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NLC 2009-07-02/03

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 5 min
Date: 2009-07-02/03

  UT   forms  bright   height   azimuth   comments
               ness   top bot  left rght  e.g. weather
-----  -----  ------  -------  ---- ----  --------------------------------
21:45  X                                  cirrus
22:00  X                                  cirrus
22:15  X                                  cirrus
22:30  X                                  cirrus
22:45  X                                  cirrus
23:00  X                                  cirrus
23:15  III?      1     25  15   340    5  cirrus below and both sides
23:30  X                                  cirrus to h 15
23:45  X                                  cirrus to h 10
00:00  X                                  cirrus to h 10
00:15  II        2     15                 amongst cirrus
00:30  IV        2     15      <325  355  amongst cirrus
00:45  IV        2     15      <325    0  also cirrus
01:00  IV        2     15      <325    0  also cirrus
01:15  II        3     20      <325  350  also cirrus
01:30  IV        3     25      <325   10  also cirrus
01:45  IV        2     25      <325   25  cirrus below
02:00  IV        1     30      <325   25  cirrus below
02:15  0                                  cirrus to h 10
02:30  0                                  cirrus to h 10
02:45  0                                  cirrus 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: 2009/07/02-03
Start: 00:15
End: 02:00
Forms: II,IV
Max elevation: 30
Max brightness: 3
Comments:
<a href="http://www.chiandh.me.uk/p/NLC_2009-07-02/03>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  8.000 345.5 -10.0  -1.9  36.1  0-255 q04703.jpg m04703.jpg
00:15 20.000 359.5 -11.1  -2.6  18.2  0-255 q04748.jpg
00:30 20.000   3.1 -11.1  -2.6  18.6  0-255 q04760.jpg
00:45 15.000   6.6 -10.9  -2.5  20.4  0-255 q04772.jpg
01:00 15.000  10.1 -10.6  -2.3  24.3  0-255 q04784.jpg
01:15 10.000  13.6 -10.2  -2.0  32.4  0-255 q04795.jpg
01:30  6.000  17.0  -9.6  -1.6  52.2  0-255 q04804.jpg
01:45  3.200  20.4  -8.9  -1.1  99.6  0-255 q04811.jpg
02:00  2.000  23.8  -8.1  -0.5 142.3  0-255 q04815.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).