TOTAL LUNAR ECLIPSE, 27-28 SEPTEMBER 2015
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John Pazmino
NYSkies Astronomy Inc
www.nyskies.org
nyskies#nyskies.org
2015 September 12
Introduction
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On the evening of September 27th into owl hours of September 28,
2015, a total eclipse of the Moon takes place over New York City and
vicinity. It is in fact witnessed over just about all of the Western
Hemisphere, allowing you to view it from a wide variety of other
locations, such as a vacation house or holiday travel.
This eclipse falls on Sukkoth, a major Hebrew holiday. Some
cultures may have special rituals or observances for this eclipse.
Facts and concepts
----------------
A lunar eclipse is the passing of the full Moon into the shadow of
Earth. The Moon is darkened, while in the shadow. A dim reddish glow
may be seen from seepage of sunlight onto the Moon from the atmosphere
around Earth.
The Earth's shadow consists of an inner dark core, the umbra, and
a thin weaker outer zone, the paenumbra. You'll se the paenumbra only
near the start and end of partial phase. It shows as a brownish stain
on the edge /of the Moon where the umbra enters or leaves.
Eclipses of the Moon occur frequently but are sometimes missed
because of cloudy weather or timezone displacement. A lunar eclipse is
visible from the whole night side of the Earth.
A detailed treatment of eclipses, lunar and solar, is in a
separate article 'Eclipse facts and concepts' at
www.nyskies.org/articles/pazmino/ecl-fact.htm.
It collects boiler-plate and permanent material which other wise must
be repeated over and over again for each eclipse.
Preparation
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There is NO danger of harm to eyesight in a lunar eclipse. You are
looking at, at worse, the normal full Moon until it is covered -- and
greatly dimmed -- by the Earth's shadow. No other preparation is
needed except to dress adequately for weather. The eclipse can be
appreciated by bare eye and binoculars. A regular telescope is not
necessary, altho if one is to hand, do examine the eclipse with it.
The viewing location ideally should have an open sky from east
thru south to lessen the need to skip around close obstructions. An
open sky shows more of the stars when the Moon is fully immersed in
the umbra.
Timetable of activity
-------------------
The timetable here gives the activity during the night of
September 27-28. All hours are Eastern Daylight Savings Time. The
column 'alt-az' gives the height and bearing of the Moon, like for
navigation or surveying, in degrees.
The hours in this table may differ a minute or two from other
sources due to your offset from the Eastern timezone meridian and the
methods used for the calculations.
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TOTAL LUNAR ECLIPSE, 2015 SEPTEMBER 27-28 IN NEW YORK
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EDST | event | alt-az | remarks
------+----------------+--------+--------
18:36 | Moon rises | 00 089 | selenehelion
18:45 | sUn sets | 01 091 | end of daylight
19:12 | civil twilight | 05 095 | end of daytime work
19:43 | naut twilight | 11 100 | start of full night in NYC
20:47 | first shde | 21 111 | paenumbra shade on Moon
21:07 | 1st contact | 26 115 | partial phase begins
22:11 | 2nd contact | 36 128 | total phase begins
22:47 | mid eclipse | 42 137 | Moon deepest in umbra
23:23 | 3rd contact | 46 149 | total phase ends
00:00 | midnight | 49 161 | Sep 27 -> Sep 28
00:27 | 4th contact | 50 171 | partial phase ends
00:47 | lst shade | 51 178 | paenumbra shade on Moon
00:52 | Moon transit | 51 180 | Moon highest in south
05:49 | naut twilight | 14 260 | end of full night in NYC
06:21 | civil twilight | 07 185 | strt of daytime work
06:48 | Sun rises | 04 270 | start of dayligh
07:16 | Moon sets | 00 274 | selenehelion
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Viewing the eclipse
-----------------
You may watch the eclipse from any handy site, so long as the sky
is open over you and the Moon is in sight. If you plan to watch from a
location beyond your management, do obtain permission to enter into it
for the eclipse. Many public lands close at night and occupants found
within them without proper permission in hand may be shooed off.
The long duration of a lunar eclipse allows for social groups,
like a garden party. The slow progress permits breaks to socialize,
fill up on eats and drink, listen to music. You will want to catch the
'contact's, when the shadow touches the Moon tangently.
