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NLC 2018-06-21/22

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: 2018-06-21/22

   UT     forms  bright   height   azimuth   comments
                  ness   top bot  left rght  e.g. weather
--------  -----  ------  --- ---  ---- ----  --------------------------------
21:45:01  0                                  clear
22:00:02  0                                  clear
22:15:01  0                                  clear
22:30:02  0                                  clear
22:45:08  0                                  clear
23:00:10  0                                  clear
23:15:19  IV         1    10            >35  some cloud on left to h 10
23:30:32  IV         2    15            >35  some cloud on left to h 10
23:45:31  IV         2    12            >35  some cloud to h 10 or 15
00:00:32  IV         2    12       350  >35  through cloud
00:15:32  IV         2    17       340       through cloud, thin cloud left of NLC
00:30:33  IV         2    20                 through cloud, thin cloud left and above
00:45:19  II,IV      2    20                 through cloud, thin cloud above
01:00:19  NLC        2    22                 through cloud
01:15:18  NLC        1                       through cloud
01:30:09  X                                  widespread cloud
01:45:02  X                                  widespread cloud
02:00:02  X                                  widespread cloud
02:15:01  X                                  widespread cloud
02:30:04  X                                  widespread cloud
02:45:01  X                                  widespread cloud

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: 2018/06/21-22
Start: 23:15
End: 01:15
Forms: II,IV
Max elevation: 22
Max brightness: 2
Comments: through cloud
http://www.chiandh.eu/nlccam/20180621-22.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)
-------- ------ ----- ----- ----- -----  ----- -------------------
23:15:19  4.000 346.2  -9.6  -1.7  50.2  0-255 q9900.jpg m9900.jpg
23:30:32  8.000 349.7 -10.1  -2.0  34.2  0-255 q9904.jpg
23:45:31  8.000 353.2 -10.4  -2.2  27.4  0-255 q9908.jpg
00:00:32  8.000 356.7 -10.6  -2.3  24.3  0-255 q9912.jpg
00:15:32  8.000   0.2 -10.6  -2.3  23.5  0-255 q9916.jpg
00:30:33  8.000   3.7 -10.6  -2.3  24.6  0-255 q9920.jpg
00:45:19  4.000   7.1 -10.4  -2.2  27.8  0-255 q9923.jpg
01:00:19  4.000  10.6 -10.1  -1.9  35.2  0-255 q9927.jpg
01:15:18  4.000  14.1  -9.6  -1.6  52.3  0-255 q9931.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).