diff --git a/main/astrodatagui/AstrodataGUI.py b/main/astrodatagui/AstrodataGUI.py
index ab16dee..2038677 100644
--- a/main/astrodatagui/AstrodataGUI.py
+++ b/main/astrodatagui/AstrodataGUI.py
@@ -61,6 +61,8 @@ class AstrodataGUI(QtWidgets.QMainWindow):
         self.btCountAllFlares.clicked.connect(self.btCountAllFlaresClicked)
         self.btOpenSavedFlareCountFile.clicked.connect(self.btOpenSavedFlareCountFileClicked)
 
+        self.flaredetectorPreview.periodsCalculated.connect(self.updatePeriods)
+
         self.setupCustomSimbadQueries()
         self.show()
         self.loadDB()
@@ -200,6 +202,9 @@ class AstrodataGUI(QtWidgets.QMainWindow):
         filePath = self.starDB.getFilePath(mainName, source, seq)
         self.flaredetectorPreview.setFitsFile(filePath, mainName)
 
+    def updatePeriods(self, periods: list):
+        self.edPlotFoldPeriod.setText(str(periods[0].value))
+
     def btCombineSeqClicked(self):
         #self.gbPlotOptionsNormalize.setEnabled(False)
         mainName = self.listDownloaded.currentItem().text()
diff --git a/main/astrodatagui/ui/FlaredetectorWidget.py b/main/astrodatagui/ui/FlaredetectorWidget.py
index 789d892..6093a19 100644
--- a/main/astrodatagui/ui/FlaredetectorWidget.py
+++ b/main/astrodatagui/ui/FlaredetectorWidget.py
@@ -1,4 +1,5 @@
 from PyQt5 import QtWidgets
+from PyQt5.QtCore import pyqtSignal
 from matplotlib.figure import Figure
 from matplotlib.backends.backend_qtagg import (
      FigureCanvas, NavigationToolbar2QT as NavigationToolbar)
@@ -13,6 +14,9 @@ from ...flaredetector.util import (findMaxIndices, plotFlarePeaks,
 from ...flaredetector.flaredetector import calculateFlareFitsForLightcurve
 
 class FlaredetectorWidget(QtWidgets.QWidget):
+
+    periodsCalculated = pyqtSignal(list)
+
     def __init__(self, name):
         super(FlaredetectorWidget, self).__init__()
 
@@ -193,7 +197,10 @@ class FlaredetectorWidget(QtWidgets.QWidget):
         lc.flux_err = lc[self.fluxErrType]
         self.currentFlattenLC = lc.flatten(window_length=self.FlattenState["WindowLength"],
                                 polyorder=self.FlattenState["PolynomialOrder"])
+        self.foldedLC = lc.to_periodogram(method=self.PeriodogramState["Method"])
         self.peaks, self.fits = calculateFlareFitsForLightcurve(self.currentFlattenLC, num=100)
+        self.periods = [self.foldedLC.period[i] for i in findMaxIndices(self.foldedLC, num=4, distance=100, sortByHighest=False)]
+        self.periodsCalculated.emit(self.periods)
 
     def updatePlot(self):
         lc = self.currentLC