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NLC 2012-06-19/20

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
          dSLR with limited field of view A ~325-35, h ~0-40
          images approximately every 15 min
Date: 2012-06-19/20

  UT   forms  bright   height   azimuth   comments
               ness   top bot  left rght  e.g. weather
-----  -----  ------  --- ---  ---- ----  --------------------------------
21:50  0                                  cloud patches to h 15
22:00  0                                  cloud patches to h 15
22:15  0                                  cloud patches to h 15
22:30  0                                  cloud patches to h 15
22:45  II         1     5   5    25  >35  through cloud, doubtful
23:00  0                                  cloud patches to h 15
23:15  II         1     5   5    20  >35  through cloud
23:30  II,IV      1     5   5    25  >35  through cloud, doubtful
23:45  II         1                       through cloud, doubtful
00:00  0
00:15  NLC        1                       through cloud
00:30  0                                  cloud on left to h 10
00:45  X                                  cloud to h 10
01:00  I          1     5   5  <325  345  through 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: 2012/06/19-20
Start: 22:45
End: 01:00
Forms: I,II,IV
Max elevation: 5
Max brightness: 1
Comments:
Through cloud.
<a href="http://www.chiandh.me.uk/p/NLC_2012-06-19/20">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)
----- ------ ----- ----- ----- -----  ----- -----------------------
22:45    0.6 339.4  -8.4  -0.7 132.3  0-255 q2457.jpg m2457.jpg
23:00    1.3 342.8  -9.1  -1.2  87.3  0-255 q2459.jpg m2459.jpg (NE)
23:15    2.5 346.2  -9.6  -1.7  50.0  0-255 q2460.jpg m2460.jpg
23:15    2.5 346.2  -9.6  -1.7  50.0  0-255 q2461.jpg m2461.jpg (NE)
23:30    3.2 349.7 -10.1  -2.0  34.3  0-255 q2462.jpg m2462.jpg
23:30    3.2 349.7 -10.1  -2.0  34.3  0-255 q2463.jpg m2463.jpg (NE)
23:45      2 353.2 -10.4  -2.2  27.4  0-255 q2465.jpg m2465.jpg
23:45      4 353.2 -10.4  -2.2  27.4  0-255 q2467.jpg m2467.jpg (NE)
00:00      4 356.7 -10.6  -2.3  24.3  0-255 q2471.jpg m2471.jpg (NE)
00:15      2   0.2 -10.6  -2.3  23.5  0-255 q2473.jpg m2473.jpg
00:15      4   0.2 -10.6  -2.3  23.5  0-255 q2475.jpg           (NE)
00:30      4   3.7 -10.6  -2.3  24.5  0-255 q2479.jpg m2479.jpg (NE)
00:45      4   7.2 -10.4  -2.2  27.8  0-255 q2483.jpg           (NE)
00:45      4   7.2 -10.4  -2.2  27.8  0-255 q2484.jpg           (NW)
01:00    1.6  10.6 -10.1  -1.9  35.2  0-255 q2487.jpg m2487.jpg
01:00    3.2  10.6 -10.1  -1.9  35.2  0-255 q2489.jpg m2489.jpg (NE)
01:00    3.2  10.6 -10.1  -1.9  35.2  0-255 q2490.jpg           (NW)
01:00    3.2  10.6 -10.1  -1.9  35.2  0-255 q2493.jpg           (E)

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).

The regular camera - a Canon EOS 300D was out of action. A manually controlled Canon EOS 400D was used instead. Many exposures were taken not looking in the standard direction (North). There was more and brighter NLC east of the standard view, latterly also west of the standard view.