1. R Ophiuchi, A Mira- Type Variable Star Vikas Agtey Emily Berryman Caroline Fletcher Linda Gong Aaron McNeely Dan Walsh University of Notre Dame QuarkNet Center Summer, 2013 Advisor: Dr. Dan Karmgard

2. Astrophysics Group Projects Major projects: – Variable star photometry – Asteroid astrometry (IASC) – General stargazing, telescope use, astrophotography Outreach: Solar observing for Sensing the Cosmos; Observatory visit for iLED Field Trips: Adler Planetarium, Kalamazoo Air Zoo, Joshua Tree Museum

3. Variable Stars Stars that change brightness over time Project: Measure the brightness (magnitude) of one or more variable stars Collect and submit data to the American Association of Variable Star Observers (AAVSO)AAVSO

4. CCD Photometry Photometry: The measurement of the brightness of stars Use telescope and CCD camera to determine the brightness of variable stars Values estimated in “magnitude”

5. CCD & Telescope Telescope: Celestron CPC 1100, 11-inch Schmidt- Casssegrain reflector, located at Morrison Observatory, Notre Dame CCD: SBIG ST8-XE Software: – CCDSoft: Take and combine images – MaximDL: Photometry tool to measure stellar magnitudes

6. + = Raw images Flat fields Dark fields Image for photometry 

7. Estimating Magnitude For our unknown variable star, we compare its brightness to nearby stars of known magnitude (arrows) contained within the CCD image area Use MaximDL software to perform magnitude measurements Submitted magnitude measurements to AAVSO (observer MMAE)

8. R R

9. AAVSO Screenshot

10. R Ophiuchi We selected R Ophiuchi, a variable star in the constellation Draco R Ophiuchi is a “Mira-type” or long-peroid variable star Star changes on average from magnitude 7 to 13.8 over a period of 10 months (306.5 days) R Ophiuchi was predicted to peak around June 20 (Sky & Telescope, July 2013)

11. R Oph Ophiuchus Newsworthy in 2011 [click]click

12. AAVSO Star Chart

13. R Ophiuchi Results DateTimeMagnitude*Uncertainty** 6/2112:34 am7.80 0.00172 6/291:44 am8.30 0.02274 7/1011:28 pm8.26 0.00263 7/141:24 am8.16 0.00104 7/1811:46 pm8.13 0.00053 *7—13.8 **1/SNR

14. R Ophiuchi Light Curve

15. SS Cygni SS Cygni, a well-known variable star in the constellation Cygnus Cataclysmic variable (dwarf nova class) Magnitude 12.2 to 8.3 Outburst every 4-10 weeks, duration of 1-2 weeks Consists of red dwarf and white dwarf in fast orbit (6.5 hours) Newsworthy [click]click

16. SS Cygni Results DateTimeMagnitude*Uncertainty** 7/1410:06 pm12.136 0.0168 7/1811:09 pm12.233 0.01149 *7—13.8 **1/SNR

17. SS Cygni Light Curve

18. Barnard’s Star One of the nearest stars to earth (6 LY) Exhibits greatest proper motion of any star Project: Take images of Barnard’s Star each summer, record its proper motion

19. Barnard’s Star July 2013

20. Asteroid Astrometry Goal: Measure the position of known asteroids Provide reports of asteroid position to the Minor Planet Center We worked as a group within the International Asteroid Search Collaboration (IASC)IASC

21. Procedure Obtain CCD images of predicted NEO asteroid positions Stack images, search for moving objects using Astrometrica software Prepare reports in a standard format, submit to Dr. Patrick Miller at IASC

22. Weather

23. Clear Sky Charts [click]click

24. Sensing the Cosmos

25. L to R: Emily, Vikas, & Linda