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NLC 2018-06-18/19

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: 2018-06-18/19

   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  I          1    40      <325   30  clear
22:30:02  I,III      2    45      <325   30  clear
22:45:02  IV         2    45      <325  >35  clear
23:00:02  IV         2    35      <325  >35  clear
23:15:17  I,IV       3    30      <325  >35  clear, thin patchy cloud above
23:30:18  I,IV       4    25      <325  >35  clear, thin patchy cloud above
23:45:19  I,IV       5    20      <325  >35  clear, thin patchy cloud above
00:00:10  I,IV       5    17      <325  >35  clear, thin patchy cloud above
00:15:09  I,IV       5    17      <325  >35  clear, thin patchy cloud above
00:30:10  I,IV       5    15      <325  >35  clear, thin patchy cloud above
00:45:10  I,IV       4    17      <325  >35  thin cloud patches
01:00:08  I,IV       4    22      <325  >35  thin cloud patches
01:15:08  II,III,IV  4    30      <325  >35  thin cloud patches
01:30:02  II,III,IV  4    40      <325  >35  cloud patches to h 20
01:45:02  II,III     3    45      <325  >35  cloud patches to h 15
02:00:02  III        2    45       335   30  cloud to h 10 or 15, higher patches
02:15:02  III        2    50                 cloud to h 10 or 15, higher patches
02:30:05  III        1    30                 cloud to h 10
02:45:04  III        1    20                 cloud to h 10

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: 2018/06/18-19
Start: 22:15
End: 02:45
Forms: I,II,III,IV
Max elevation: 50
Max brightness: 5
Comments: thin patchy cloud
http://www.chiandh.eu/nlccam/20180618-19.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)
-------- ------ ----- ----- ----- -----  ----- -------------------
22:15:01  0.250 332.7  -6.7   1.0 163.9  0-255 q9716.jpg m9716.jpg
22:30:02  0.500 336.1  -7.6  -0.0 153.7  0-255 q9718.jpg m9718.jpg
22:45:02  1.000 339.4  -8.4  -0.7 130.8  0-255 q9720.jpg
23:00:02  1.000 342.9  -9.1  -1.3  84.7  0-255 q9722.jpg
23:15:17  4.000 346.4  -9.7  -1.7  48.3  0-255 q9726.jpg
23:30:18  4.000 349.8 -10.1  -2.0  33.4  0-255 q9729.jpg
23:45:19  4.000 353.3 -10.4  -2.2  26.9  0-255 q9733.jpg
00:00:10  2.000 356.8 -10.6  -2.3  24.0  0-255 q9736.jpg
00:15:09  2.000   0.3 -10.7  -2.4  23.3  0-255 q9740.jpg
00:30:10  2.000   3.8 -10.6  -2.3  24.3  0-255 q9744.jpg
00:45:10  2.000   7.3 -10.4  -2.2  27.7  0-255 q9748.jpg
01:00:08  2.000  10.7 -10.1  -1.9  35.1  0-255 q9752.jpg
01:15:08  2.000  14.2  -9.6  -1.6  52.3  0-255 q9756.jpg
01:30:02  1.000  17.6  -9.0  -1.2  91.8  0-255 q9758.jpg
01:45:02  1.000  21.0  -8.3  -0.6 135.3  0-255 q9760.jpg
02:00:02  0.500  24.4  -7.5   0.1 155.6  0-255 q9762.jpg
02:15:02  0.250  27.7  -6.6   1.2 164.9  0-255 q9764.jpg
02:30:05  0.125  31.0  -5.6   3.3 170.1  0-255 q9767.jpg m9767.jpg
02:45:04  0.067  34.3  -4.4  11.4 173.5  0-255 q9769.jpg m9769.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).