(meteorobs) NAMN Notes: November 2004

Mark Davis meteors at comcast.net
Mon Oct 18 18:01:26 EDT 2004 

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NAMN Notes:  November 2004
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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.  Leonids - the Aftermath...
2.  Alpha Monocerotids to Monitor...
3.  Taurids - Fireballs this Year?...
4.  Other Showers and Items of Interest...
5.  Winter Comets...
6.  Upcoming Meetings...
7.  For more info...


1.  Leonids - the Aftermath...

The Leonids (LEO) have graced our skies in large numbers the past handful of
years, and the nights of our meteor storms are over for now.  However - this
is a shower that warrants observation, as we may yet be treated to some
surprises!

According to the IMO, the International Meteor Organization, in their 2004
Meteor Shower Calendar:

"In theory, the ending of the strong to storm Leonid returns between
1998-2002 associated with particles accompanying the shower's parent comet,
55P/Tempel-Tuttle, which had returned to its perihelion in 1998, should mean
2004 will see a continuing decline in activity back towards its earlier ZHRs
of 10-15.  Certainly, no enhanced activity is predicted, although as meteor
enthusiasts know well, surprises can occur from even the best-known showers
on occasion!"

"Observers should be alert to covering whatever the shower produces, as
following the post-storm phases after this best-ever observed run of storm
returns is as vital to our understanding of the stream as seeing the storms
themselves."

The Leonids will reach a maximum on November 17th this year, at about 8h 25m
UT, according to the IMO.  For North American observers, this means about
3.25 a.m. EST.  They can be seen from about November 14th to 21st.  These
are fast meteors, at about 71 km per second.

ZHR rates are listed as 10-50+ meteors per hour.  What is ZHR?  It 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.  A map
showing the radiant can be found on the IMO website at
http://www.imo.net/calendar/cal04.html#Leonids.

So, what are the meteor researchers predicting this year, as far as unusual
activity goes?

Jeremie Vaubaillon and Francois Colas, in collaboration with Esko Lyytinen,
Markku Nissinen and David Asher, have posted some comments on the IMCCE
website, the Institut de Mecanique Celeste et de Calcul des Ephemerides, at
http://portail.imcce.fr/en/ephemerides/phenomenes/meteor/leonids

They do predict some interesting activity in 2004, as the Earth will pass
close to 2 streams of debris, shed by the parent comet in 1333 and in 1733:

The 1333 stream is predicted to give enhanced activity of about ZHR 10
meteors per hour, on November 19th at 6h 42m UT, ie. 1.42 a.m. EST for North
American observers.

The 1733 stream is predicted to give enhanced activity of about ZHR 65
meteors per hour, on November 19th at 21h 49m UT, ie. 4.49 p.m. EST for
North American observers.

Vaubaillon emphasizes in the conclusion:

"Again this year it is very important to observe, even if the level will not
be as high as in past years!  Remember that your results are useful for
us...  Please, send your observations to IMO."

The detailed paper published by this group in the IMO's publication WGN will
be released shortly - and can be accessed through the links at the IMCCE
website (go to 2004 forecastings, then scroll down to links):
http://portail.imcce.fr/en/ephemerides/phenomenes/meteor/leonids

To read the ongoing comments about predicted activity, we suggest you join
our MeteorObs discussion group!  Our online 'subscribe' form can be found at
http://www.meteorobs.org/subscribe.html.  You can use this simple form to
subscribe - or unsubscribe - at any time.  By signing on, you will be able
to read all the up to date discussions - and hear about the meteor
observations around the globe, as they are reported!

If you want to record data on these showers for the meteor researchers,
check out our 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.  For estimating the brightness of the meteors you see, we have a
handy set of 4 star charts (set printer to 'landscape mode') at
http://www.namnmeteors.org/charts.html.  If you have any questions, drop a
note to our NAMN Coordinator at meteors at comcast.net

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

NAMN, our North American Meteor Network, also forwards observations to
the IMO, the International Meteor Organization, so that your data can be
used internationally to learn more about the Leonid meteor shower.  Help us
to contribute - get out to observe this fascinating shower!


2.  Alpha Monocerotids to Monitor...

The alpha Monocerotids (AMO) peak on November 21st - and should be watched
carefully!  This shower is classed as 'variable' and has been known to have
outbursts.

The ZHR rate is usually around 5 meteors per hour, but the shower has had
rates as high as over 400 meteors per hour.  The maximum this year is at 8h
45m UT, which is 3.45 a.m. EST for North American observers.  The shower can
be observed from about November 15th to 25th.  These meteors are fast, with
a velocity of about 65 km per second.

At maximum on the 21st, the radiant will be at 117 degrees, ie. RA 7h 48m,
Dec +01.  A map showing the radiant can be found at
http://www.imo.net/calendar/cal04.html#alpha-Monocerotids


3.  Taurids - Fireballs this Year?...

The northern and southern Taurids are an interesting pair of meteor showers
in our November skies.  These meteors are part of the 'Taurid stream' which
has been associated with Comet Encke.

