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NLC 2009-07-10/11

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 5 min
Date: 2009-07-10/11

  UT   forms  bright   height   azimuth   comments
               ness   top bot  left rght  e.g. weather
-----  -----  ------  -------  ---- ----  --------------------------------
21:30  X                                  cloud
21:45  X                                  cloud
22:00  X                                  cloud
22:15  X                                  cloud to h 15 or 20
22:30  X                                  patchy cloud
22:45  X                                  cloud to h 15 or 20
23:00  X                                  cloud
23:15  X                                  cloud
23:30  X                                  cloud
23:45  NLC        3                       through cloud gap
00:00  X                                  cloud
00:15  NLC        1                       through cloud gap
00:30  NLC        2                       through cloud gap
00:45  NLC        2                       through cloud gap
01:00  II         2                       amongst cirrus
01:15  I          3    10   5     0   15  some cirrus
01:30  II         1    10   5     0    5  cloud to h 5
01:45  0                                  cloud to h 5
02:00  0                                  cloud to h 10
02:15  0                                  cloud to h 10
02:30  0                                  cloud to h 10
02:45  0                                  cloud to h 10
03:00  0                                  cloud to h 10

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: 2009/07/10-11
Start: 23:45
End: 01:30
Forms: I,II
Max elevation: 10
Max brightness: 3
Comments:
<a href="http://www.chiandh.me.uk/p/NLC_2009-07-10/11>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
----- ------ ----- ----- ----- -----  ----- ------------
23:45 15.000 352.1 -11.6  -3.0  14.2  0-255 q06142.jpg
00:15 15.000 359.2 -12.0  -3.2  12.4  0-255 q06172.jpg
00:30 15.000   2.8 -11.9  -3.2  12.6  0-255 q06187.jpg
00:45 15.000   6.3 -11.8  -3.1  13.5  0-255 q06202.jpg
01:00 15.000   9.9 -11.5  -2.9  15.4  0-255 q06217.jpg
01:15  8.000  13.4 -11.0  -2.6  18.8  0-200 q06232.jpg
01:30  8.000  16.9 -10.5  -2.2  25.7  0-255 q06244.jpg

exp: Exposure time in seconds (200 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).