1 Searching for TOI 175 candidates

TOI-175 is a system composed of at least four planets: three of them are transiting their stellar disk (Kostov et al. ,2019) and one additional non-transiting planet was detected from Radial Velocities (RV) measurements (Demangeon et al. ,2021). A search on this system is a good exercise to test the SHERLOCK capabilities: from the search execution to the vetting of a signal. In this example we will execute the SHERLOCK search and in the next ones we will vet and validate the found signals.

We will use the properties file named search.yaml under the same directory than this notebook.

import os
your_execution_dir = os.getcwd()
with open(your_execution_dir + '/search.yaml', 'r') as f:
    print(f.read())

TARGETS:
  TIC 307210830: #TOI 175
    INITIAL_HIGH_RMS_MASK: False
    INITIAL_SMOOTH_ENABLED: True
    PERIOD_MIN: 0.4
    PERIOD_MAX: 150 
    SECTORS: all
    EXPTIME: 120
    OVERSAMPLING: 3
    CPU_CORES: 7
    DETREND_METHOD: 'biweight'
    DETRENDS_NUMBER: 10
    DETREND_CORES: 10
    MAX_RUNS: 10

Search execution

We would now have to run sherlock by running it with a python one-liner. Please take into account that this search takes a lot of computational power and time. Hence, we will run this command in a server and will prompt the output in the notebook instead of executing it here:

python3.8 -m sherlockpipe --properties search.yaml

The execution will create a resulting directory named /TIC307210830_all. For this notebook we packed all the directories within the TOI-175-results directory. Ok, lets inspect the candidates found by sherlock:

with open(your_execution_dir + '/TOI-175-results/TIC307210830_all/TIC307210830_all_candidates.log', 'r') as f:
    print(f.read())

Listing most promising candidates for ID TIC307210830_all:
Detrend no. Period    Per_err   Duration  T0      Depth   SNR     SDE     FAP       Border_score  Matching OI   Harmonic    Planet radius (R_Earth)  Rp/Rs     Semi-major axis   Habitability Zone   
4           3.6907    0.00020   55.41     1356.20 1.686   215.95  191.11  0.000080  0.98          TOI 175.01    -           1.40868                  0.03683   0.03110           I                   
9           2.2531    0.00012   44.83     1354.90 0.627   95.93   123.06  0.000080  0.99          TOI 175.03    -           0.85893                  0.02241   0.02238           I                   
3           7.4507    0.00059   68.70     1355.29 0.876   95.88   130.23  0.000080  1.00          TOI 175.02    2*SOI1      1.01554                  0.02454   0.04967           I                   
4           1.0492    0.00006   53.67     1354.72 0.158   40.95   152.97  0.000080  0.99          nan           -           0.43172                  0.01205   0.01344           I                   

It seems that sherlock has spotted the first known transiting planets easily. There is an additional fourth signal in the fourth run. Lets take a look into the selected signal of that run (you can see the Detrend no. column, with a 4 as value).

file_image = your_execution_dir + '/TOI-175-results/TIC307210830_all/4/Run_4_ws=0.6242_TIC307210830_all.png'
from IPython.display import Image
Image(filename=file_image)

Well, that seems like a really promising candidate! Let’s go to the next section to create a vetting report to assess its quality!