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Re: (meteorobs) CCD image of meteor trail
I would be very interested in seeing your Gif
and I assure you it will not be passed on or displayed
Regards Clive
In message <Pine.OSF.3.91.980416180801.7462D-100000@ast.star.rl.acdot uk>,
Malcolm Currie <mjc@astro1.bnsc.rl.acdot uk> writes
>I have a CCD frame which has a meteor-like trail. It was taken with
>the Nordic Optical Telescope 2.56m on La Palma using a 2048*2048 CCD
>last year. The meteor was a nuisance at the time because it passed
>unerringly through the centre of my target galaxy image, a dwarf(!) in
>the Virgo cluster.
>
>I believe that is it a meteor, rather than a satellite for a number of
>reasons, although the evidence is far from conclusive.
>
>1) The latitude was low and it was an hour before twilight began. The
>skies go from daylight to darkness very quickly at lower latitudes and
>you see far fewer satellites than from the UK.
>
>2) Also studying the image carefully shows that it was tumbling every
>14 arcseconds---the trail has a corkscrew-like ripple. Given a
>typical angular speed of a satellite (well typical of the ones I see
>when telescopic observing) of 15 arcmin/sec, that gives a tumble
>frequency around 60Hz. Yes the putative satellite could be out of
>control or some space junk.
>
>There aren't many arcsecond-resolution images of meteor trails to look
>at. Tumbling might be quite common; rippled meteor trains have been
>seen. Given the 14 large CCD mosaics in use or under development on
>big telescopes, I expect that many more meteors will be captured. If
>the data are archived and well documented, we might be able to glean
>information on faint meteors from such images.
>
>3) There is a hint of some diffuse emission around the trail,
>indicative of a train. The field of view is only 6.2 arcmin, so
>looking for a variation of the wavelength of the ripples across the
>field isn't likely to help discriminate.
>
>From the point of view of publicity material it might as well be a
>meteor.
>
>
>I won't post the GIF file because it's about 200k. E-mail me if you
>are seriously interested to see it soon; it will eventually appear on
>the IMO Web pages... I could produce a smaller cropped version if
>there's a demand. I'm reluctant to place it on anon-ftp, as I've been
>saving the image to promote telescopic-meteor observing. Some
>magazines demand virgin images. Does the Web count?
>
>Malcolm
--
Clive A. CHurchward - Dash Xpress Limited
PO Box 143, Altrincham, Cheshire, WA14 5PR, United Kingdom
http://www.dashxdot demon.codot uk
tel: +44 161 941 6277 - fax: +44 161 941 7383
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