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NLC 2011-06-23/24

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: 2011-06-23/24

  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  0
22:45  0
23:00  0
23:15  NLC?       1     7        18   23
23:30  I          1    12      <325   25
23:45  I          1    12      <325   30
00:00  I,II       2    13       340  >35
00:15  I,II       2    10       345  >35
00:30  I,II       3    11       345  >35
00:45  II         3    12       350  >35
01:00  II         3    12       350  >35
01:15  II         2    10       350  >35
01:30  II         1     8       355  >35
01:45  II?        1     5        25   30
02:00  0
02:15  0
02:30  0
02:45  X

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: 2011/06/23-24
Start: 23:15
End: 01:45
Forms: I,II
Max elevation: 13
Max brightness: 3
Comments:
<a href="http://www.chiandh.me.uk/p/NLC_2011-06-23/24">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)
----- ------ ----- ----- ----- -----  ----- ---------------------
23:15  1.300 346.1  -9.6  -1.7  50.5  0-255 q14419.jpg m14419.jpg
23:30  2.500 349.5 -10.1  -2.0  34.4  0-255 q14422.jpg m14422.jpg
23:45  3.200 353.0 -10.4  -2.2  27.4  0-255 q14426.jpg m14426.jpg
00:00  3.200 356.5 -10.6  -2.3  24.2  0-255 q14430.jpg m14430.jpg
00:15  4.000 360.0 -10.7  -2.4  23.3  0-255 q14434.jpg m14434.jpg
00:30  3.200   3.5 -10.6  -2.3  24.2  0-255 q14438.jpg
00:45  3.200   7.0 -10.4  -2.2  27.3  0-255 q14442.jpg
01:00  2.500  10.5 -10.1  -2.0  34.3  0-255 q14445.jpg
01:15  1.300  13.9  -9.6  -1.7  50.4  0-255 q14448.jpg m14448.jpg
01:30  1.000  17.4  -9.1  -1.2  88.3  0-255 q14450.jpg m14450.jpg
01:45  0.500  20.8  -8.4  -0.7 133.2  0-255 q14452.jpg m14452.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).