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Re: (meteorobs) Small Format Meteor Spectroscopy

Lew Gramer wrote:

-----Original Message-----
From: Lew Gramer <dedalus@latrade.com>
To: Meteor Observing Mailing List <meteorobs@latrade.com>
Date: November 2, 1998 9:20 AM
Subject: Re: (meteorobs) Small Format Meteor Spectroscopy


>
>Ed, thanks for the encouragement re: meteor spectroscopy! One
>thing all meteor amateurs should keep in mind is that, during
>showers with highly enhanced rates (i.e., storms or substorms),
>even a technique with a very marginal chance of success, e.g.,
>meteor spectroscopy with inexpensive grating and 35mm camera,
>has a real chance of gathering valueable data in one night!
>
>Ed, can I suggest you forward a brief list of Web links and/or
>paper documents which would be valuable for raw beginners who
>are attempting to capture meteor spectra for the first time?
>
>Clear skies!
>Lew Gramer
>


Hello Lew:
    Unfortunately, most of the papers on meteor spectroscopy are scattered
across many professional publications, most of which arn't readily available
to amateurs.  One could check a good university library and scan various
astronomical journals that they may subscribe to.  This won't give you the
basic information that you are looking for, however.
    The techniques used to obtain spectra arn't much different than normal
meteor photography.  One simply mounts a dispersive element, such as a prism
or transmission grating in front of the camera lens.  You must however
attempt to line the prism or grating so the expected flight path of the
meteor is parallel to the thin edge of the prism or parallel to the grating
grooves.  If it is across the grooves or prism, no spectrum will be
measurable as the lines will be dispersed in such a way, that the will
overlap.  The analysis of a spectrum is best left up to professionals with
experiance in this field.  Dr. Jiri Borovicka, at Ondrejov, has indicated
that he would be happy to examine spectra obtained by amateurs and the best
ones would be selected for measurement.  Here is a list of some publications
that the amateur might find useful.

    Amateur Telescope Making - Book Two
    "Meteor Photography"  by Peter M. Millman

    (This paper is a classic, by the late pioneer of meteor spectroscopy,
    Peter Millman.  It describes objective prism spectroscopy but the
    same principles apply if you use an objective grating.)

    Journal of the Royal Astronomical Society of Canada Vol. 52 No.4
    (1958).
    "Meteor Spectroscopy with Transmission Diffraction Gratings -
    by Ian Halliday.  Also published as: Contributions from the Dominion
    Observatory, Vol. 2, No. 27.

    Journal of the RASC (see above) Vol.92 No. 2, April 1998
    "Research note:  Meteor Spectroscopy with Inexpensive Holographic
    Gratings,  by  Ed Majden

One of my prism spectra may be posted to David Balam's, Space Guard Canada
home page.  I will let you know if this occurs.  Some of our all-sky camera
images are posted there at:

        http://astrowww.phys.uvicdot ca/~balam/emo.html

    If anyone has any specific questions, please email me or post the
question to meteorobs.  I will do my best to answer them, and if I can't ,
I'll try and find someone who can.  We would very much like to get more
amateurs interested in Meteor Spectroscopy.  Due to the nature of meteor
photography an amateur may indeed come up with the best spectrum yet.  Using
similar equipment, your chances are just as good as that of a professional.
By the way, Ian Halliday from NRCC and a group in Japan recorded around 60
spectra from the last Leonid meteor storm.  Peter Millman recorded 21
spectra from the Giacobinid/Draconid storm in 1946.

Ed Majden
AMS Meteor Spectroscopy Coordinator