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NLC 2018-06-24/25

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: 2018-06-24/25

   UT     forms  bright   height   azimuth   comments
                  ness   top bot  left rght  e.g. weather
--------  -----  ------  --- ---  ---- ----  --------------------------------
21:45:01  0                                  clear
22:00:01  0                                  clear
22:15:01  0                                  clear
22:30:01  0                                  clear
22:45:02  0                                  clear
23:00:03  IV         1    20       340   25  clear
23:15:09  IV         1    20       325   25  clear
23:30:10  IV         2    20      <325   25  clear
23:45:19  IV         2    17      <325   35  clear
00:00:18  IV         2    20      <325   35  clear
00:15:19  IV         3    15      <325   35  clear
00:30:19  IV         3    20      <325  >35  clear
00:45:19  IV         3    25      <325  >35  clear
01:00:19  III,IV     3    25      <325  >35  clear
01:15:09  III,IV     3    30      <325  >35  clear
01:30:03  III,IV     2    30      <325  >35  clear
01:45:08  III,IV     2    45                 clear, overexposed
02:00:01  IV         1    40                 clear
02:15:01  0                                  clear
02:30:01  0                                  clear
02:45:01  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: 2018/06/24-25
Start: 23:00
End: 02:00
Forms: III,IV
Max elevation: 45
Max brightness: 3
Comments: Clear.
http://www.chiandh.eu/nlccam/20180624-25.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)
-------- ------ ----- ----- ----- -----  ----- -------------------
23:00:03  1.000 342.6  -9.1  -1.2  87.3  0-255 q0071.jpg m0071.jpg
23:15:09  2.000 346.0  -9.7  -1.7  49.5  0-255 q0074.jpg m0074.jpg
23:30:10  2.000 349.5 -10.1  -2.0  33.8  0-255 q0077.jpg m0077.jpg
23:45:19  4.000 353.0 -10.4  -2.2  26.9  0-255 q0082.jpg m0082.jpg
00:00:18  4.000 356.5 -10.6  -2.3  23.8  0-255 q0086.jpg m0086.jpg
00:15:19  4.000   0.0 -10.7  -2.4  22.9  0-255 q0090.jpg m0090.jpg
00:30:19  4.000   3.5 -10.6  -2.3  23.8  0-255 q0094.jpg m0094.jpg
00:45:19  4.000   7.0 -10.4  -2.2  26.9  0-255 q0098.jpg m0098.jpg
01:00:19  4.000  10.5 -10.1  -2.0  33.6  0-255 q0102.jpg m0102.jpg
01:15:09  2.000  13.9  -9.7  -1.7  48.9  0-255 q0105.jpg m0105.jpg
01:30:03  1.000  17.3  -9.1  -1.3  85.4  0-255 q0107.jpg m0107.jpg
01:45:08  2.000  20.8  -8.4  -0.7 131.6  0-255 q0110.jpg m0110.jpg
02:00:01  0.500  24.1  -7.6   0.0 154.0  0-255 q0111.jpg m0111.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).