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                      THE ROYAL ASTRONOMICAL SOCIETY OF CANADA

                   STANDING COMMITTEE ON OBSERVATIONAL ACTIVITIES

LUNAR SECTION                                                          BULLETIN NO.5


Announcement

    Upon the recent retirement of the Lunar Co-ordinator, Mr. R.R. Thompson, President
of the Toronto Centre, the writer was asked by Mr. Vent Ramsay, as Chairman of the
National Committee on Observational Activities, to assume this position.


LUNAR ECLIPSE, JUNE 24th, 1964

	The first lunar eclipse since the very dark eclipse of December 
30th, 1963, has
aroused considerable interest among lunar observers, particularly 
those wishing to
ccnpare these two eclipses with the two very dark total lunar 
eclipses of 1913.

    Unfortunately for observers in Centres west of Windsor, Ontario, totality will be
over when the moon has risen, a few minutes before sunset.

The following is a list of the nine Centres with contacts in each which are pre-
sently cooperating with the National Committee on Lunar Observing; moonrise and sun-
set times are provided in Universal Time (U.T.) for Wednesday, June 24th, 1964:

              Centre          Contact           Moonrise            Sunset

            Halifax         W. L. Orr            00  00             00  04
            Quebec          Pierre Houde         00  38             00  44
            Montreal        George Wedge         00  44             00  49
            Ottawa          W. M. Cameron        00  49             00  53
            Kingston        Raymond Burns        00  48             00  52
            Niagara Falls   Frank Campbell       00  55             00  59
            Toronto         Archie Ostrander     01  00             01  04
            Hamilton        J. G. Craig          00  59             01  03
            Edmonton        William Cable        04  06             04  10

                                                                                U.T.
                                                                               h.  m.
                                                 Moon enters penumbra          21  58
                                                 Moon enters umbra (1st con.)  23  09
                                                 Totality begins   (2nd con.)   0  16
       (Diagram here.)                           Middle of eclipse              1  06
                                                 Totality ends     (3rd con.)   1  57
                                                 Moon leaves umbra (4th con.)   3  03
                                                 Moon leaves penumbra           4  14

    While Halifax is the only Centre which can observe 2nd contact, valuable contribu-
tions can be made by other Centres should they wish to carry out one or more of the
following programmes.

Crater Timing

    One of the maze important aspects of this event will be the timing of the passage
of the moon through the earth's shadow. It is recommended that a small team (2 to 3
persons) be organised to time the immersion and emersion of specific craters into, and
out of, the shadow as it crosses the face of the moon. Timing is best accomplished
by radio time signals (CHU Ottawa, 3.330 K.C.). If these are simultaneously recorded
on tape, along with the observer's verbal estimate, a very accurate time determination
is provided, as well as a permanent record. As the official record of these events
consists of the reports of those specifically responsible for timing, it is best to
station them at considerable distance from the others participating. In deciphering
a tape, much confusion can result when the record contains unwanted contributions from
several, people in addition to the comments of the appointed observers.

-2-


    Fifteen craters recommended for this project are , from east to west Grinaldi,
Aristarchus, Kepler, Copernicus, Pytheas (bright), Tinocharis, Tycho, Plato,
Aristotelos, Eudoxus, Menelaus, Plinius, Taruntius, a bright ring arid Proclus.

Colour and Intensity Observations

    The colour of the eclipsed moon, and also the degree of darkness of the eclipse,
vary from one eclipse to another and depend in part upon conditions in the earth's 
atmosphere where refraction of the light from the sun into the earth's shadow takes
place.

    Descriptions of the moon's colour vary with each observer, colour being subjective;
therefore, observers are requested to use the tens in the accompanying Danjon Scale
unless the colour as seen differs completely with the Scale.  In this case, the ob-
server should describe it in his own Words.

    It will be seen that the Danjan Scale is also applicable to the darkness of the
eclipse and wifl be used in conjunction with Fisher's Scale, which measures only the
degree of darkness. Observers are requested to familiarize themselves with each
scale, and to use this terminology when reporting.

It is important that the time of the observation be recorded as well as information
about any optical aid employed.

DANJON SCALE:

    (0)  Very dark eclipse, moon almost invisible, especially mid-eclipse;
    (1)  Dark eclipse, gray Or brownish oolouration, detail very vague;
    (2)  Deep red or rust colour, very dark central area, outer edge relatively bright;
    (3)  Brick red eclipse, usually with a bright Or yellow shadow rim;
    (4)  Very bright copper red or orange eclipse with bluish, bright shadow edge.

FISHER'S SCALE:

    (0)  6" telescope or larger needed to see "seas" and principal craters.
    (1)  2" or 3" aperture required for major detail.
    (2)  Naked eye only needed to see principal details.

