Stage 02

Summary

  • Navigate to the run directory and execute the pacman_script.py file using the –s02 flag

  • Continue with s03

This stage performs a barycentric correction because the time stamps for the observations do not account for HST’s orbital motion.

Successfully reloaded meta file
Starting s02
Converting MJD to BJD: 100%|##########| 2/2 [00:02<00:00,  1.35it/s]
Writing t_bjd into filelist.txt
Saving Metadata
Finished s02

After the calculation has been performed, the user can check a newly generated plot also saved into “ancil/horizons”. Here we show the plot generated for the first of the two visits:

_images/bjdcorr_horizons_results_v0.png

The axis are the distance of HST to the Solar System Barycenter in kilometers. Horizons start and Horizons end show where our Horizon file starts and ends containing X,Y,Z information. The black crosses in the plot show the times when HST actually observed. One can see that HST observed 4 orbits in this particular visit (which agrees with the filetable.txt from Stage 00). One can also see the colored curve is a bit wiggley. This is in fact the rotation of HST around the earth. The colored curve consists of a lot of points. Each one is an X,Y,Z position of HST downloaded from HORIZONS. The color coding denotes the time direction.

The filetable.txt is updated in this stage and contains a new column called t_bjd with the time of observations in BJD. E.g. (only showing the first few lines):

================== ===== ====== ====== ======== ================== ================== ================== ==== ========== ==================
         filenames instr ivisit iorbit iexp_orb              t_mjd            t_visit            t_orbit scan        exp              t_bjd
================== ===== ====== ====== ======== ================== ================== ================== ==== ========== ==================
ibxy07p9q_ima.fits F130N      0      0       -1     56364.52973075                0.0                0.0   -1   0.833445  2456365.030605767
ibxy07paq_ima.fits  G141      0      0        0 56364.531017044996 1.8524696677923203 1.8524696677923203    0 103.128586  2456365.031892204
ibxy07pbq_ima.fits  G141      0      0        1 56364.532660565004  4.219395741820335  4.219395741820335    1 103.128586  2456365.033535903
ibxy07pcq_ima.fits  G141      0      0        2    56364.534304085  6.586317792534828  6.586317792534828    0 103.128586 2456365.0351795987
ibxy07pdq_ima.fits  G141      0      0        3      56364.5359476  8.953226432204247  8.953226432204247    1 103.128586 2456365.0368232853
ibxy07pfq_ima.fits  G141      0      0        4 56364.537591119995 11.320137083530426 11.320137083530426    0 103.128586  2456365.038466973