1. Obtain the sky brightness in optical B, V, and R photometric bands above Dome A site To measure the cloud cover extent during the 2009 and 2010 winter seasons Extended to 2011 by NSF To provide aurora and airglow statistics Photometry of bright target stars in field with unprecedented window function $Meet budget of ~$50k (NSF OPP/AST award) excluding logistical costs All logistical costs provided by PRIC/China collaboration Gattini-DomeA Goals of experiment

2. 90 o FoV transit camera + Optic ‘IFW’ filter wheel (B, V, R, >650nm) Apogee Alta ‘U4000’ 2kx2k interline CCD with 7.4 micron pixels AF DX Fisheye-Nikkor 10.5mm f/2.8G ED results in ~2.4arcmin/pix, aperture ~few mm Continuous observations: – 100s B 30s B – 100s V 30s V – 100s R 30s R – 100s OH 30s OH – 100s dark – BIAS frame – REPEAT Camera, Data

3. V sky brightness, whole season

4. CAUTION: more work needed to assess effect of imperfect baffling (are we measuring true sky brightness or instrument performance?)

5. Photometry

6. Strongly suspect “cloud” equals local snow obscuration lifted by wind in many cases ‘Cloud’ cover