DECEMBER 1998
DECEMBER STAR MAP |
INDEX
- 119
DECEMBER 6, 1998: Leonids Wrap Up
- The Leonid Meteor Storm of Tuesday morning, November 17 never materialized, but
rates of many hundreds to perhaps as many as 2000 shooting stars per hour were
recorded by observers in the Canary Islands, west of the African mainland. There
were many bright meteors recorded in Europe, Asia, and the western US prior to the
Canary Island maximum. Some of these shooting stars were as bright as the full
moon which must have been spectacular indeed. As the Earth continued to rotate,
the action shifted eastward over the Atlantic where some professionals are now
saying the true maximum occurred. The favored geographical location, the Far East,
was never in the limelight. While we in the Lehigh Valley were much closer to
ground zero, clouds blanketed the East Coast hiding the show. One report from
Nova Scotia noted over 160 meteors per hour. Fast forward to the present...
On Sunday/Monday mornings, December 13 and 14, we have the opportunity of observing
a more consistent meteor shower called the Geminids. About 30-50 meteors per hour can
be seen radiating from near Castor, the fainter of the two bright head stars of the
Gemini Twins. The night of December 13/14 seems favored, but the 12/13 should also be
good. Observe after midnight viewing high in the south to southwest. Geminid meteors
are rapid and yellowish. Dress warmly, keeping head, hands, and feet toasty.
-
- 120
DECEMBER 13, 1998: Buying Binoculars: Part 1
- If you are contemplating the buying of a telescope as a Christmas gift, consider
binoculars instead. Binoculars offer a wide range of advantages over telescopes,
not the least of which is cost. They are simply cheaper. The person that you’re
buying them for probably doesn’t know much about the sky either. She or he will have
to begin learning the brighter constellations and stars before becoming successful
with a higher powered telescope. Why not help insure that success by beginning the
exploration of the heavens with a highly portable, wide field, low magnification,
easy-to-focus device that makes it fun to locate objects in the sky? You’re also
using two eyes rather than one which produces a more comfortable view. Binoculars
are also multipurpose. Use them anywhere and at anytime, for bird-watching, for
whale-watching, for astronomy. They are also adjustable, meaning that the pupillary
distance between the eyes can be quickly modified to accommodate each person’s
specific pupil-to-pupil distance. If the binoculars are being purchased for
astronomy purposes, consider buying an astronomical field guide, or better yet
a small sky atlas. It will give the recipient a place to start his or her
astronomical pursuits. Purchase binoculars from a reputable camera shop
(434-2313--ask for Tim Miller), not a high volume discount superstore. With
optics, you usually get what you pay for. More about binoculars next week.
To read ahead, check the web site below.
-
- 121
DECEMBER 20, 1998: Buying Binoculars: Part 2
- My column last week dealt with binoculars as a holiday gift. There are a few
finer points I would like to make. For people who are really into astronomy,
optics are a very personal matter. Lack of knowledge often makes it difficult
for the gift giver to make the right choices. If you are really concerned about
insuring maximum satisfaction, you may want the recipient to choose his or her
own binoculars. This becomes almost essential if you wear glasses and cannot
adjust the focus of the binoculars so that you can view images without them.
In order to see the full field of view, binoculars must throw the tightest
bundle of focused light back far enough so that it intercepts the eye. With
glasses, the light bundle may fall short, and the viewer will see a restricted
field. This makes for an uncomfortable and frustrating viewing experience.
Binoculars which are astronomically acceptable should produce a light bundle
which at its smallest diameter is between 5 to 7 millimeters across. To know
this fact take a standard 7x50 binocular. Divide the first number (7) into
the second number (50) and you’ll have your answer. These number designations,
such as 7x35 or 10x50, explain more. The first numeral tells you the
magnification, while the second number states the diameter of the light-gathering
objective in millimeters. There are 25.4 mm per inch. The larger the objective,
the more light the binocular will gather. You’ll see fainter objects. The higher
the magnification, the bigger the observed object will appear. But this will
always be at the expense of a smaller field of view and more noticeable shaking
as you hold your binoculars to view the sky. Lots of decisions...
-
- 122
DECEMBER 27, 1998: Directions From Your Watch
- You’re out hiking and you get lost! You need to find your directions, but
foolishly you left your compass at home. You can’t find a suitable tree trunk
to test the hypothesis that moss always grows on the north facing side. You’ve
got a standard watch (not digital) and the sun is shining. You’re safe. You’ll
be able to find your directions with a fair amount of precision by following
this very simple procedure. Orient yourself so that the hour hand of your watch
is pointed towards the sun. The midway point between the hour hand and the
12 o’clock position points south. It’s that simple. Flip yourself around so
that you are now facing north. Moving in a clockwise direction, in quarter
circle increments, remembering, that North never Eats Soggy Waffles. You have
now delineated the four cardinal points and can begin to get a bearing on your
situation. If you would want to use this same technique to find directions
during Daylight Savings Time, use the 1 p.m. position on your watch as the
second marker. The midpoint location between the hour hand, which is pointing
at the sun, and the 1 p.m. spot on your watch indicates south. If you’d like
to contribute an idea to StarWatch, e-mail the author at gabecker@itw.com or
mail to ASD Planetarium, Dieruff H.S., 815 N. Irving St., Allentown, PA 18103-1894.
Mrs. Terry Ehrenreich of Catasauqua suggested this topic. Happy New Year!
-