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AURORA Section, Bulletin No.3                                                         -2-


                                 OBSERVING THE AURORA

New observers should gain experience by searching the sky for aurora whenever taking part
in outdoor astronomical observing. Presence or absence of aurora, area of the sky
covered, brightness, and colour, will form the basis of your initial reports. The torus
of aurora can be classified with more experience. Eventually, the elevations of the
forms of aurora in the sky can be measured along the magnetic meridian.

For recording aurora, the sky has been divided into four quadrants. The most important
quadrant for your observations is the one centred on your north and extending from NW to
NE at the horizon up to the zenith (Figure 2). Each quadrant has been divided into
three zones, frau 0 to 30° elevation, 30° to 60°, and fran 60° to the zenith. In
reporting, you should note the quadrant and zones containing glows, lower borders of arcs
and ends of isolated rays ù An illustration of this procedure is shown in figures 1 and 2.


TIME OF OBSERVATION

Observations should be made approximately on the hour whenever no aurora is in the sky or
whenever only quiet forms such as the glow or a faint homogeneous arc are present. How-
ever, when an arc begins to show sane signs of becoming active (greatly increased bright-
ness or the appearance of motion or rays) the display should then be observed half hourly.

It is important that observations be collected from many locations to chart completely
the course of an auroral display. Thus a single report of the presence or absence of
aurora from Winnipeg may fill a gap left by a Regina observer not able to make an
observation. Even if you can not report regularly, your occasional reports will be
most helpful. Contribute as much data on the report form as your experience allows.
If a report originating in London states that aurora occurred low in the north between
20 hours (8 PM) and 23 hours (11 PM) on March 10/11, 1965, this may confirm another ob-
servation from north Toronto where sane uncertainty existed about the observation.

Upon request, the Auroral Centre, National Research Council, Ottawa 2, Ontario, will
forward to interested observers a supply of report forms, mailing envelopes and a complete
set of observing instructions.

I am anxious to contact representatives of local Centres concerning the accumulation of
duplicate copies of visual aurora reports so that an independent R.A.S.C. survey can be
made over the next eleven-year sun-spot cycle.





                                                        Earl Milton, National Co-ordinator,
                                                        Aurora Section,
                                                        2 Spence Street, Apt. 12,
September 1965.                                         REGINA, Saskatchewan.