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NLC 2013-05-30/31

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: 2013-05-30/31

   UT     forms  bright   height   azimuth   comments
                  ness   top bot  left rght  e.g. weather
--------  -----  ------  --- ---  ---- ----  --------------------------------
21:30:01  0
21:45:04  IV        1     40  10     0   30  cloud to h 5 on left
22:00:05  II,IV     2     40  10   -15   35  cloud to h 5, some higher patches
22:15:02  IV        3     45       -20  >35  cloud to h 10, some higher patches
22:30:18  III,IV    3     40      <-35  >35  cloud to h 10
22:45:19  NLC       3                        through cloud
23:00:31  X                                  almost overcast
23:15:32  X                                  almost overcast
23:30:32  I         4     13      <-35  >15  through cloud
23:45:53  I         4     13      <-35  >30  cloud below
00:00:53  NLC       3     10                 through cloud
00:15:53  X                                  cloud to h 15, higher on right
00:30:54  X                                  almost overcast
00:45:54  X                                  almost overcast
01:00:32  NLC       2                        through cloud
01:15:32  I         3                        through cloud
01:30:19  NLC       2                        through cloud
01:45:19  NLC       2                        through cloud
02:00:10  NLC       2                        through cloud
02:15:06  X                                  some cloud patches
02:30:05  X                                  some cloud and haze
02:45:05  X                                  some cloud and haze
03:00:01  X                                  some cloud and haze

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: 2013/05/30-31
Start: 21:45
End: 02:00
Forms: I,II,III,IV
Max elevation:  45
Max brightness: 4
Comments:
<a href="http://www.chiandh.me.uk/nlccam/20130530-31.shtml">Images</a>.
Through cloud.

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)
-------- ------ ----- ----- ----- -----  ----- -------------------
21:45:04  0.250 326.4  -6.3   1.7 166.6  0-255 q3454.jpg m3454.jpg
22:00:05  0.500 329.8  -7.4   0.2 156.9  0-255 q3456.jpg
22:15:02  1.000 333.1  -8.4  -0.7 131.3  0-255 q3457.jpg
22:30:18  4.000 336.6  -9.3  -1.4  68.2  0-255 q3461.jpg
22:45:19  4.000 340.0 -10.1  -2.0  33.6  0-255 q3464.jpg
23:30:32  8.000 350.6 -11.7  -3.0  13.8  0-255 q3478.jpg
23:45:53 15.000 354.2 -12.0  -3.2  12.2  0-255 q3485.jpg
00:00:53 15.000 357.8 -12.1  -3.3  11.5  0-255 q3491.jpg
01:00:32  8.000  11.9 -11.4  -2.9  15.5  0-255 q3514.jpg m3514.jpg
01:15:32  8.000  15.4 -10.9  -2.5  19.8  0-255 q3519.jpg
01:30:19  4.000  18.8 -10.3  -2.1  28.6  0-255 q3523.jpg
01:45:19  4.000  22.3  -9.6  -1.6  52.6  0-255 q3527.jpg
02:00:10  2.000  25.6  -8.7  -1.0 113.0  0-255 q3529.jpg m3529.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).