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NLC 2017-06-24/25

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 compact camera with limited field of view
          A ~325-35, h ~0-40; images every 15 min
Date: 2017-06-24/25

   UT     forms  bright   height   azimuth   comments
                  ness   top bot  left rght  e.g. weather
--------  -----  ------  --- ---  ---- ----  --------------------------------
21:45:01  X                                  widespread cloud
22:00:05  X                                  cloud to h 15
22:15:06  X                                  widespread cloud
22:30:08  X                                  almost overcast
22:45:10  X                                  almost overcast
23:00:10  X                                  almost overcast
23:15:10  X                                  almost overcast
23:30:09  X                                  almost overcast
23:45:19  II         2     3                 almost overcast
00:00:19  II         2     3                 almost overcast
00:15:18  II         2     3                 widespread cloud patches
00:30:19  X                                  cloud above h 15
00:45:19  X                                  cloud above h 15
01:00:09  X                                  cloud above h 15
01:15:03  0                                  cloud patches above h 30
01:30:02  0                                  few cloud patches
01:45:03  0                                  cloud above h 15 or 25
02:00:02  X                                  cloud above h 15
02:15:02  0                                  almost clear
02:30:01  0                                  almost clear
02:45:01  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: 2017/06/24-25
Start: 23:45
End: 00:15
Forms: II
Max elevation: 3
Max brightness: 2
Comments: Almost overcast.
http://www.chiandh.eu/nlccam/20170624-25.shtml

forms: I: veil
       II: bands
       III: waves
       IV: whirls
       NLC: 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)
-------- ------ ----- ----- ----- -----  ----- -------------------
23:45:19  4.000 353.0 -10.4  -2.2  26.8  0-255 q1447.jpg m1447.jpg
00:00:19  4.000 356.5 -10.6  -2.3  23.7  0-255 q1451.jpg m1451.jpg
00:15:18  4.000 360.0 -10.7  -2.4  22.8  0-255 q1455.jpg m1455.jpg

exp: Exposure time in seconds (200 ISO, f/2.8).
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).