(meteorobs) NAMN Notes: December 2006

Mon Dec 11 21:00:27 EST 2006

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NAMN Notes:  December 2006
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Introduction:
NAMN Notes is a monthly newsletter produced by the North American Meteor
Network and is available both via email and on the NAMN website at:
http://www.namnmeteors.org

Contents:

1.  NAMN Notes, 100th Issue...
2.  Geminids, The Jewel of the Meteor Year...
3.  Ursids, Our Christmas Shower...
4.  Other December Meteor Activity...
5.  Other Meteor Observing Methods...
6.  Upcoming Meetings...
7.  For more info...

1.  NAMN Notes, 100th Issue...

It is hard to believe that this is the 100th issue of NAMN Notes...

NAMN Notes' first official issue was September 1998.  Our newsletter is one
of the voices of the North American Meteor Network - but not the only one.
And although we started out as a North American voice, our audience is now
worldwide.

NAMN Coordinator Mark Davis 'holds down the fort' in Charleston, South
Carolina.  Mark spends many hours archiving meteor reports from around the
globe, forwarding data on to the International Meteor Organization (IMO),
answering queries, maintaining our website, and also maintaining
correspondence with those meteor observers not on the net.

Lew Gramer resides in southern Florida.  Lew handles outreach activities,
gives talks on meteors on behalf of NAMN, and handles our computer issues.
He also maintains the MeteorObs list service and archive that are used by
amateur and professional meteor observers around the globe.

Kevin Kilkenny, in New York City, handles the hundreds of fireball reports
that we receive over the course of the year and answers all our meteorite
questions.

Another valuable NAMN member who keeps a low profile, but deserves many
thanks, is Wayne Hally, in the wilds of New Jersey.  Our 'Meteor Wayne'
provides training for observers, gives many talks on meteors and NAMN
throughout the year, and is always there to help us out.

Your NAMN writer, Cathy Hall, is bundled up in her parka in the 'Great
White North' of Ottawa, Canada.  She tries to help spread the word about
meteor activity and NAMN to as many people as possible.

There are many other people out there who help us out at NAMN.  We want to
thank Brewster LaMacchia in particular - a behind-the-scenes computer guru
who helps keep the communication lines open for our meteor community.
Internet communication has brought us all together - and it is communication
and cooperation that will keep us together.

We'd like to wish you all a simple, quiet holiday season - with lots of
starry nights, lots of time for quiet reflection away from the noise and
chaos of the modern world - and lots of quiet meteors floating across your
skies...

Merry Christmas, Happy New Year - and Clear Skies to all!

2.  Geminids, The Jewel of the Meteor Year...

The Geminids (GEM) are the highlight of the meteor year for many observers.
The winter nights are long, and the meteors are impressive.

This year, the Geminids reach a peak on December 14th, at about 10h 45m UT,
Universal Time, according to the International Meteor Organization.
Converting UT, the time at Greenwich, England, to EST for observers in
eastern North America, we get a peak of 5.45 a.m. on Thursday the 14th.  The
shower runs from about December 7th to the 17th.

At the peak, the ZHR rates are expected to be about 120 meteors per hour.
ZHR stands for Zenithal Hourly Rate, and is the average number of meteors
that an observer would expect to see in an hour, if they are out under a
dark country sky, and if the radiant, the area in the sky where the meteors
seem to come from, is directly overhead at the zenith.

A map showing the radiant of the Geminid shower can be found on the IMO
website at http://www.imo.net/calendar/2006/fall

The parent body of the Geminid meteors is the asteroid 3200 Phaethon.  This
was announced by the International Astronomical Union (IAU) in 1983, and was
the first time that an asteroid, as opposed to a comet, had been linked to a
meteor shower.  Some researchers say that Phaethon is the largest remnant of
the parent of the Geminid stream, and that it is still unclear as to what
the true parent is.  The IMO states that "the first indications of the
Geminid meteor shower were published by the early Belgian meteor researcher
Quetelet (1841, 1861), who mentioned high meteor activity on 1830 December
12-13 at Heiligenstadt (Germany), from where 40 fireballs were reported."