    The appearance of the shadow edge may not correspond with the general eclipse
colour as outlined in the Danjon Scale. A notation should be made if this occurs and
any unusual shape exhibited by the shadow edge should be noted.

    Soon after totality begins, intensity observations should be made and at 10-minute
intervals thereafter until third contact. This should be the responsibility of those
assigned to this observation (assuming a group is organized).

    The enclosed form for recording such data, in addition to the outlined discs which
are to be used to indicate colour boundaries, may be obtained from the writer.


Special Area Observation

    During a total lunar eclipse, the moon's surface is subject to rapid changes in
temperature.  These rapid changes may trigger observable effects in certain areas
which have, on occasion, exhibited transitory changes in appearance which so far are
not explained.  Many such areas have been reported but it is not possible to devote
the necessary study to all of these; hence three easily found craters which are
suitable for most eclipse conditions have been selected. 

    The first is the very bright crater Aristarchus and adjacent area.  Late in 1963,
astronomers at Lowell Observatory reported a redness surrounding this crater which
seemed to change shape from minute to minute. This report was confirmed by a group of
amateurs in Japan which observed a similar phenomenon on December 28th, 1963. This
will be of prime interest in the forthcoming eclipse and should be observed with the
largest aperture available at a magnification not less than 200 times. Close attention
should also be paid to the adjoining crater Herodotus and cleft, all located on the
north-east quadrant of the moon.

                                         -3-

    The crater Pluto, a dark grey, level floored crater, located on the northern edge
of Mare Imbrium, has had several spots and white streaks reported on its floor. The
spots, in some cases, represent craterlets and the streaks, notably two forming a wedge
on the south-west corner, have an obscure origin.

    These spots and streaks are unaccountably invisible at times when the surrounding
landscape is plainly visible. It has been speculated that "mists" or evolution of
gases may cause this phenomenon. Perhaps a rapid temperature change will induce this
effect and it may be detected with the aid of a telescope.

    Another lunar crater of much historical interest is Linne, a small object on the
floor of Mare Serenitatis, lying just west of the opening into Mare Imbrium.  This
diffuse white spot has been reported to change in size during eclipse and a search
should be made for this effect.

    Each area should be studied before, during and after the eclipse in order to see
if any change has taken place.  It is recommended that observing the moon on the
evening before the eclipse will provide the necessary familiarization.

    Seeing conditions nay render invisible the fine detail in Plato and Linne.  All
reports of observation of these objects should include the rated seeing conditions,
type, size and power of optical equipment and, if possible, drawings or sketches of
the area.


LUNAR-METEOR WATCH

    A lunar eclipse affords the best opportunity of observing a meteorite impact on the
moon. If such an impact is observed, it is essential that the exact location, direc-
tion, time and appearance of the flare be noted,  Should the observation be duplicated
at another site, it cart be determined whether the flare is truly a lunar phenomenon or
whether it is of terrestrial origin, seen against the lunar background.

The observer should: (1)  be able to judge the location of principal lunar features
so as to be able to plot a flare or trail on an available map;  (2) in the event of a
flare, call out "FLARE" so that the tine can be recorded automatically;  (3) immediately
plot the location on the map, noting direction and length, if moving;  (4) note
particularly if it is stationary;  (5) estimate duration of flash;  (6) note colour
and estimate brightness.

Theoretical Appearance:

A lunar flash may appear as a faint, slowly moving point of light, ending in a
burst, listing 2 or 3 seconds.  Estimated length of trail - 75 miles or 1/30 of the
moon's diameter. Previous reported sightings (unconfirmed) have been described as:
"small bright flash, lasting 3 seconds, changing from blue-white to greyish yellow
and "bright speck, lasting one second and leaving a glow for perhaps two seconds or
more".

Recommended Equipment:

    Two 6" telescopes of sufficient power to cover the required field, lunar map, light
source, and proximity to time and tape recorder station. Two observers should search
at any one time, for not longer than 15 minutes per watch, then alternating with another
team of two, to maintain a high level of efficiency.

LUNAR ECLIPSE PHOTOGRAPHY: Enclosed with this bulletin is a special supplement con-
sisting of two parts as produced by the Kodak Co. numbered C-20 and M-18, to provide
helpful guidance.


Reports Iron Centres participating in one or more of the above programmes should be
mailed to the writer at the address given below.  All results will then be collated
and a report on the lunar eclipse observations issued to all Centres.


                                                                  Archie L. Ostrander,
                                                             National Lunar Co-ordinator
                                                                  74 Brimorton Drive,
12 June, 1964.                                                    Scarborough, Ont.
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640612 Lunar Section Bulletin #5 (PDF)1.35 MB
Date: 
640612
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Lunar5A
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Lunar Section Bulletin No. 5
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Other Bulletins
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