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NLC 2018-08-08/09

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: 2018-08-08/09

   UT     forms  bright   height   azimuth   comments
                  ness   top bot  left rght  e.g. weather
--------  -----  ------  --- ---  ---- ----  --------------------------------
20:45:05  0                                  clear
21:00:06  0                                  clear
21:15:09  0                                  clear
21:30:19  0                                  clear
21:45:52  0                                  almost clear
22:01:24  0                                  almost clear
22:17:33  0                                  clear
22:32:33  0                                  some cloud
22:46:23  0                                  cloud above h 5
01:02:33  0                                  clear
01:17:33  0                                  clear
01:32:33  0                                  clear
01:47:33  II         2     4        15   25  clear
02:02:33  II         3     4        15   35  clear
02:17:33  II         3     5        15  >35  clear
02:31:24  I,II       4     8       355  >35  clear
02:45:53  I          3    11            >35  clear
03:00:19  NLC        1    15                 clear
03:15:10  0                                  clear
03:30:02  0                                  cloud on left to h 10
03:45:01  0                                  cloud on left to h 15
04:00:01  X                                  cloud on left

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: 2018/08/08-09
Start: 01:45
End: 03:00
Forms: I,II
Max elevation: 15
Max brightness: 4
Comments: Clear.
http://www.chiandh.eu/nlccam/20180808-09.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

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

Name: Horst Meyerdierks
Country: Scotland
Location: Edinburgh
Date: 2018/08/08-09
Start: 20:45
End: 01:30
Comments: mostly clear

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)
-------- ------ ----- ----- ----- -----  ----- -------------------
01:47:33 60.000  22.3 -15.8  -5.4   2.7  0-255 q4216.jpg
02:02:33 60.000  25.9 -14.9  -4.9   4.1  0-255 q4222.jpg
02:17:33 60.000  29.5 -13.9  -4.3   5.9  0-255 q4228.jpg
02:31:24 30.000  32.8 -12.9  -3.8   8.6  0-255 q4233.jpg
02:45:53 15.000  36.1 -11.8  -3.1  13.4  0-255 q4239.jpg
03:00:19  4.000  39.4 -10.5  -2.3  24.9  0-255 q4243.jpg m4243.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).