These are average velocity meteors at about 35 km per second.  As many of
the meteors can be bright, this is a very rewarding meteor shower for both
beginners and seasoned observers alike.

The IMO comments on Geminid activity, and also encourages telescopic
observations for experienced observers:

"One of the finest annual showers presently observable...this is a
splendid stream of often bright, medium-speed meteors, a rewarding sight for
all watchers...Some mass-sorting within the stream means the fainter
telescopic meteors should be most abundant almost...one day... ahead of the
visual maximum, with telescopic results indicating these meteors radiate
from an elongated region, perhaps with three sub-centres."

All observations are encouraged - not only on the peak, but on the other
nights from the 7th to the 17th as well depending on what nights you happen
to get clear skies.  This shower has shown some slight signs of variability
in rates and timing, and observations on all nights are very scientifically
useful.  Even beginning observers should note that the Geminids are very
plentiful not just on the peak, but for several nights around the peak as
well.

If you want to record visual data for the meteor researchers,
check out the NAMN Observing Guide for information on what to record.  Our
Guide can be found at http://www.namnmeteors.org/guide.html.  We record such
info as the time a meteor occurred, its magnitude (brightness), the shower
it belongs to, its speed, and other comments such as train left behind, or
color.  General information to record includes such things as how dark your
perceived sky is (limiting magnitude), and comments on weather and cloud
cover.  If you have any questions, drop a note to the NAMN Coordinator at
meteors at comcast.net

For visual observers, NAMN has a set of 4 star charts to help you judge the
brightness (magnitude) of the meteors you see.  They are also a great tool
for new observers to help you learn your constellations better.  The charts
can be printed off from http://www.namnmeteors.org/charts.html.  Set your
printer to landscape mode.

Forms to record your observations can be found at
http://www.namnmeteors.org/namn_form.html and
http://www.namnmeteors.org/appendixC.html

Get out for the Geminids - they are considered by many observers to be the
best meteor shower of the year!

3.  Ursids, Our Christmas Shower...

The Ursids (URS) are regarded by many of us to be our Christmas shower as
the peak is very close to the holiday season.  This year, the meteors reach
a maximum on December 22nd, at about 19h UT, Universal Time.  For observers
in eastern North America, this means about 2 p.m. EST.

These are average velocity meteors, at about 33 km per second and tend to
be faint.  They can be seen from about December 17th to 26th.

ZHR rates are good - about 10 meteors per hour at the peak.  There have
also been several outbursts in the past 60 years - in 1945 and 1986 - and
some years with lesser but enhanced rates - 1988, 1994 and 2000.  As listed
on Gary Kronk's 'Comets and Meteor Showers' website at
http://comets.amsmeteors.org, the ZHR rate in 1945 was 108 (from
observations in Czechoslovakia) and in 1986 reached 122 meteors per hour
(from observations in Norway).

The Ursids have an association with Comet Mechain, now called Comet Tuttle.
Pierre Mechain of France discovered the comet on January 9, 1790, but there
were not enough observations of it to discover its periodic nature.  It was
recovered on January 5, 1858 by Horace Tuttle of Massachusetts and given
his name instead.

The radiant of the Ursids at their peak is at 217 degrees, ie. RA 14h 28.2m,
Dec +76, which is just above the pointer stars of Ursa Minor, the Little
Dipper.  For a map showing the radiant, check out the IMO website at
http://www.imo.net/calendar/2006/fall

The Ursids are really in need of more observations due to their proximity
to the holiday season.  Will there be an outburst this year?  Treat yourself
to some holiday cheer - Ursids under new moon skies!

4.  Other December Meteor Activity...

December has a lot of meteor activity for those observers willing to brave
the cooler nights - and those nights can hold some surprises.

