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NLC 2009-07-03/04

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: 2009-07-03/04

  UT   forms  bright   height   azimuth   comments
               ness   top bot  left rght  e.g. weather
-----  -----  ------  -------  ---- ----  --------------------------------
21:45                                     cloud
22:00                                     cloud
22:15                                     cloud
22:30                                     cloud
22:45  II,III    1     30                 cloud below and on right
23:00  II,IV     2     30                 cloud below and on right
23:15  II,IV     2     25                 cloud below and on right
23:30  II,III,IV 2     20                 cloud below
23:45  II,III    2     20                 cloud below
00:00  III       2     15                 cloud below and on right
00:15  II,III    3     20   0             cloud below
00:30  II,IV     3     20   0             cloud on right to h 5
00:45  II,IV     3     20   0             cloud on right to h 5
01:00  II,IV     3     15   0             clear
01:15  II,IV     3     15   0             clear
01:30  II,IV     3     15   0             clear
01:45  II,IV     3     25   0             clear
02:00  IV        3     35                 clear
02:15  IV        2     40                 clear
02:30  0                                  clear
02:45  0                                  clear

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: 2009/07/03-04
Start: 22:45
End: 02:15
Forms: II,III,IV
Max elevation: 35
Max brightness: 3
Comments:
<a href="http://www.chiandh.me.uk/p/NLC_2009-07-03/04>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)
----- ------ ----- ----- ----- -----  ----- ---------------------
22:45  3.200 338.6  -8.8  -1.0 109.5  0-255 q04841.jpg m04841.jpg
23:00  6.000 342.0  -9.5  -1.6  57.4  0-255 q04847.jpg
23:15 10.000 345.5 -10.1  -2.0  34.0  0-255 q04856.jpg
23:30  8.000 349.0 -10.6  -2.3  24.7  0-200 q04867.jpg
23:45  8.000 352.5 -10.9  -2.5  20.3  0-150 q04879.jpg
00:00  8.000 356.0 -11.1  -2.6  18.2  0-150 q04891.jpg
00:15 15.000 359.5 -11.2  -2.7  17.4  0-255 q04904.jpg
00:30  8.000   3.0 -11.2  -2.7  17.8  0-150 q04919.jpg
00:45  8.000   6.5 -11.0  -2.6  19.5  0-200 q04931.jpg
01:00  8.000  10.0 -10.7  -2.4  23.1  0-255 q04943.jpg
01:15  4.000  13.5 -10.2  -2.1  30.4  0-150 q04955.jpg
01:30  4.000  17.0  -9.7  -1.7  47.9  0-255 q04964.jpg
01:45  2.000  20.4  -9.0  -1.2  92.5  0-255 q04972.jpg
02:00  2.000  23.8  -8.2  -0.6 139.2  0-255 q04976.jpg
02:15  1.000  27.2  -7.3   0.3 158.3  0-255 q04979.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).