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NLC 2012-06-24/25

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 dSLR with limited field of view A ~325-35, h ~0-40
          images every 15 min
Date: 2012-06-24/25

  UT   forms  bright   height   azimuth   comments
               ness   top bot  left rght  e.g. weather
-----  -----  ------  --- ---  ---- ----  --------------------------------
21:45  X                                  cloud to h 15
22:00  X                                  cloud to h 10, on left to h 30
22:15  X                                  cloud to h 15, higher patches
22:30  I,III,IV   2    35      <325  >35  cloud patches to h 15
22:45  II,III,IV  3    40   8  <325  >35  cloud patches to h 10
23:00  II,III,IV  3    30   5  <325  >35  some cloud patches
23:15  I,III,IV   4    27   5  <325  >35  some cloud patches to h 10
23:30  III,IV     4    18   5  <325  >35  some cloud patches
23:45  II,IV      4    15   3  <325  >35  through cloud
00:00  II,IV      4    15   5  <325  >35  through cloud
00:15  III,IV     3    18   5   325  >35  some cloud patches
00:30  IV         2    18       335  >35  through cloud
00:45  IV         2    15        15  >35  through cloud
01:00  I,IV       2    15       335  >35  through cloud
01:15  I,IV       2    10       330   30  through cloud
01:30  I          1    10      <325   35  through cloud
01:45  X                                  cloud to h 15 or 20
02:00  X                                  cloud widespread
02:15  X                                  cloud widespread
02:30  X                                  cloud widespread
02:45  X                                  cloud widespread

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: 2012/06/24-25
Start: 22:30
End: 01:30
Forms: I,II,III,IV
Max elevation: 40
Max brightness: 4
Comments:
<a href="http://www.chiandh.me.uk/p/NLC_2012-06-24/25">Images</a>.

forms: I: veil
       II: bands
       III: waves
       IV: whirls
       O: 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  0.300 335.7  -7.6   0.0 154.5  0-255 q00096.jpg m00096.jpg
22:45  1.000 339.1  -8.4  -0.7 132.5  0-255 q00099.jpg m00099.jpg
23:00  1.000 342.5  -9.1  -1.3  86.8  0-255 q00100.jpg
23:15  1.300 346.0  -9.7  -1.7  49.3  0-255 q00103.jpg
23:30  1.300 349.4 -10.1  -2.0  33.6  0-255 q00105.jpg
23:45  1.300 352.9 -10.4  -2.2  26.8  0-255 q00109.jpg
00:00  4.000 356.4 -10.6  -2.3  23.7  0-255 q00114.jpg
00:15  4.000 359.9 -10.7  -2.4  22.8  0-255 q00118.jpg
00:30  4.000   3.4 -10.6  -2.3  23.6  0-255 q00122.jpg
00:45  3.200   6.9 -10.4  -2.2  26.5  0-255 q00126.jpg
01:00  2.500  10.4 -10.1  -2.0  33.1  0-255 q00129.jpg
01:15  1.300  13.9  -9.7  -1.7  48.0  0-255 q00132.jpg
01:30  1.000  17.3  -9.1  -1.3  84.0  0-255 q00134.jpg m00134.jpg

exp: Exposure time in seconds (400 ISO, f/3.5).
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).