The chi Orionids (XOR) peak on December 2nd, but the full activity lasts
from November 26th through to December 15th.  These are almost slow meteors,
with a velocity of about 28 km per second.  ZHR rates at the peak will be
about 3 meteors per hour - but observers can be rewarded with occasional
fireballs.  According to the IMO, this is "a weak visual stream, but one
moderately active telescopically."  A map of the radiant can be found at
http://www.imo.net/calendar/2002

The December Phoenicids (PHO) peak on December 6th at about 15h UT, which
means 10 a.m. EST for observers in eastern North America.  They last from
November 28th through to December 9th.  This is a southern shower with a
radiant at -53 degrees, but is included for those in southern latitudes.
These are very slow meteors at about 18 km per second, so will be quite
distinctive.  The ZHR rate is listed as variable, which means observers
should always monitor the shower for unexpected activity.  The rate is
usually about 3 meteors per hour or less.  However back in 1956, rates did
reach about 100 meteors per hour at the peak.  A map of the radiant can be
found at http://www.imo.net/calendar/2004/fall

The Puppid-Velids (PUP) are a southern shower lasting from about December
1st to 15th, with a maximum about December 7th.  These are average velocity
meteors at about 40 km per second.  ZHR rates are about 10 meteors per hour
at maximum.  This is a poorly studied shower, with up to 10 substreams.
Observations are strongly encouraged so the meteor researchers can use the
data to learn more about this shower.  Plotting is encouraged.  Most of the
meteors are faint - but occasional fireballs have been reported.  The
radiant at maximum is at 123 degrees, ie. RA 08h 12m, Dec -45, which is
about 17 degrees down to the left of the star eta Canis Major.  A map of the
radiant can be found at http://www.imo.net/calendar/2007

The Monocerotids (MON) peak on December 9th and last from about November
27th until December 17th.  These are average velocity meteors at about 42
km per second, and are usually faint.  Both visual and telescopic
observations are encouraged over the whole activity period.  A map of the
radiant can be found at http://www.imo.net/calendar/2006/fall.  ZHR rates at
the peak are expected to be only about 3 meteors per hour - but this meteor
shower has a very interesting history.  The Monocerotids could be the source
of many of the spectacular fireballs of the eleventh century.  Many of these
were documented in the writings of Ma Touan-lin, a historian of the
pre-Mongolian era, who collected observations of over 1,500 fireballs going
back over 24 centuries.

The sigma Hydrids (HYD) reach a maximum on December 12th and can be
observed from about December 3rd to 15th.  These are fast meteors at about
58 km per second.  They are usually faint.  ZHR rates at the peak are
about 2 meteors per hour.  A map showing the radiant can be found at
http://www.imo.net/calendar/2004/fall.

Lastly, the Coma Berenicids (COM) peak on December 20th, and can
be observed from about December 12th through until January 23rd.  These are
fast meteors at about 65 km per second.  ZHR rates will be about 5 meteors
per hour at the peak.  A map of the radiant can be found at
http://www.imo.net/calendar/2006/fall.  The IMO comments that "this shower
is almost unobservable from the southern hemisphere, so northern watchers
must brave the winter cold to improve our knowledge of it.  The radiant is
at a useful elevation from local midnight onwards, and with a peak exactly
at new Moon, conditions are perfect."

For other December minor showers not on the International Meteor
Organization's 'Working List of Visual Meteor Showers', and for a wealth of
historical information on all showers, check out Gary Kronk's 'Comets and
Meteor Showers' website at http://comets.amsmeteors.org

Besides December's main activity and other minor showers, there is also
sporadic meteor activity.  This sporadic meteor activity is about 7 meteors
per hour, visible to the unaided eye.  Some of these are random, and some
belong to old untraceable meteor showers.

For those of you interested in plotting your meteors (recommended for
serious observations), special IMO plotting maps can be ordered through
Robert Lunsford of the International Meteor Organization.  For details,
contact him directly at lunro.imo.usa at cox.net

Planets at midmonth, and their magnitudes, for northern observers, are:

Venus    -3.8   very low in the southwest in evening twilight
Jupiter  -1.7   in Virgo, very low in the southeast in morning twilight
Mercury  -0.6   very low in the east-southeast in morning twilight
Saturn    0.4   in Leo
Mars      1.5   very low in east-southeast in morning twilight

Note that on December 10th the planets Mercury, Mars and Jupiter will all
be extremely close together in the sky, all within about 1 degree of each
other!  This is the closest grouping of 3 planets visible to the unaided eye
during the period 1980 through to the year 2050.  Also on December 10th, the
planet Saturn will be visible about 1.2 degrees south of the moon, with an
occultation visible from Norway, the British Isles, and most of Greenland.

