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NLC 2010-05-25/26

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: 2010-05-25/26

  UT   forms  bright   height   azimuth   comments
               ness   top bot  left rght  e.g. weather
-----  -----  ------  --- ---  ---- ----  --------------------------------
21:15  0                                  clear
21:30  0                                  thin cirrus to h 4
21:45  0                                  thin cirrus to h 4
22:00  0                                  thin cirrus to h 10
22:15  0                                  thin cirrus to h 10, cumulus on left
22:30  X                                  cloud patches left and top
22:45  X                                  cloud patches, except bottom right
23:00  X                                  cloud patches, except bottom right
23:15  X                                  cloud patches, except bottom right
23:30  X                                  cloud patches, fake NLC at h 30, moonlit?
23:45  X                                  cloud patches all over
00:00  X                                  almost overcast
00:15  X                                  almost overcast
00:30  X                                  almost overcast
00:45  X                                  almost overcast
01:00  X                                  almost overcast
01:15  X                                  overcast
01:30  X                                  overcast
01:45  X                                  overcast
02:00  X                                  overcast
02:15  X                                  overcast
02:30  X                                  overcast
02:45  X                                  almost overcast
03:00  X                                  almost overcast

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: 2010/05/25-26
Start: 21:15
End: 22:15


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)
----- ------ ----- ----- ----- -----  ----- -------------------------
23:30 30.000 351.2 -12.9  -3.7   8.7  0-255 q28523.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).