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NLC 2013-06-25/26

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: 2013-06-25/26

   UT     forms  bright   height   azimuth   comments
                  ness   top bot  left rght  e.g. weather
--------  -----  ------  --- ---  ---- ----  --------------------------------
21:45:01  0                                  cirrus to h 10
22:00:05  0                                  cirrus to h 10
22:15:02  0                                  cirrus to h 10
22:30:02  0                                  cirrus to h 10
22:45:02  0                                  cirrus to h 10
23:00:10  IV        2     12                 cirrus below
23:15:19  IV        2     15                 through cloud
23:30:18  X                                  almost overcast
23:45:32  X                                  almost overcast
00:00:32  I         2     20                 through cloud
00:15:32  I         2     15                 through cloud
00:30:32  IV        2     12                 through cloud
00:45:32  IV        2                        through cloud
01:00:32  X                                  widespread cloud
01:15:19  I         1                        through cloud
01:30:09  I         1                        through cloud
01:45:10  X                                  widespread cloud
02:00:06  X                                  cloud to h 15
02:15:05  X                                  almost overcast
02:30:05  X                                  widespread cloud
02:45:05  X                                  widespread cloud

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: 2013/06/25-26
Start: 23:00
End: 01:30
Forms: I,IV
Max elevation: 20
Max brightness: 2
Comments:
<a href="http://www.chiandh.me.uk/nlccam/20130625-26.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)
-------- ------ ----- ----- ----- -----  ----- -------------------
23:00:10  2.000 342.5  -9.1  -1.3  85.0  0-255 q5174.jpg m5174.jpg
23:15:19  4.000 346.0  -9.7  -1.7  48.0  0-255 q5177.jpg
00:00:32  8.000 356.5 -10.7  -2.4  23.3  0-255 q5189.jpg
00:15:32  8.000   0.0 -10.7  -2.4  22.5  0-255 q5193.jpg
00:30:32  8.000   3.5 -10.7  -2.4  23.3  0-255 q5197.jpg
00:45:32  8.000   7.0 -10.5  -2.2  26.3  0-255 q5201.jpg
01:15:19  4.000  13.9  -9.7  -1.7  47.3  0-255 q5208.jpg
01:30:09  2.000  17.3  -9.1  -1.3  82.3  0-150 q5210.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).