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NLC 2010-05-30/31

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: 2010-05-30/31

  UT   forms  bright   height   azimuth   comments
               ness   top bot  left rght  e.g. weather
-----  -----  ------  --- ---  ---- ----  --------------------------------
21:15  0                                  clear, cirrus on bottom left
21:30  0                                  clear, some cirrus
21:45  0                                  clear, some cirrus
22:00  0                                  clear, cirrus on top right, fake NLC
22:15  0                                  clear, tiny cloud patches
22:30  0                                  cloud to h 5, fake NLC on left
22:45  0                                  cloud to h 7, fake NLC to h 35
23:00  0                                  cloud to h 10, fake NLC to h 30
23:15  0                                  cloud to h 10, fake NLC h 25-30
23:30  X                                  cloud to h 18
23:45  X                                  cloud to h 10
00:00  0                                  clear, cloud to h 4
00:15  0                                  clear, cloud to h 4
00:30  0                                  clear
00:45  0                                  clear
01:00  0                                  clear, cloud to h 8
01:15  0                                  clear, cloud to h 10
01:30  0                                  clear, thin cirrus to h 10
01:45  0                                  clear, thin cirrus to h 15
02:00  0                                  clear, cloud patch near centre
02:15  0                                  clear, cloud patch on right
02:30  0                                  clear
02:45  0                                  clear
03:00  0                                  clear, few cloud patches

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 main periods of absence of NLC are reported to the NLC Observers' Home Page:

Name: Horst Meyerdierks
Country: Scotland
Location: Stichill
Date: 2010/05/30-31
Start: 21:15
End: 03:00
Comments: NLC sector obscured by cloud 23:30 to 23:45.

Images

Listed below are the images with sightings of fake 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)
----- ------ ----- ----- ----- -----  ----- -------------------------
22:00  0.800 330.4  -7.9  -0.3 148.4  0-255 q28920.jpg
22:30  4.000 337.2  -9.8  -1.8  44.3  0-255 q28924.jpg
22:45  6.000 340.6 -10.5  -2.3  25.0  0-255 q28928.jpg
23:00 10.000 344.1 -11.2  -2.7  17.6  0-255 q28932.jpg
23:15 15.000 347.6 -11.7  -3.0  13.9  0-255 q28937.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).