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NLC 2010-07-16/17

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: Stichill Eastfield, 55.7N 2.4W
          unattended dSLR with limited field of view A ~310-20, h ~0-40
          images every 15 min
Date: 2010-07-16/17

  UT   forms  bright   height   azimuth   comments
               ness   top bot  left rght  e.g. weather
-----  -----  ------  --- ---  ---- ----  --------------------------------
21:15  0                                  cloud to h 5, patches near top
21:30  0                                  cloud to h 5
21:45  0                                  cloud to h 10
22:00  0                                  cloud to h 10
22:15  X                                  cloud to h ~10
22:30  II          1    7            ~10  cloud to h ~5, lightbox
22:45  II,IV       2    8      <340  ~10  cloud to h ~3, some higher, lightbox
23:00  II,IV       3    8      <330  ~15  cloud to h 3-8, lightbox
23:15  II,IV       3    8      <335  ~15  cloud to h 3, to h 8 on left, lightbox
23:30  II          2    9                 cloud to h 3, to h 8 on left, lightbox
23:45  NLC                                low, through cloud, lightbox
00:00  NLC                                low, through cloud, lightbox
00:15  NLC                                low, through cloud, lightbox
00:30  NLC                                low, through cloud, lightbox
00:45  II          2    7                 through cloud, clear above
01:00  II          2    7                 through cloud, clear above
01:15  I,II        2    7                 through cloud, clear above
01:30  I,II        2   10      <350  >15  cloud to h 5
01:45  I,III       2   12      ~350  >15  cloud to h 6
02:00  NLC         1   15       350  >15  cloud to h 7, patches at h 13
02:15  III         1   25  20     5   10  cloud to h 7 or 10, patches to h 15
02:30  III         1   20  18     0    7  cloud to h 10, on left to h 15
02:45  0                                  cloud patches to h 20
03:00  0                                  cloud patches to h 20
03:15  0                                  cloud patches to h 20

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: Stichill
Date: 2010/07/16-17
Start: 22:30
End: 02:30
Forms: I,II,III,IV
Max elevation: 25
Max brightness: 3
Comments:
<a href="http://www.chiandh.me.uk/p/NLC_2010-07-16/17">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  2.000 335.1  -9.9  -1.8  40.8  0-255 q31840.jpg m31840.jpg
22:45  4.000 338.5 -10.7  -2.4  22.6  0-255 q31844.jpg m31844.jpg
23:00  4.000 342.0 -11.4  -2.8  15.7  0-255 q31848.jpg m31848.jpg
23:15 13.000 345.5 -12.0  -3.2  12.1  0-255 q31855.jpg m31855.jpg
23:30 15.000 349.1 -12.5  -3.5  10.1  0-255 q31861.jpg m31861.jpg
23:45 15.000 352.6 -12.8  -3.7   8.9  0-255 q31867.jpg m31867.jpg
00:00 15.000 356.2 -13.0  -3.8   8.2  0-255 q31873.jpg m31873.jpg
00:15 15.000 359.8 -13.1  -3.9   8.0  0-255 q31879.jpg m31879.jpg
00:30 15.000   3.4 -13.0  -3.8   8.2  0-255 q31885.jpg m31885.jpg
00:45 30.000   7.0 -12.9  -3.7   8.8  0-255 q31892.jpg m31892.jpg
01:00 15.000  10.5 -12.5  -3.5   9.9  0-255 q31897.jpg m31897.jpg
01:15 13.000  14.1 -12.1  -3.3  11.8  0-255 q31903.jpg m31903.jpg
01:30  8.000  17.6 -11.5  -2.9  15.0  0-255 q31908.jpg m31908.jpg
01:45  4.000  21.1 -10.8  -2.5  21.3  0-255 q31912.jpg m31912.jpg
02:00  2.000  24.6 -10.0  -1.9  36.8  0-255 q31915.jpg m31915.jpg
02:15  2.000  28.0  -9.1  -1.2  89.3  0-255 q31918.jpg m31918.jpg
02:30  0.800  31.3  -8.0  -0.4 145.8  0-255 q31920.jpg m31920.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).