
        http://casu.ast.cam.ac.uk/~eglez/vistasp/requests/XXXXXXXXXXX/filelist
wget --http-user=username --http-passwd=password \
       -m -B http://casu.ast.cam.ac.uk/~eglez/vistasp/requests/XXXXXXXXXXX/ -i filelist

Instructions for converting the fits tables to ascii

Use the provided fortan code to convert the fits tables to ascii. The code is in the assests/ folder. The code is compiled with gfortran. To compile use the following command:

gfortran fitsio_cat_list.f -o fitsio_cat_list -L/sw/lib -lcfitsio -lm

It requires the cfitsio library. To install it, in ubuntu I run the command sudo apt install libcfitsio-bin libcfitsio-dev libcfitsio-doc libcfitsio9.

The script convert_tables.sh can be used to convert all the tables in the current folder. It requires the fitsio_cat_list executable to be in the same folder.

I put the executable in my $HOME/bin folder and added that folder to my $PATH variable. I also added the following line to my .bashrc file:

export PATH=$HOME/bin:$PATH

The columns of the output file are: RA and Dec coordiantes, x, y, magnitude, magnitude error, chip number, stellar classification, ellipticity and position angle.