On December 25th, the planet Uranus will be visible about 0.08 degrees south
of the moon, with an occultation visible from west and northwest South
America, the tip of northeast Africa, and Portugal.

The phases of the moon for December are as follows:
Tues. Dec.  5   full moon
Tues. Dec. 12   last quarter
Wed.  Dec. 20   new moon
Wed.  Dec. 27   first quarter
A wonderful monthly moon calendar can be printed off from
http://stardate.org/nightsky/moon.  For the NASA kids' calendar for the
month, go to http://spaceplace.nasa.gov/en/kids/calendar.shtml

One of the simplest sky charts can be found on the website 'Heavens Above',
at http://www.heavens-above.com.  Ignore the 'Register' bit.  Just 'Select'
your country, then your city, and then scroll down the page to 'Whole Sky
Chart'.  Type in what day you want, and pick a time of night.  Pick black on
white, as it's easier to read.  The maps show the constellations and the
positions of all the visible planets.

5.  Other Meteor Observing Methods...

Most of our comments on meteor showers involve visual observations, but
there are many different ways to observe meteors - and to gather useful
scientific information to help out the meteor researchers.

Information on various observing methods can be found at some of the
following links:

Telescopic:
http://www.imo.net/tele
http://www.imo.net/tele/equipment
http://www.imo.net/tele/observation
http://www.imo.net/tele/science

Photographic:
http://www.imo.net/photo

Video:
http://www.imo.net/video
http://www.molau.de/english.html

Radio:
http://www.imo.net/radio
http://www.imo.net/radio/practical/setups
http://www.imo.net/radio/practical/transmitters
http://www.imo.net/radio/practical/antenna

Interest in all of these alternative meteor observing methods keeps growing.

NAMN recently received an update from one of the enthusiastic FM radio
meteor observers, Matthew Fox of Kansas City.  Read about his projects at
http://phoxcite.com/phpBB2/viewtopic.php?t=90.  He has also developed
several tools for locating suitable radio transmitters, and he discusses
these on his site.  His inspiration?  An FM radio meteor project by Marianne
Gualtieri of New Jersey, details of her science project at
http://members.bellatlantic.net/~vze2n9fe/meteor/meteor.htm

There are many websites out there with inspiring stories for all of us.
Check out one of this writer's favorites for browsing:  'Personal Pages of
Astronomers' at http://www.richardbell.net/personal.html.  Some of our
meteor and comet community have their links on this list... if your personal
webpage is not listed, why not contact them and have it included.  Let's try
to spread the word about meteor observing as much as we can!

6.  Upcoming Meetings...

For information on upcoming astronomy meetings, see: 'International
Astronomy Meetings List' at http://cadcwww.hia.nrc.ca/meetings

7.  For more info...

NAMN email: namn at namnmeteors.org
NAMN website: http://www.namnmeteors.org

Mark Davis, meteors at comcast.net
Goose Creek, South Carolina, USA
Coordinator, North American Meteor Network

Cathy Hall, chall at cyberus.ca
Ottawa, Ontario, Canada
Writer, NAMN Notes

Lew Gramer, dedalus at alum.mit.edu
Homestead, Florida, USA
Coordinator, Public Outreach
Owner/Moderator, 'MeteorObs'

Kevin Kilkenny, namnfireball at earthlink.net
Staten Island, New York, USA
Coordinator, Fireballs and Meteorites

Back issues of NAMN Notes can be found online at the NAMN website and in
the MeteorObs archives at:
http://www.meteorobs.org by selecting 'Browse Archive by Month'

To subscribe to the meteor email list:
Contact Lew Gramer at: dedalus at alum.mit.edu

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Here's to 'Clear Skies' for December
... and a 'Merry Christmas' to all

December 2006 NAMN Notes
... from Davis and Hall :)
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