Part I. Introduction
This document describes how to access a revised set of signal definitions and associated TTVs for mission based and community based signals collectively referred to as POIs (Planetary Objects of Interest). POIs include TOIs, CTOIs, K2OIs, and KOIs.
A signal definition specifies the reference epoch, signal duration, and transit period for a POI signal. From the first and third property, the calculated time for each transit of a signal in a light curve can be determined. Due to other orbiting bodies in a star system or to an inaccurate signal definition, the calculated time and observed time of a transit may not align. A TTV (transit timing variation) indicates the time difference between the observed time and calculated time of a transit in a light curve.
The revised dataset provides much greater accuracy in transit times and durations as compared to the default dataset supplied by LcTools. As a result, color-coded POI signals are more accurately displayed in a light curve.
The revised dataset is split into two tables as shown below. The first table applies to libraries and the second applies to catalogs. Note that columns "Signals Recorded", "TTVs Recorded", "Last Time Series Period", and "Created On" applies to both tables.
Libraries contain signal files and TTV files that are automatically imported by LcViewer and LcSignalFinder when a light curve file is loaded. See Part II below for setting up revised libraries in LcTools. Catalogs are CSV files containing signal definitions and TTVs for a POI type and are intended for use outside the LcTools system.
Table 1. Revised Libraries for Use in LcTools
Mission: TESS, K2, or Kepler.
POI Type: TOI, CTOI, K2OI, or KOI.
Signal Library: A data directory containing one signal file for each star. A signal file contains the revised signal definition for each POI in the star system.
TTV Library: A data directory containing one TTV file for each POI signal in the star system. A TTV file contains the revised calculated and observed time for each transit of the signal.
Signals Recorded: The number of POI signals that are recorded in the signal library and catalog.
TTVs Recorded: The number of TTVs that are recorded in the TTV library and catalog.
Last Time Series Period: The last sector, campaign, or quarter analyzed in the light curves. Applies to libraries and catalogs. TESS light curves may have time series from four different projects -- TESS, TESS_SPOC, TESS_QLP, and TESS_ELEANOR. As such, the last period from each project is shown separated by a "/". For eample, "77/69/74/10".
Created On: The date in which the libraries and catalogs were created.
Table 2. Revised Catalogs for External Use
Mission: TESS, K2, or Kepler.
POI Type: TOI, CTOI, K2OI, or KOI.
Signal Catalog: A CSV file containing the revised signal definitions for the POI type.
TTV Catalog: A CSV file containing the revised TTVs for the POI type. Each TTV contains the calculated and observed time for a transit.
TTV Summary Report: A CSV file containing the number of TTVs, median TTV magnitude in hours, and maximum TTV magnitude in hours for each POI signal in the catalog.
Part II. Setting Up Revised Libraries in LcTools
Use of revised libraries in LcTools is optional. LcTools provides default libraries that may be adequate for your needs. If you require greater accuracy for transit times and durations, consider switching from the default libraries to the revised libraries.
To set up the revised libraries for a POI type, follow the procedures below.
Downloading & Installing a Revised Signal Library
Using Table 1 above, click on the revised Signal Library you wish to access. You will be taken to Google Drive on the Web.
Click the Download icon located in the top right corner of the web page. After file is downloaded, click on the ZIP file to open it.
If an old revised signal library exists on your computer, delete it.
Extract (unzip) the signal library folder to a target drive. For example, "C:\".
Close the ZIP file.
Downloading & Installing a Revised TTV Library
Using Table 1 above, click on the associated TTV Library for the revised signal library you installed. You will be taken to Google Drive on the Web.
Click the Download icon located in the top right corner of the web page. After file is downloaded, click on the ZIP file to open it.
If an old revised TTV library exists on your computer, delete it.
Extract (unzip) the TTV library folder to a target drive. For example, "C:\".
Close the ZIP file.
Switching From the Default Libraries to the Revised Libraries in LcViewer
Start LcViewer. If the "Open Lightcurve" dialog box is displayed, click Cancel.
Select "File->Setup Signal Libraries" from the menu bar. The "Setup Signal Libraries" dialog box will open.
Select the Mission for the revised signal library per Table 1 above.
Click Add. The "Add Existing Signal Library" dialog box will open. Click Browse, navigate to the revised signal library that you installed previously, select the signal library folder, click "Select Folder" then click OK. The revised signal library will be added to the bottom of the list box.
Single-click the revised signal library to highlight it (all the other signal libraries will be deselected). Then repeatedly click the Up button to move the revised signal library to the top of the list box giving it the highest precedence.
Using Ctrl+M1, select the signal libraries in the list that you wish to use EXCLUDING the default signal library below:
If POI Type Is Exclude Default Signal Library
TOI TOIs
CTOI CTOIs
K2OI K2OIs
KOI KOIs
Confirm that the revised signal library is selected and the default signal library is deselected.
Click OK to close the "Setup Signal Libraries" dialog box. On the confirmation message box, click Yes.
Select "File->Setup TTV Libraries" from the menu bar. The "Setup TTV Libraries" dialog box will open.
Select the Mission for the revised TTV library per Table 1 above.
Click Add. The "Add Existing TTV Library" dialog box will open. Click Browse, navigate to the revised TTV library that you installed previously, select the TTV library folder, click "Select Folder" then click OK. The revised TTV library will be added to the bottom of the list box.
Single-click the revised TTV library to highlight it (all the other TTV libraries will be deselected). Then repeatedly click the Up button to move the revised TTV library to the top of the list box giving it the highest precedence.
Using Ctrl+M1, select the TTV libraries in the list that you wish to use EXCLUDING the default TTV library below:
If POI Type Is Exclude Default TTV Library
TOI TOI_TTVs
CTOI CTOI_TTVs
K2OI K2OI_TTVs
KOI KOI_TTVs
Confirm that the revised TTV library is selected and the default TTV library is deselected.
Click OK to close the "Setup TTV Libraries" dialog box. On the confirmation message box, click Yes.
Exit LcViewer.
Switching Libraries in LcSignalFinder
Start LcSignalFinder.
Execute steps 12 through 25 above in LcSignalFinder.
Exit LcSignalFinder.