
NLC 2009-07-24/25
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 dSLR with limited field of view A ~325-35, h ~0-40 images every 5 min Date: 2009-07-24/25 UT forms bright height azimuth comments ness top bot left rght e.g. weather ----- ----- ------ --- --- ---- ---- -------------------------------- 21:15 X cloud 21:30 X cloud 21:45 X cloud 22:00 X cloud 22:15 X cloud 22:30 X cloud 22:45 X cloud 23:00 X cloud 23:15 X cloud 23:30 X cloud 23:45 X cloud 00:00 X cloud 00:15 X cloud 00:30 X cloud 00:45 X cloud 01:00 NLC? through small cloud gap 01:15 X cloud 01:30 NLC? through cloud gap 01:45 NLC? through cloud gaps 02:00 NLC? through cloud gaps 02:15 I,III 4 5 cloud in front 02:30 NLC 3 5 cloud on right 02:45 NLC 2 5 cloud on right 03:00 0 low cloud on right 03:15 0 low cloud on right 03:30 0 low cloud on right 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: 2009/07/24-25 Start: 01:00 End: 02:45 Forms: I,III Max elevation: 5 Max brightness: 4 Comments: <a href="http://www.chiandh.me.uk/p/NLC_2009-07-24/25>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 ----- ------ ----- ----- ----- ----- ----- ------------ 01:00 25.000 9.9 -13.9 -4.3 5.9 0-150 q09515.jpg 01:30 25.000 17.1 -13.0 -3.8 8.5 0-200 q09545.jpg 01:45 25.000 20.6 -12.3 -3.4 10.9 0-255 q09560.jpg 02:00 25.000 24.1 -11.5 -2.9 15.3 0-255 q09575.jpg 02:15 8.000 27.6 -10.6 -2.3 24.6 0-255 q09590.jpg 02:30 4.000 31.0 -9.5 -1.6 55.6 0-255 q09600.jpg 02:45 2.500 34.4 -8.4 -0.7 132.3 0-255 q09606.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).