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NLC 2011-06-28/29

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: 2011-06-28/29

  UT   forms  bright   height   azimuth   comments
               ness   top bot  left rght  e.g. weather
-----  -----  ------  --- ---  ---- ----  --------------------------------
21:45  0
22:00  0
22:15  0
22:30  II         2     4       352   30
22:45  II         2     4       346   28
23:00  II         3     5       339   25
23:15  II         3     5       333   22
23:30  II,III     4     6       330   20
23:45  I,III      3     5      <330   12
00:00  I,II       2     5      <330    3
00:15  I,II       2    12       333  358
00:30  I          1    14      <330    8
00:45  I          1    14      <330   28
01:00  I,IV       1    18      <330  >30
01:15  I,IV       2    20      <330  >30
01:30  IV         2    28      <330  >30
01:45  IV         1    30      <330   23
02:00  IV         1    33      <330  >35
02:15  IV         1    14       334  340
02:30  0
02:45  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: 2011/06/28-29
Start: 22:30
End: 02:15
Forms: I,II,III,IV
Max elevation: 33
Max brightness: 4
Comments:
<a href="http://www.chiandh.me.uk/p/NLC_2011-06-28/29">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  0.300 335.6  -7.7  -0.0 153.1  0-255 q14692.jpg m14692.jpg
22:45  0.600 338.9  -8.5  -0.8 128.4  0-255 q14694.jpg
23:00  1.000 342.3  -9.2  -1.3  79.4  0-255 q14696.jpg
23:15  1.300 345.8  -9.8  -1.7  44.9  0-255 q14699.jpg
23:30  2.500 349.3 -10.2  -2.1  31.1  0-255 q14702.jpg
23:45  3.200 352.7 -10.5  -2.3  24.9  0-255 q14706.jpg
00:00  4.000 356.2 -10.7  -2.4  22.1  0-255 q14710.jpg
00:15  4.000 359.8 -10.8  -2.5  21.2  0-255 q14714.jpg m14714.jpg
00:30  4.000   3.3 -10.8  -2.4  21.9  0-255 q14718.jpg m14718.jpg
00:45  3.200   6.8 -10.6  -2.3  24.3  0-255 q14722.jpg m14722.jpg
01:00  3.200  10.2 -10.3  -2.1  29.8  0-255 q14726.jpg m14726.jpg
01:15  2.000  13.7  -9.8  -1.8  42.0  0-255 q14729.jpg m14729.jpg
01:30  1.300  17.2  -9.3  -1.4  72.3  0-255 q14731.jpg
01:45  0.600  20.6  -8.6  -0.9 122.4  0-255 q14733.jpg m14733.jpg
02:00  0.300  24.0  -7.8  -0.2 150.7  0-255 q14735.jpg m14735.jpg
02:15  0.300  27.3  -6.9   0.8 162.7  0-255 q14738.jpg m14738.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).