Moment

Figure 3 — Panoramic night view at Mallory Hill, 2007 December12/13Figure 2 — OMI Photometric performance with Zθ = 0°, 1.25˝FWHM (wL = 420-870 nm)Additionally, we wanted the highest possible elevationand a treeless area to minimize microclimates caused bya forested canopy. The ONLY area that meets all of thesecriteria is near the small town of Denbigh, which is locatedabout 100 km northwest of Kingston, Ontario. Road andtopographic maps were examined to locate a specific site.The chosen location is identified on topographic maps asMallory Hill. It has an altitude of 400 metres with 80 acresof cleared land on a hilltop. The area has a good pavedroad running nearby and no higher elevations in the westfor optimum airflow over the local terrain. Sky brightnessmeasurements were made over several months using a SkyQuality Meter by Unihedron with readings of 21.82 mag/arcsec 2 ; no direct lights are visible from the site. There issufficient buffer to allow for 100 years of continuing darkskies in the face of expected development. According toEnvironment Canada, we should expect more than 1000nighttime cloud-free hours per annum.Figure 4 — Sky-brightness map of north-east North America showingthe location of Mallory Hill with major Canadian observatoriesidentified. Based on work by Cinzano and Thiene, Italy 1998Latitude N 45° 01´ 37.4“Longitude W 77º 05´ 57.4“Altitude375 metresSky Brightness 21.82 mag/arcsec 2 (v) (42° FWHM )Horizon Exposure < 2°Ground 80 acres cleared land on a hilltop, 12“top soil with a granite baseClear Dark Hours per year ~1100 (Environment Canada forKingston)Table 1. OMI site performance/characteristicsFigure 5 — The Milky Way at Mallory Hill. Mosaic of 9 images witha 50mm @ f/4, 350D, 20-minutes exp. per frame ©2007 NathanChamaillardApril / avril 2009JRASCCelebrating the International Year of Astronomy (IYA2009)55