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NLC 2011-07-02/03

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: 2011-07-02/03

  UT   forms  bright   height   azimuth   comments
               ness   top bot  left rght  e.g. weather
-----  -----  ------  --- ---  ---- ----  --------------------------------
21:45  X                                  cloud
22:00  X                                  cloud
22:15  X                                  cloud
22:30  X                                  cloud
22:45  X                                  cloud
23:00  0                                  cloud to h 10, higher on right
23:15  NLC?                               through cirrus
23:30  I,II       3    12       340  >35  through cirrus
23:45  I,II       3    14      <325  >35  some cirrus
00:00  III,IV     4    12      <325  >35  some cirrus/haze
00:15  II,IV      4    12      <325  >35  haze on horizon
00:30  II,IV      5    14      <325  >30  haze on horizon
00:45  II,IV      5    15      <325   30  haze on horizon
01:00  III,IV     5    18      <325   30  haze on horizon
01:15  III,IV     5    21      <325   32  haze on horizon
01:30  III,IV     5    22      <325  >35  haze on horizon
01:45  III,IV     4    24      <325   35  haze on horizon
02:00  IV         3    27      <325   35  haze on horizon
02:15  IV         2    29      <325   17  haze on horizon
02:30  I,IV       2    25      <325    0  haze on horizon
02:45  I          1    22      <325  345  haze on horizon

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: 2011/07/02-03
Start: 23:15
End: 02:45
Forms: I,II,III,IV
Max elevation: 29
Max brightness: 5
Comments:
<a href="http://www.chiandh.me.uk/p/NLC_2011-07-02/03">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  2.000 345.6 -10.0  -1.9  37.1  0-255 q14930.jpg m14930.jpg
23:30  3.200 349.0 -10.4  -2.2  26.5  0-255 q14934.jpg
23:45  4.000 352.5 -10.8  -2.4  21.6  0-255 q14938.jpg
00:00  2.500 356.1 -11.0  -2.6  19.3  0-255 q14941.jpg
00:15  2.500 359.6 -11.1  -2.6  18.5  0-255 q14945.jpg
00:30  2.500   3.1 -11.0  -2.6  19.0  0-255 q14949.jpg
00:45  2.000   6.6 -10.9  -2.5  20.8  0-255 q14953.jpg
01:00  1.300  10.1 -10.5  -2.3  24.9  0-255 q14957.jpg
01:15  1.300  13.6 -10.1  -2.0  33.4  0-255 q14960.jpg
01:30  0.800  17.0  -9.6  -1.6  54.3  0-255 q14963.jpg
01:45  0.800  20.5  -8.9  -1.1 102.8  0-255 q14966.jpg
02:00  0.400  23.9  -8.1  -0.4 143.5  0-255 q14968.jpg
02:15  0.200  27.2  -7.2   0.5 159.8  0-255 q14970.jpg
02:30  0.100  30.5  -6.2   1.9 167.4  0-255 q14972.jpg
02:45  0.040  33.8  -5.1   5.2 171.8  0-255 q14974.jpg m14974.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).