# Calculate depth and duration of exoplanet's transit using Python, astropy or lightkurve

I am creating a program for the analysis of exoplanets in Python using Astropy and Lightkurve libraries. I have light curve of specified star and I would like to calculate depth and duration of planet transit. There is example for Kepler 10 bellow with these steps:

• Load target pixel image for Kepler 10,
• Convert it to flattened time series,
• Calculate period using periodogram,
• Create folded light curve.
import lightkurve as lk

periodogram = lightcurve.to_periodogram(method="bls", period=np.arange(0.5, 10, 0.001))
period = periodogram.period_at_max_power

folded.scatter()
print(period)


The output is (I marked the depth and duration in red):

Now, how can I calculate duration of transit (approximately from -0.15 to to 0 on x-axis)? Interval from -0.5 to 0.5 should be whole period (0.837 d), so transit duration should be +/- 0.13 d.

min = np.min(folded.flux)
median = np.median(folded.flux)
median / min - 1 # 0.00038


However, the minimum point is not the one in the middle of the transit due to noise, so transit depth may not be accurate.