This document assumes you have saved the light curve generated with the Large Ensemble Photometry application as a CSV file, as described in Part 3.

In this example, we determine the period of the variable star SZ Lyn using the VSTAR application.

Install VSTAR

Download and install VSTAR from:

https://www.aavso.org/vstar

Prepare the CSV File

Open the CSV file generated in Part 2 and delete all columns except:

  • JD
  • Target Mag

Save the file again as a CSV containing only these two columns.

Load the Data into VSTAR

Load the CSV file into VSTAR.

Light curve loaded into VSTAR

Perform a Fourier Analysis

  1. Click:
Analysis → DC DFT standard scan

This produces a Data Compensated Discrete Fourier Transform (DC DFT) of the light curve.

Because the example series does not have a name, it is labeled as unspecified.

Selecting the data series

DC DFT power spectrum

Determine the Candidate Frequency

Click on the highest (red) data point in the power spectrum to obtain the candidate frequency.

In this example, the candidate frequency is:

8.28 cycles/day

The corresponding period is:

Period = 1 day / 8.28
       = 0.1208 days
       = 2.899 hours

Conclusion

The Fourier analysis performed by VSTAR yields a candidate period of:

Period ≈ 2.899 hours

This value is in excellent agreement with the period determined previously using LEPhot, confirming that SZ Lyn has a period of approximately 2.89 hours.