WHAT IS THIS? This is your data. Observations of variable stars are commonly plotted on a graph called a light curve, as the apparent brightness (magnitude) versus time, usually in Julian Date (JD). The magnitude scale is plotted so that brightness increases as you go from bottom to top on the Y-axis and the JD increases as you go from left to right on the X- axis. The Light Curve Generator is an online tool for performing just this function. Since its creation in May of 1999 the AAVSO Light Curve Generator has been one of the most popular tools on the AAVSO web site. As of 08/01/2010, over a half a million individual light curves have been plotted. WHAT CAN I DO? First, you must choose the star and time period for which you would like a light curve. The star can be in either Harvard Designation, AUID or based on a name accepted by VSX . The date can be either in JD or mm/dd/yyyy. Next, you need to decide what data you want to display. You can choose to ignore fainter thans and other bandpasses to give a cleaner plot. To some people, presentation is equally as important as what data you analyze. For them we have the ability to customize how you would like your plots to look. By far the most popular feature of the program is the ability to highlight your own observations. HOW CAN I GET HELP? aavso@aavso.org We have a couple of good help guides available for the Light Curve Generator. First, a description of what a light curve is. The Variable Star Astronomy curriculum also has a chapter on light curve analysis. If you need further assistance, send us an E-mail at:

WHAT IS THE NAME, DESIGNATION, OR AUID OF THE OBJECT? DO YOU WANT TO LIMIT THE NUMBER OF DAYS PLOTTED?

If so, enter the number of days to look back from today Days OR, DO YOU WANT TO PLOT A SPECIFIC DATE RANGE?

If so, enter start and end dates here (JD or MM/DD/YYYY) START DATE END DATE ( Click For Current Date WOULD YOU LIKE TO HIGHLIGHT A PARTICULAR OBSERVER?

If so, enter an observer code here WHAT TYPE OF MARK SHOULD BE USED FOR HIGHLIGHTING? Crosshair Box WHICH TYPES DATA WOULD YOU LIKE TO HAVE PLOTTED? Visual R Differential and Step U I Fainter than B J Discrepant V H Tri-R Tri-G Tri-B Unknown Unfiltered w/V zero pt Unfiltered w/R zero pt WHAT DATE FORMAT WOULD YOU LIKE? Calendar JD SHOULD THE PLOT INCLUDE A LIST OF OBSERVERS? Yes No SHOULD A BACKGROUND GRID BE DISPLAYED? Yes No PLOT X-AXIS TICS

Number of days between each X-axis tic WHAT SHOULD THE SIZE OF THE PLOTTED POINTS BE?

Enter a pixel width WHAT SHOULD THE DIMENSIONS OF THE CHART BE?

Enter dimensions in pixels WIDTH HEIGHT WOULD YOU LIKE TO ENFORCE A MAGNITUDE RANGE?

Force the vertical axis to this magnitude range MINIMUM MAXIMUM WOULD YOU LIKE ANY MEAN CURVES PLOTTED?

Enter number of day bins for either/both bands (only works w/JD dates) Days VISUAL BAND Days V-BAND