4 Validation of TOI 1798.01

TOI 1798.01 has already passed the vetting checks. Its depth is of 800 ppts, which is very shallow for our available observatory TRAPPIST-North. So, given that we can’t trigger a quick ground-based follow-up we will try to validate the candidate. There are contrast curves available in ExoFop taken by the 8m Gemini Observatory. We will use one of them (562 nm) to improve the validation convergence and precision. Hence, we will run:

python3.8 -m sherlockpipe.validate --candidate 1 --contrast_curve TOI1798I-ef20200606-562_sensitivity.csv

The output of the validation generated by sherlock consists on one PDF report and a few csvs stored for reproducibility. In order to explore the resulting PDF page by page in this notebook we will need the pdf2image module.

! python3.8 -m pip install pdf2image

Defaulting to user installation because normal site-packages is not writeable
Requirement already satisfied: pdf2image in /home/martin/.local/lib/python3.8/site-packages (1.16.2)
Requirement already satisfied: pillow in /home/martin/.local/lib/python3.8/site-packages (from pdf2image) (8.1.0)

[notice] A new release of pip available: 22.3.1 -> 23.0
[notice] To update, run: python3.8 -m pip install --upgrade pip

Now that it is installed, let’s begin with the report. We will load the summary PDF and convert it into a set of images (one image per page).

from pdf2image import convert_from_path
from IPython.display import Image
import os 

your_execution_dir = os.getcwd() 
# Store Pdf with convert_from_path function
images = convert_from_path(your_execution_dir + '/TIC198153540_[16,_22,_23,_49,_50]/validation_0/triceratops/TIC 198153540_statistical_validation_report.pdf')

Time to look into the first page. Table 1 and 2 are self descriptive, giving information about the target star and the planet candidate. Figure 1 shows the focused folded curve of the transit with 100 bins:

images[0]

In the second page we will find the Figure 2, showing the contrast curve that we injected to the validation engine. In addition, the Figure 3 shows the field of view of the target and its closest neighbours:

images[1]

Starting in the page 2 and ending in the page 3, we find the Table 3, that contains all the scenarios that TRICERATOPS took into account for the computation with their converged orbital parameters and normalized probabilities (sum = 1). Also in the page 3, we find the Table 4. This is the most important table of this report and shows all the scenarios False Positive Probabilities (FPP) and Nearby False Positive Probabilities (NFPP), together to the boosted FPPs contemplating the Lissauer et al. (2012) boost, in case you decided to take into account. Right next to the Table 4, the Figure 4 plots the FPP/NFPP map with the Nearby False Positive and Likely Planet thresholds.

images[2]

With the vetting passed and the information extracted from the validation we can ensure that this candidate is very strong, and could also be considered as a confirmed planet given that its NFPP is below 1e-3 and the FPP is below 1.5e-2.