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NLC 2013-05-24/25

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: 2013-05-24/25

   UT     forms  bright   height   azimuth   comments
                  ness   top bot  left rght  e.g. weather
--------  -----  ------  --- ---  ---- ----  --------------------------------
21:15:01  0                                  cirrus on left to h 20
21:30:01  0                                  cirrus on left to h 10 or 15
21:45:02  0                                  cirrus on left to h 10
22:00:02  0                                  cirrus on left to h 10
22:15:09  I?        1     20  10             cirrus on left to h 10
22:30:19  I         2     18   8   -30   25  cirrus on left to h 10
22:45:32  I,IV      2     13      <-35   20  cirrus on left to h 10
23:00:32  I         2     10      <-25   30  cirrus on left to h 10
23:15:32  I,II      2     10       -25   25  cirrus on left to h 5
23:30:47  I         2      8       -25   25
23:45:47  I         2      6       -15   20
00:00:46  I         2      5       -15   20
00:15:47  I         1      5       -15   15
00:30:47  IV        1      5       -15   10
00:45:46  IV        2      5       -20   15
01:00:54  II,IV     2      5       -25  >35
01:15:32  II,IV     1      5       -30   30
01:30:32  I         1      8       -30  >35
01:45:09  II        1      5        20  >35
02:00:10  IV        1     20       -10   20
02:15:03  IV        1     25       -10   15
02:30:02  0
02:45:01  0
03:00:01  0

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: 2013/05/24-25
Start: 22:15
End: 02:15
Forms: I,II,IV
Max elevation:  25
Max brightness: 2
Comments:
<a href="http://www.chiandh.me.uk/nlccam/20130524-25.shtml">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)
-------- ------ ----- ----- ----- -----  ----- -------------------
22:15:09  2.000 333.0  -9.4  -1.5  62.9  0-255 q2894.jpg m2894.jpg
22:30:19  4.000 336.5 -10.3  -2.1  28.9  0-255 q2898.jpg
22:45:32  8.000 340.0 -11.1  -2.6  18.2  0-255 q2903.jpg
23:00:32  8.000 343.5 -11.8  -3.1  13.5  0-255 q2908.jpg
23:15:32  8.000 347.1 -12.3  -3.4  10.9  0-255 q2914.jpg
23:30:47 15.000 350.7 -12.7  -3.6   9.3  0-255 q2920.jpg
23:45:47 15.000 354.3 -13.0  -3.8   8.4  0-255 q2926.jpg
00:00:46 15.000 357.9 -13.1  -3.9   8.0  0-255 q2932.jpg
00:15:47 15.000   1.5 -13.1  -3.9   8.0  0-255 q2938.jpg
00:30:47 15.000   5.1 -13.0  -3.8   8.3  0-255 q2944.jpg
00:45:46 15.000   8.6 -12.8  -3.7   9.1  0-255 q2950.jpg
01:00:54 15.000  12.2 -12.4  -3.4  10.6  0-255 q2957.jpg m2957.jpg
01:15:32  8.000  15.7 -11.9  -3.1  12.9  0-255 q2962.jpg m2962.jpg
01:30:32  8.000  19.2 -11.2  -2.7  17.1  0-255 q2968.jpg m2968.jpg
01:45:09  2.000  22.6 -10.5  -2.3  25.6  0-255 q2971.jpg m2971.jpg
02:00:10  2.000  26.1  -9.6  -1.7  50.6  0-255 q2975.jpg m2975.jpg
02:15:03  1.000  29.4  -8.7  -0.9 118.7  0-255 q2977.jpg m2977.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).