9th March 2012
An X-5 class flare erupted on the Sun from sunspot group AR1429 on the 7th March sending a cloud of charged particles towards the Earth. It seemed it was going to be a glancing blow, but the planetary K-index reached 7 (storm) on the night of the 9th March (Melbourne time) and Bz turned substantially south. Favourable conditions indeed for aurora, but would the auroral oval extend sufficiently north to reach Melbourne, would the weather hold up and would the scattered light from the full moon brighten the sky too much were questions I was asking myself. No better way to find out than go out and have a look a short drive along Port Phillip Bay!
As twilight faded a bank of cloud moved in from the south hiding any obvious auroral glows and projecting beams in that direction. Nevertheless I began taking photos from the time a 15sec exposure gave a mid-tone sky brightness. Close examination of the camera's screen gave a suggestion of developing coloured structures in the sky before they became covered by cloud.
Loading the images onto the
computer and doing a minimal amount of stretching confirmed some reddish
structures to about 40° elevation due south and
greenish glows below the Southern Cross. Roll on solar max!
|20:43 AEDT (09:43UT): hints of red to the right of the Southern Cross and suggestion of greens below are visible to the S through the light-polluted and moon-lit sky. Canon 450D, 14mm lens at f3.2, ISO400, 14sec exposure.|
|20:45 AEDT (09:45UT): two minutes later, the reddish bands have moved southward. Camera details as above.|
|20:47 AEDT (09:47UT): two minutes later, the reddish bands have moved further southward and faded somewhat. Camera details as above.|