[Prev][Next][Index][Thread]
(meteorobs) Re: Newcomer with meteor observing questions
A recent subscriber who has been watching shooting stars off an on for
years had a few questions about the IMO meteor recording method that we
have mentioned here on the list. I suggested that we address all these
questions on the 'meteorobs' list, since I think that many of our newer
subscribers probably have very similar questions of their own!
>I am an extremely keen meteor observer, however I am not skilled in the
>[IMO data recording method]. I am interested to learn this so that I may
>record data in a manner that may be useful to [professional researchers].
>I would very greatly appreciate any information or websites that would
>enable me to do this.
The best starting point I can suggest for newly interested meteor observers
is the North American Meteor Network's "Guide to Meteor Showers and Their
Observation". This fine "beginner's guide" is available on the Web at:
http://Web.InfoAvedot net/~meteorobs/guide.html
You'll also find some handy materials there to take out in the field with
you, that should help you get started recording. If you want more details
about the IMO method and the science behind it, try this site:
http://www.imodot net/visual
Finally, for yet more high quality background material on our dual hobby
and amateur scientific endeavor, definitely check out the American Meteor
Society's Web pages, including the following:
http://www.amsmeteors.org/showers.html
http://www.amsmeteors.org/mcleod/mcleod1.html
>How do you convert to Universal Time and how are the days in different
>time zones/regions affected
Universal Time is basically just "Greenwich Mean Time" or "Zulu Time".
(There are differences among all three, but ignore these for now.) So
if you are on the US East Coast, and it is still Daylight Savings Time
(as it is right now), you would add 4 hours to get UT. But from Syndey,
Australia right now, you would SUBTRACT 10 hours to get UT. Note that
this DOES affect the date: if it is 9am on October 25 in Sydney, it is
actually 23:00 on October 24 in Universal Time, and 19:00 Eastern Day-
light. Note also that some of us try to avoid confusion around dates by
noting dates on meteor reports in LOCAL time (with both the night's AND
the following morning's dates separated by a "/" slash), while we noted
time in UT. Thus if I were to start an observing session right now, I'd
note the date and time as "23:38 UT, 24/25 October 2000".
This works for me - perhaps others who observe from the Pacific Islands,
Australia or Asia can relate how they report THEIR dates, too?
>4. What is meant by magnitude?
One of the most scientifically important things we can note as amateur
meteor observers, is how BRIGHT a meteor appears: this brightness is
measured on the same (reverse logarithmic) scale that star brightness
is measured on, the "magnitude" scale. The faintest star most people
will see while observing in a dark sky is somewhere near magnitude 6.
The brightest star in the sky, Sirius, in the constellation of Canis
Major, is magnitude -1.5 (a lower number, since Sirius is BRIGHTER.)
The Full Moon is actually about magnitude -12.5!
We record the magnitudes of meteors simply by memorizing magnitudes of
several "comparison stars" while observing, and comparing the meteor's
brightness to our comparison stars as soon as we see it flash by in
the sky. Then we record each estimated magnitude on our report forms.
I hope this helps rather than confuses folks. If it only spurs yet MORE
questions about meteor observing, then I succeeded in my goal! Please
don't ever be shy about asking these further questions, either privately
or on our 'meteorobs' list: that's what we're here for.
Clear skies,
Lew Gramer <owner-meteorobs@jovian.com>
To UNSUBSCRIBE from the 'meteorobs' email list, use the Web form at:
http://www.tiacdot net/users/lewkaren/meteorobs/subscribe.html
Follow-Ups: