The University of Arizona

Second GMT Mirror Casting to Begin

The second of seven 8.4 meter (28ft) mirrors for the Giant Magellan Telescope's primary casting is taking place this week.  You can view the live flash images from the furnace:
Here's an approximate schedule for the melting of the glass into the mold for the GMT2 8.4m casting (as presently forseen).
Friday, January 13
22:00 MST  Furnace starts turning  (750 C)
23:00 MST  Furnace rotating at 4.8 RPM (762 C) Saturday, January 14
02:00 MST  Noticeable glass softening (810 C)
04:30 MST  Glass blocks slumping (850 C)
07:30 MST  Glass melting        (900 C)
13:00 MST  Smoothing of glass surface (980 C)
17:30 MST  Glass clear          (1070 C)
20:00 MST  Maximum Temeperature (1165 C)
midnight     Start cooling        (1165 C)