15:00 17:00 19:00 21:00 23:00 01:00 03:00 05:00 07:00 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 Time in zone EST5EDT on 2019-11-21 (local date at sunset) Airmass 100.0 -1.0 100.0 -1.0 15:00, 1.92 15:05, 1.88 15:10, 1.84 15:15, 1.80 15:20, 1.76 15:25, 1.73 15:30, 1.69 15:35, 1.66 15:40, 1.63 15:45, 1.60 15:50, 1.57 15:55, 1.55 16:00, 1.52 16:05, 1.50 16:10, 1.47 16:15, 1.45 16:20, 1.43 16:25, 1.41 16:30, 1.39 16:35, 1.37 16:40, 1.35 16:45, 1.33 16:50, 1.31 16:55, 1.30 17:00, 1.28 17:05, 1.27 17:10, 1.25 17:15, 1.24 17:20, 1.22 17:25, 1.21 17:30, 1.20 17:35, 1.19 17:40, 1.18 17:45, 1.16 17:50, 1.15 17:55, 1.14 18:00, 1.13 18:05, 1.12 18:10, 1.12 18:15, 1.11 18:20, 1.10 18:25, 1.09 18:30, 1.08 18:35, 1.08 18:40, 1.07 18:45, 1.06 18:50, 1.06 18:55, 1.05 19:00, 1.05 19:05, 1.04 19:10, 1.04 19:15, 1.03 19:20, 1.03 19:25, 1.03 19:30, 1.02 19:35, 1.02 19:40, 1.02 19:45, 1.01 19:50, 1.01 19:55, 1.01 20:00, 1.01 20:05, 1.01 20:10, 1.00 20:15, 1.00 20:20, 1.00 20:25, 1.00 20:30, 1.00 20:35, 1.00 20:40, 1.00 20:45, 1.00 20:50, 1.00 20:55, 1.00 21:00, 1.00 21:05, 1.01 21:10, 1.01 21:15, 1.01 21:20, 1.01 21:25, 1.01 21:30, 1.02 21:35, 1.02 21:40, 1.02 21:45, 1.03 21:50, 1.03 21:55, 1.04 22:00, 1.04 22:05, 1.05 22:10, 1.05 22:15, 1.06 22:20, 1.06 22:25, 1.07 22:30, 1.07 22:35, 1.08 22:40, 1.09 22:45, 1.10 22:50, 1.10 22:55, 1.11 23:00, 1.12 23:05, 1.13 23:10, 1.14 23:15, 1.15 23:20, 1.16 23:25, 1.17 23:30, 1.18 23:35, 1.19 23:40, 1.21 23:45, 1.22 23:50, 1.23 23:55, 1.25 0:00, 1.26 0:05, 1.27 0:10, 1.29 0:15, 1.31 0:20, 1.32 0:25, 1.34 0:30, 1.36 0:35, 1.38 0:40, 1.40 0:45, 1.42 0:50, 1.44 0:55, 1.46 1:00, 1.49 1:05, 1.51 1:10, 1.54 1:15, 1.56 1:20, 1.59 1:25, 1.62 1:30, 1.65 1:35, 1.68 1:40, 1.71 1:45, 1.75 1:50, 1.78 1:55, 1.82 2:00, 1.86 2:05, 1.90 2:10, 1.95 2:15, 1.99 2:20, 2.04 2:25, 2.09 2:30, 2.14 2:35, 2.20 2:40, 2.26 2:45, 2.32 2:50, 2.38 2:55, 2.45 3:00, 2.52 3:05, 2.60 3:10, 2.68 3:15, 2.76 3:20, 2.85 3:25, 2.95 3:30, 3.05 3:35, 3.16 3:40, 3.28 3:45, 3.40 3:50, 3.53 3:55, 3.68 4:00, 3.83 4:05, 3.99 4:10, 4.17 4:15, 4.36 4:20, 4.57 4:25, 4.79 4:30, 5.04 4:35, 5.30 4:40, 5.59 4:45, 5.91 4:50, 6.26 4:55, 6.65 5:00, 7.07 5:05, 7.54 5:10, 8.07 5:15, 8.64 5:20, 9.28 5:25, 9.99 5:30, 10.76 5:35, 11.57 5:40, 12.39 5:45, 13.09 5:50, 13.33 5:55, 13.33 6:00, 13.33 6:05, 13.33 6:10, 13.33 6:15, 13.33 6:20, 13.33 6:25, 13.33 6:30, 13.33 6:35, 13.33 6:40, 13.33 6:45, 13.33 6:50, 13.33 6:55, 13.33 7:00, 13.33 Airmass plot for M 31 RA = 00:42:44.32, Dec = +41:16:07.5; Middlebury College Observatory, VT. Lat, long = 44.0134, -73.1813 90 56 45 38 33 30 27 24 Elevation (degrees)