QuarkNet+2007

Summer 2007
 * Notre Dame QuarkNet Center**

McNeely, Ribaudo, et.al.
 * SZ Herculis: An Eclipsing Binary **

We are presenting results from observing sessions of the eclipsing binary star system SZ Herculis (SZ Her), taken from eclipses that occurred on July 12 and July 25, 2007. We observed eclipses visually and with various instruments and telescopes. Eclipses of SZ Her last approximately 180 minutes, and we determined that the star achieved a minimum magnitude of 11.8 at greatest eclipse. We also determined the universal time of each minima.
 * Abstract **

The July 12 eclipse was observed using a Celestron CPC, an 8-inch Schmidt-Cassegrain telescope.Measurements were estimated visually by comparing SZ Her with companion stars of constant magnitude located within the same field of view. The July 25 eclipse was observed locally using a single-cell photometer (Optec model SSP-3) and remotely using a 14-inch Celestron telescope located at the New Mexico Skies Observatory (NMSO), Cloudcroft NM. The 14-inch Celestron was equipped with an SBIG ST-10XE CCD camera. The telescope was operated via the Internet, and data was downloaded the next day.
 * Equipment **


 * [[image:Picture2_small.jpg]] ||  || [[image:Picture1_small.jpg]] ||

Calculation of the magnitude of SZ Her required comparison to a star of constant brightness. The fluxes of SZ Her and its comparison star were read from the photometer’s output and converted to apparent magnitude using the below equation.
 * Analysis **


 * Summary **

On July 12, 2007, using visual methods, we determined that the binary star SZ Her reached greatest eclipse at 531 UT and achieved a minimum apparent magnitude 11.8. On July 25, 2007, using a remote CCD camera, we observed SZ Her reach a minimum apparent magnitude of 11.8 at 545 UT. On this evening we also measured the eclipse using the Optec photometer but, due to intermittent clouds, were only able to obtain scattered data points. We plan to submit our data to the AAVSO for potential inclusion within their SZ Her database.