RBSE+2009+1

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**---A Summary of--- ** **Developing a High Quality Color Magnitude Diagram for Estimating ** **the Distance to NGC 6694 ** Andrew Hellmund, Elizabeth Mealey, Josiah Smith Hartsbrook High School, Hadley, MA  //Teacher: Charles Weems, ARBSE 2008 // P.4~11 Using V and B-V values for a greater number of stars produces a higher quality color magnitude diagram for an open star cluster. This will help make a more accurate measurement of distance.    
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 * <span style="font-family: "TimesNewRomanPSMT","serif"; font-size: 12pt;">Specific goal: **<span style="font-family: "TimesNewRomanPSMT","serif"; font-size: 12pt;"> The scientific goal of this project was to determine the distance to NGC 6694 (M26) with greater confidence than previous studies using **color-magnitude diagrams (CMD).**
 * <span style="font-family: "TimesNewRomanPSMT","serif"; font-size: 12pt;">What they are going to do: **<span style="font-family: "TimesNewRomanPSMT","serif"; font-size: 12pt;"> Use the images taken through Johnson B and V filters, of an open star cluster to create a CMD that plots B magnitude in relation to B-V. Then it is compared to a standard **Hertzsprung-Russell (H-R)** **Zero Age Main Sequence (ZAMS)** diagram. After aligning the two diagrams, the “shift of the alignment” will give an absolute redshift value.
 * <span style="font-family: "TimesNewRomanPSMT","serif"; font-size: 12pt;">What they did to create the CMD: **<span style="font-family: "TimesNewRomanPSMT","serif"; font-size: 12pt;">The B and V images were analyzed in **ImageJ:** an image analysis program with an astronomy plug-in. The images then were adjusted until the stars were both distinct and bright and was divided into 256 squares (16 X 16) that averaged 7 stars per square. Lastly the data was recorded and imported into a photometric spreadsheet.