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NLC 2013-05-22/23

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: 2013-05-22/23

   UT     forms  bright   height   azimuth   comments
                  ness   top bot  left rght  e.g. weather
--------  -----  ------  --- ---  ---- ----  --------------------------------
21:15:01  X                                  patchy cloud
21:30:05  X                                  wide cloud band
21:45:08  X                                  almost overcast
22:00:03  X                                  almost overcast
22:15:10  X                                  almost overcast
22:30:19  X                                  almost overcast
22:45:32  X                                  widespread cloud
23:00:32  X                                  widespread cloud
23:15:47  0
23:30:47  NLC?      1      7         0   20
23:45:47  NLC?      1      7         0   20
00:01:24  NLC?      1      7         0   20  cloud above
00:15:47  NLC?      1      7         0   20  cloud above
00:30:47  I         1      7         0   30  cloud above
00:45:47  IV        1     10         0   30  cloud patches
01:00:47  X                                  patch cloud to h 10 or 20
01:15:32  X                                  almost overcast
01:30:32  IV?       1     10       -25    0  through cloud
01:45:19  0                                  widespread cloud
02:00:18  X                                  widespread cloud
02:15:02  X                                  widespread cloud
02:30:01  X                                  widespread cloud
02:45:02  X                                  almost overcast
03:00:05  X                                  almost overcast
03:15:04  X                                  almost 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: 2013/05/22-23
Start: 23:30
End: 01:30
Forms: I,IV
Max elevation:  10
Max brightness: 1
Comments:
<a href="http://www.chiandh.me.uk/nlccam/20130522-23.shtml">Images</a>.
Some 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)
-------- ------ ----- ----- ----- -----  ----- -------------------
23:30:47 15.000 350.7 -13.1  -3.8   8.1  0-255 q2716.jpg m2716.jpg
23:45:47 15.000 354.3 -13.3  -4.0   7.3  0-255 q2722.jpg m2722.jpg
00:01:24 30.000 358.1 -13.5  -4.1   7.0  0-255 q2729.jpg m2729.jpg
00:15:47 15.000   1.5 -13.5  -4.1   7.0  0-255 q2734.jpg m2734.jpg
00:30:47 15.000   5.1 -13.4  -4.0   7.3  0-255 q2740.jpg m2740.jpg
00:45:47 15.000   8.7 -13.1  -3.9   8.0  0-255 q2746.jpg m2746.jpg
01:30:32  8.000  19.3 -11.6  -2.9  14.5  0-255 q2764.jpg m2764.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).