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NLC 2018-06-16/17

BAA report

The report to the BAA Aurora Section gives an overview of the night, which times were cloudy, free of NLC, or with sightings of NLC.

Name of observer: Horst Meyerdierks
Location: Royal Observatory Edinburgh, 55.9N 3.2W
          unattended compact camera with limited field of view
          A ~325-35, h ~0-40; images every 15 min
Date: 2018-06-16/17

   UT     forms  bright   height   azimuth   comments
                  ness   top bot  left rght  e.g. weather
--------  -----  ------  --- ---  ---- ----  --------------------------------
21:45:02  0                                  clear
22:00:02  0                                  clear
22:15:02  0                                  clear
22:30:02  0                                  clear
22:45:02  0                                  clear
23:00:03  0                                  clear
23:15:10  0                                  clear
23:30:19  II         1    13       340   10  clear
23:45:18  II         2    16       340   30  clear
00:00:19  II         3    18       340   30  clear
00:15:19  I,II       3    20      <325   30  clear
00:30:18  I,II       3    20      <325  >35  clear
00:45:19  I,II       3    20      <325  >35  clear
01:00:19  I,II       2    20       330  >35  clear
01:15:09  I,II       2    25       335   30  clear
01:30:09  II         2    35       335   30  clear
01:45:08  II         1    40       335   30  clear
02:00:06  NLC        1    45       340   35  clear
02:15:05  0                                  clear
02:30:05  0                                  clear
02:45:04  0                                  clear

forms: I: veil
       II: bands
       III: waves
       IV: whirls
       NLC: other than or multiple of I-IV
       0: no NLC
       X: no decision possible (mist, cloud etc.)
brightness: 1: very weak
            2: clearly detected
            3: clearly visible
            4: very bright
            5: extremely bright

NLCnet report

The periods of positive sightings of NLC are reported to the NLC Observers' Home Page:

Name: Horst Meyerdierks
Country: Scotland
Location: Edinburgh
Date: 2018/06/16-17
Start: 23:30
End: 02:00
Forms: I,II
Max elevation: 45
Max brightness: 3
Comments: clear
http://www.chiandh.eu/nlccam/20180616-17.shtml

forms: I: veil
       II: bands
       III: waves
       IV: whirls
       NLC: other than or multiple of I-IV
brightness: 1: very weak
            2: clearly detected
            3: clearly visible
            4: very bright
            5: extremely bright

Images

Listed below are the images with positive sightings of NLC. These have been processed merely to adjust the brightness for underexposure. For some, there may also be an unsharp-masked version of the image.

   UT      exp    A    hSun  h15   h85  stretch  image   (masked)
-------- ------ ----- ----- ----- -----  ----- -------------------
23:30:19  4.000 349.9 -10.2  -2.0  32.0  0-255 q9613.jpg m9613.jpg
23:45:18  4.000 353.4 -10.5  -2.2  26.0  0-255 q9617.jpg m9617.jpg
00:00:19  4.000 356.9 -10.7  -2.4  23.3  0-255 q9621.jpg m9621.jpg
00:15:19  4.000   0.4 -10.7  -2.4  22.6  0-255 q9625.jpg m9625.jpg
00:30:18  4.000   3.9 -10.6  -2.3  23.7  0-255 q9629.jpg m9629.jpg
00:45:19  4.000   7.4 -10.4  -2.2  27.0  0-255 q9633.jpg m9633.jpg
01:00:19  4.000  10.9 -10.1  -2.0  34.3  0-255 q9637.jpg m9637.jpg
01:15:09  2.000  14.3  -9.6  -1.7  50.8  0-255 q9640.jpg m9640.jpg
01:30:09  2.000  17.7  -9.1  -1.2  90.0  0-255 q9643.jpg m9643.jpg
01:45:08  2.000  21.2  -8.4  -0.7 134.6  0-255 q9645.jpg m9645.jpg
02:00:06  1.000  24.5  -7.5   0.1 155.4  0-255 q9647.jpg m9647.jpg

exp: Exposure time in seconds (200 ISO, f/2.8).
A: Azimuth of the Sun (degrees).
hSun: Altitude of the Sun (degrees, negative below horizon).
h15: Max. altitude of sunlight at 15 km height (degrees).
h85: Max. altitude of sunlight at 85 km height (degrees).
stretch: Contrast stretch (0-255 means no stretch).