1. Global Hands-On Universe meeting July 15, 2007 Authentic Data in the Classroom with the Sloan Digital Sky Survey Jordan Raddick (Johns Hopkins University)

2. Jordan Raddick The Sloan Digital Sky Survey Map of the universe 2.5 m telescope in New Mexico CCD imaging Follow-up spectra

3. Jordan Raddick The Data of the SDSS Photometric Data Spectral Data

4. Jordan Raddick Photometric Data Tri-color images Single-color FITS files –ultraviolet (u) –green (g) –red (r) –infrared (i, z) Magnitudes through each filter Object type More…

5. Jordan Raddick Spectral Data 3800 to 9200 Ångstroms GIF files with prominent lines marked FITS files available –SpecView Java applet (STScI) Object type and redshift Detailed line widths and strengths

6. Jordan Raddick Introduction to DR6 ~9,600 square degrees –(Full moon is 0.25 square degrees) Images of ~280 million objects –~90 million stars, ~140 million galaxies ~1 million spectra –~60,000 stars, 600,000 galaxies, 75,000 quasars Science quality data Where in the sky?

7. Jordan Raddick DR6 Photometric Coverage (Both areas, Aitoff projection of equitorial coordinates)

8. Jordan Raddick DR6 Spectral Coverage (Both areas, Aitoff projection of equitorial coordinates)

9. Jordan Raddick SkyServer web site Entire dataset from the SDSS Research-grade science data and tools Promotes use of real science data in education

10. Jordan Raddick Example: H-R Diagram Strategy: –Get data for a lot of stars in a star cluster –Need magnitudes –Plot color vs. magnitude –Interpret Palomar 5 –RA = 229.013, Dec = -0.123, Radius = 3 arcmin

11. Jordan Raddick Get Data Search Form Tools -> Search -> Search Form Form is a sentence where you fill in words Show me stars at RA = 229.013, dec = -0.1083, radius = 3. Show me 1,000. Get object ID, RA, Dec, and magnitudes. Click Generate Query

12. Jordan Raddick Get Data Your request is translated into SQL code: select top 1000 p.objid, p.ra, p.dec, p.u, p.g, p.r, p.i, p.z from star p Switch Output Format to CSV Click Submit Query to SkyServer or Submit Query to Image List Download or save file

13. Jordan Raddick View and Analyze Data Open CSV file in a graphing program Note bug with Object IDs Add new columns for u-g, g-r, r-i, i-z

14. Jordan Raddick Plot Data

15. Jordan Raddick Interpret Plot Interpret plot to learn stellar evolution See SkyServers Project on H-R Diagram Projects -> Advanced -> H-R Diagram

16. Jordan Raddick Galaxy Zoo New project Classify galaxies as spiral or elliptical Participate in meaningful scientific project