
NLC 2011-07-27/28
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 15 min Date: 2011-07-27/28 UT forms bright height azimuth comments ness top bot left rght e.g. weather ----- ----- ------ --- --- ---- ---- -------------------------------- 21:00 0 haze to h 5 21:15 0 haze to h 5 21:30 0 haze to h 5 21:45 0 haze to h 8 22:00 0 haze to h 8 22:15 0 22:30 0 22:45 0 23:00 0 23:15 0 23:30 0 23:45 0 00:00 0 00:15 0 00:30 0 00:45 0 01:00 0 01:15 I? 01:30 I 1 5 350 20 01:45 I 2 7 345 >30 02:00 I 2 8 340 >30 02:15 I 2 10 <335 >35 02:30 X haze to h 8, cloud on left 02:45 X widepsread cloud 03:00 0 cloud on left and right 03:15 X widespread cloud 03:30 X widespread cloud 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: 2011/07/27-28 Start: 01:15 End: 02:15 Forms: I Max elevation: 10 Max brightness: 2 Comments: <a href="http://www.chiandh.me.uk/p/NLC_2011-07-27/28">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) ----- ------ ----- ----- ----- ----- ----- --------------------- 01:30 15.000 17.2 -13.5 -4.1 6.9 0-255 q17168.jpg m17168.jpg 01:45 15.000 20.7 -12.8 -3.7 8.9 0-255 q17174.jpg m17174.jpg 02:00 13.000 24.3 -12.0 -3.2 12.1 0-255 q17180.jpg 02:15 5.000 27.8 -11.1 -2.6 18.3 0-255 q17184.jpg m17184.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).