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First and foremost, this is an activity that any amateur
astronomer can manage. Even your relatives or friends without any
experience in star gazing can join in, provided you have given them
sufficient guidance. The more observers we have, the more data can be
collected.
The purpose of this observation is to count the number of
visible meteors that belonged to a given meteor shower and those that do
not belong to this group. First, identify the constellation where the
radiant lies. Watch carefully the path of the meteors. If necessary, you
can trace back the path as an imaginary straight line to see whether it
intersects with the radiant. If so, the meteor is a shower meteor,
otherwise it is a sporadic Record the number of meteors visible per hour,
both for the shower meteors and the sporadic meteors.
This is a very simple observation. Plotting the meteors'
paths on star maps, which calls for more skills and experience in
observing meteors, is generally not required.
To foster more
accurate observations of higher scientific value, some equipment is
necessary. A reclining lawn chair or a straw mat with a pillow make you
feel more comfortable. Remember, comfort is essential for good
observations. Do not sit and hold your neck upright as this gesture
strains the blood circulation in your neck and thus reduces your eyesight.
A faint flashlight or a dim red torch helps you write in the dark. A
pencil and a sheet of paper is essential for recording the number of
meteors as well as the starting and ending time of observation. Remember
to bring a watch along with you. Avoid using roller pens. A roller pen
does not write well when you are lying down with the pen pointing upwards.
Keep the duration
of each observational interval at one hour . You should not observe for
more than four hours during any one night, since the accuracy of your data
will reduce when fatigue takes hold. To keep you alert and efficient, take
a break and consume some food. Warm clothing is necessary to keep your
body warm. If you go in pairs or in groups, keep you and your partners
apart. Do not exchange your views, since this may introduce unwanted
errors into your observation (for instance, the same meteor may be
recorded twice as two different meteors). In addition, each person should
look at a different part of the sky.
The limiting
magnitude must be entered on the data sheet. Below is a table listing the
magnitudes of the major stars in the constellation Ursa Minor.
Experienced
amateurs can do a lot more. This includes recording the meteors' paths and
their lengths, the magnitudes, colours, the presence of trains and their
durations, etc. Observers can work in pairs. One carries out the
observation with a star-map and a pen and the other records with a record
sheet and a piece of watch. When one sees a meteor, he should say
¡¥yes¡¦ and plot the meteor's path on the star-map. He should then tell
his partner the magnitude, duration, colour, whether the meteor has
exploded or has a persistent train. On hearing 'yes', his partner should
put down the time along with all those information that is passed to him.
Do not forget to label the meteor¡¦s path. Responsibilities of the two
should be clear-cut. Personal judgment should be avoided at all costs.
While a binocular is helpful to the observation of a meteor train, a
cassette recorder can record what has been said about the phenomenon.
A report with
qualitative or quantitative conclusions like the following is always
welcome: 'The majority of the meteors had exploded', or '40% (+/- 5%) of
the meteors are dark red in colour', etc.. A meteor shower becomes a
meteor storm when the meteors' hourly rate reaches several hundreds per
hour. At this time, you can shorten the time of observation to 5 or 10
minutes, while the region of the sky being monitored can be reduced. These
changes should also be specified on the record sheet.
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