IMAGING FOR SCIENCE PART 3: METEORS
Pete Lawrence explains how a handful of images can give you an idea of a meteor’s speed, overall shower activity and more
You can glean a great deal from these fleeting flashes in the sky – from speed to composition.
Meteors are one of the most accessible aspects of the night sky, yet on top of their undoubted splendour there’s much valuable scientific analysis that amateurs can get stuck into. The core element of meteor analysis is statistical recording. Date and time stamps on images are important to identify when a meteor trail occurred. To do this, synchronise a camera’s clock with a reliable time source, like an online atomic clock. It’s also recommended that you use UT. Trail timing can only be determined to the accuracy of the exposure start time plus the exposure length. A continuous record of conditions is also important as variations in factors such as sky transparency have notable effects on rates.
Most digital cameras store their settings in an EXIF (Exchangeable Image File Format) file header written into each image. However, if you’re using manual lenses add a description of the lens and its settings as this information isn’t normally included in the EXIF header.
Many video and high frame rate camera control programs also provide logging options to record the copious setting variants that can be applied. Finally, make a note of the centre of the sky area being photographed in RA and dec. Hardware & Software HARDWARE DSLR, CCD camera, high frame rate camera, video astro camera, mid- to wide-angle lenses
SOFTWARE Image viewer such as FastStone (www.faststone.org/FSViewerDetail.htm) Photoshop or Gimp (www.gimp.org) UFOCapture, UFOAnalyzer, UFOOrbit (sonotaco.com/soft/e_index.html) MetRec (www.metrec.org)
Many digital cameras save images with an EXIF header (inset), containing all the vital info about the settings used
ABOUT THE WRITER Pete Lawrence is an expert astronomer and astrophotographer who holds a particular interest in digital imaging