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NLC 2019-06-27/28

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: 2019-06-27/28

   UT     forms  bright   height   azimuth   comments
                  ness   top bot  left rght  e.g. weather
--------  -----  ------  --- ---  ---- ----  --------------------------------
21:45:01  0                                  clear, thin band of haze at h 5 or 10
22:00:01  0                                  clear, thin band of haze at h 5 or 10
22:15:02  0                                  clear, thin band of haze at h 5 or 10
22:30:02  NLC?       1    12        10   25  clear, thin band of haze at h 5 or 10
22:45:03  NLC?       1    12        10   35  clear, thin band of haze at h 5 or 10
23:00:02  II         1    10       340  >35  clear
23:15:09  II         2    10       330  >35  cloud to h 4
23:30:09  II         3    12      <325  >35  cloud to h 4
23:45:10  II         3    12      <325  >35  cloud to h 4
00:00:09  II,III     4    15      <325  >35  cloud to h 5
00:15:10  II,III     4    15      <325  >35  cloud to h 5
00:30:19  II,III     4    15      <325  >35  through cloud
00:45:19  II,III     3    15      <325  >35  through cloud
01:00:19  III        2    15                 through cloud
01:15:19  X                                  patchy cloud
01:30:18  X                                  patchy cloud
01:45:09  X                                  patchy cloud
02:00:06  X                                  patchy cloud
02:15:06  X                                  overcast
02:30:05  X                                  overcast
02:45:04  X                                  overcast

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: 2019-06-27/28
Start: 22:30
End: 01:00
Forms: II,III
Max elevation: 15
Max brightness: 4
Comments: some cloud
http://www.chiandh.eu/nlccam/20190627-28.html

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)
-------- ------ ----- ----- ----- -----  ----- -------------------
22:30:02  0.500 335.6  -7.6   0.0 154.1  0-255 q8376.jpg m8376.jpg
22:45:03  1.000 339.0  -8.4  -0.7 131.3  0-255 q8378.jpg m8378.jpg
23:00:02  1.000 342.4  -9.1  -1.3  84.3  0-255 q8380.jpg m8380.jpg
23:15:09  2.000 345.8  -9.7  -1.7  47.5  0-255 q8383.jpg
23:30:09  2.000 349.3 -10.2  -2.0  32.5  0-255 q8386.jpg
23:45:10  2.000 352.8 -10.5  -2.2  25.9  0-255 q8390.jpg
00:00:09  2.000 356.3 -10.7  -2.4  23.0  0-255 q8394.jpg
00:15:10  2.000 359.8 -10.8  -2.4  22.0  0-255 q8398.jpg
00:30:19  4.000   3.3 -10.7  -2.4  22.8  0-255 q8403.jpg
00:45:19  4.000   6.8 -10.5  -2.3  25.5  0-255 q8407.jpg
01:00:19  4.000  10.3 -10.2  -2.0  31.5  0-255 q8411.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).