At sunset and again at sunrise you may see the nearly full Moon
at the opposite side of the sky. This apparition, a selenehelion,
occurs a few times each year. Usually the full Moon is not seen with
the Sun together, The one leaves the sky first, then the other comes
into view.
Public viewings
-------------
It is not necessay to view from a specific location but a public
eclipse session will typicly have astronomers to explain the eclipse
and give an introductory presentation about it. The session usually
sets up telescopes for close-up views of the eclipse. You may bring
your own binoculars and the charts from this article.
Ask at local nature or environmental centers, nature or science
museum, observatory or planetarium, college astronomy or physics
departments for public viewing of the eclipse. They may have other
astronomy programs of interest for you after the eclipse.
If the session is in an open field, bring a sweater or jacket for
possible chilly wind. A folding stool is handy if there are no seats
or benches at the site.
New York's sky
--------------
The eclipse occurs a few days after the autumn equinox when the
Moon sits in the 4th degree of sIgn Aries. The Moon movES northward
thru the shadow, yet the eclipse is at the lunar descending node. The
motion is confusing because at this point in the zodiac the ecliptic
is crosses the autumn equinox on a path from south to north at an
angle of 23-1/2 degree. This is a bit MORE than the slope of the
Moon's path, which actually crosses the eclipse from north to south.
The sky is filled with the stars of mid autumn as seen in
nightfall hours. Above the Moon is the Square of Pegasus, an anchor or
point group for many other autumn stars. In the high north, thru mid
east, thru mid southeast are the constellations of the Andromeda
legend, the only coordinated placement of constellations in the
heavens related to a single story. They are Cepheus, Cassiopeia,
Andromeda herself, Perseus, and Cetus. Pegasus is also in this
Andromeda story.
The region from low southwest thru the Moon, to the southwest
horizon is the 'Ocean' or 'Sea' where many constellations have an
aquatic character. From low in southwest thru the Moon are the watery
zodiac constellations of Capricornus, Aquarius, Pisces.
Anpve Capricornus is Delphinus. Below the Moon in low south is
Piscis Austrinus and Grus.. From the Moon to the southeast horizon are
Cetus and Eridanus.
In the eastern half of the sky are the stars of winter: Taurus,
Orion, Auriga,, Gemini. The western half is occupied by the last stars
of summer around the Summer Triangle, Hercules, and Ophiuchus,
Planets Uranus and Neptune are in high south, but they can wait
until the Moon moves on, out of the night sky, in a couple weeks.
Photography
---------
Ty taking pictures of the eclipse. The camera must be held still,
propped on a solid support like a table, window sill, parapet. Be
sure it is aiming at the Moon by checking the scene in the viewing
screen.
Engage the delayed-shutter.
For a wide-angle scene with stars around the Moon set the exposure
to several seconds. For a zoom view of the Moon itself, let the camera
find the exposure in 'auto' mode,
Then set the camera on its support and start the exposure. Leave
it alone until the shutter closes,
Most camera models -- but not all -- will relapse to focus to
'infinity' if there is no target for the auto-focus to lock on. It
will NOT lock on the Moon. You may have to manually set the focus to
infinity.
The wide-angle image may seem empty when inspected on the camera's
screen or even on the computer. Zoom in on the Moon and scroll around
it. You should see the stars as tiny points here and there. Try to
match them with the sky chart.
Tetrad
----
This eclipse is the last of a set of four, a tetrad, that included
total lunar eclipses in April 2014, October 2014, April 2015, and now
September 2015. Tetrads are very unevenly spaced over the decades. The
last was in 2003-2004 and the next is in 2032-2033. In between there
are single and pairs of lunar eclipses.
We are heavenly blessed with tetrads for in the 20th century there
were five and in the 21st we enjoy eight of them. On the other hand
there were NO TETRADS AT ALL in all of the 17th, 18th, and 19th
centuries.
After this eclipse the next one for the City, while not part of a
tetrad, is on 20-21 January 2019, also in evening thru owl hours.
The 2014-2015 tetrad is specially interesting because all four
eclipses occur on important Hebrew holidays. These eclipses for this
reason are sometimes called 'Blood Moons' with warnings of doom and
disaster. The April 2014 and April 2015 are on Passover; the October
2014 and September 2015 are on Sukkoth.