AAVSO Historical Light Curves

Below are 25 sample data entries that were collected by the AAVSO for the variable star SS Cygni. The first column is the designation (the year 1900 epoch right ascension and declination) of the star; the second column is the name of the star; the third column is the Julian Date and decimal of day (date and time) of the observation; the fourth column is the magnitude estimate of the variable; and last are the observer initials of the observer who made the observation.

The first entry here for the star SS Cygni shows that at 16:19 UT on January 1, 2000 the observer with initials MOK recorded the magnitude of SS Cygni to be 9.2. The last entry shows that at 23:40 UT on January 3, 2000 the observer with initials BVE observed SS Cygni at 10.4 magnitude. Data points such as these, submitted by observers from around the world, are what make up the long-term light curve of SS Cygni at the bottom of the page.

The AAVSO International Database contains a lot more than just two days worth of data for SS Cygni. Below is the long-term light curve of SS Cygni which spans the time from 1895 to the present and incorporates all of the AAVSO data for this star. Also presented is the historical light curve of RS Ophiuchi which is another star in the AAVSO visual observing program. These are representative curves and should not be used for official research purposes, as they may not have passed the strict quality controls of the AAVSO.

Official AAVSO data may be obtained from the AAVSO website on the Data Request page or contact the AAVSO. We will be glad to help you out by providing the highest quality data available.