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Observation by Derek Robson: Bright meteor and spectrum 6 Aug 2019 00...

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Derek Robson


Derek Robson


2019 Aug 05 - 23:58


2019 Aug 09 - 19:06



Planetarium overlay



Field centre

RA: 13h49m
Dec: -28°24'
Position angle: -179°05'

Field size

0°06' × 0°04'

  • Watec 902H2S video and diffraction grating (500 lines/mm)


Target name



Bright meteor and spectrum 6 Aug 2019 00:58:19.3 UT

About this image

Meteor and spectrum recorded on video.  A frame was extracted using UA software, then the spectral part was attempted to be enhanced by adjusting brightness, contrast and gamma in Irfanview.  The spectrum was obtained by taping a polymer sheet type diffraction (500 lines/mm) across the front of the CCTV box window. There is an air space between the CCTV glass window/grating, which is exposed to the elements.  After a few weeks of use, the grating doesn't appear to have changed visibly other than a very slight bend outward.  The set up has produced some interesting spectra of aircraft, the moon and a faint spectrum of the ISS.

The meteor spectrum shows several characteristic diffraction lines from certain elements, identified and annotated by Bill Ward; and Richard Bassom.  Camera made up, supplied and tested by William Stewart.  Diffraction grating supplied by Edmund Optics, UK.  Meteor magnitude was estimated by UA software at approx - 4 (minus 4). But the grating will have attenuated the brightness somewhat and the actual magnitude is thought to be brighter than - 4.

I intend to load the spectral image into BASS to produce a digital spectrum. However I am new to the software, and unsure how to calibrate the wavelength axis (neon spectrum on the same equipment not available; even bright stars available are not sufficiently bright enough to produce spectra).  The fact that aircraft have produced some spectra, I wondered if some sense check type calibration could be done providing the lights used on aircraft were known [there is a clear difference in spectra between the main different alternating flashing lights, presumably headlamps and landing lights].

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