The southern Taurids (STA) reach a peak on November 5th, and can be seen
until about the 25th.  These are almost slow meteors, with a velocity of
about 27 km per second.  The northern Taurids (NTA) peak on November 12th,
and can also be seen until about the 25th.  These are similar in velocity to
the STA's, at about 29 km per second.  ZHR rates for both are about 5
meteors per hour at their peak, although rates away from the peak dates will
be lower.    For a map showing the movement of the radiants throughout the
month, check out http://www.imo.net/calendar/cal04.html#Taurids.  According
to the IMO:

"The activity of both streams produces an apparently plateau-like maximum
for about ten days in early November, and the showers have a reputation for
producing some excellently bright fireballs at times, although seemingly not
in every year.  David Asher has indicated that increased Taurid fireball
rates may result from a "swarm" of larger particles within the Taurid stream
complex...  The next potential October-November "swarm" return is not
predicted until 2005, but we cannot be sure how correct this is as yet... "


4.  Other Showers and Items of Interest...

The Orionids (ORI), although having reached a maximum on October 21st, can
be seen until about November 7th.  These are fast meteors, with a velocity
of about 66 km per second.  Around the time of maximum, ZHR rates were about
23 meteors per hour, but rates in November will be lower.  These meteors are
debris from Halley's Comet, which can be traced back to the year 240 B.C.
The appearance of the comet in the 1980's produced a tail of only about 15
degrees in length, and a maximum brightness of about 2.6, fainter than the
stars of the Big Dipper.  However, Halley's Comet has a wonderful history -
which is what makes the comet so special, and the meteors especially
rewarding to observe!  A map showing the radiant positions in November can
be found on the IMO website at
http://www.imo.net/calendar/cal04.html#Orionids

The chi Orionids (XOR) start to become active about November 26th, although
will not reach a maximum until December 1st.  These are almost slow meteors,
with a velocity of about 28 km per second.  ZHR rates at maximum will be
about 3 meteors per hour, with November rates less.  A map showing the
radiant can be found at http://www.imo.net/calendar/cal02.html#chi-Orionids.

The Phoenicids (PHO), although a more southerly shower, merit note.  They
peak on December 6th at 2h 35m UT (ie. 9.35 p.m. EST on December 5th), but
can be observed starting about November 28th.  They are quite slow, with a
velocity of about 22 km per second.  ZHR rates are variable - usually 3 or
fewer meteors per hour, but did reach about 100 meteors per hour back in
1956.  A map of the radiant can be found at:
http://www.imo.net/calendar/cal04.html#Phoenicids.

Lastly, the Monocerotids (MON) start to become active about November 27th,
although do not peak until December 8th, and telescopic results suggest
perhaps not until December 16th.  These are average velocity meteors, at
about 42 km per second.  ZHR rates are only about 3 meteors per hour at the
peak, and less in November.  The meteors are usually faint.  The radiant can
be seen at http://www.imo.net/calendar/cal04.html#Geminids

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

Planets at midmonth, and their magnitudes, for northern observers, are:
Venus      -4.0   in Virgo, in east in morning sky
Jupiter     -1.8   in Virgo, in east in morning sky
Mercury  -0.3   in Scorpius, low in southwest in evening sky
Saturn       0.1   in Gemini
Mars        1.7   in Virgo, in east in morning sky
For a map of your sky with all the visible planets marked, check out the
website of 'Heavens Above' at http://www.heavens-above.com

There are all kinds of great planetary configurations in our skies this
month!  Take a look while you are out meteor observing:

Thurs. Nov. 4 (just before peak of southern Taurids):
Venus 0.6 degrees north of Jupiter

Tues.  Nov. 9:
Jupiter 1.0 degree south of the moon
occultation visible from central and eastern Canada, the northeastern United
States, Greenland, and Iceland
(1st in a series of 11 occultations ending on Aug. 10, 2005)

Wed. Nov. 10:
Venus 0.2 degrees north of the moon
occultation visible from India, southeast Asia, Australia and New Zealand

Thurs. Nov. 11 (just before peak of northern Taurids):
Mars 0.5 degrees north of the moon,
occultation visible from eastern Africa, the Indian Ocean, Tasmania, and
most of New Zealand

Sun. Nov. 14:
Mercury 0.9 degrees north of the moon,
occultation visible from Antarctica!

This month, the phases of the moon are as follows:
Fri. Nov.  5     last quarter
Fri. Nov. 12    new moon
Fri. Nov. 19    first quarter
Fri. Nov. 26    full moon
For a great printout of moon phases for the month, check out
http://stardate.org/nightsky/moon

Lastly, if you want to get a really new perspective on what's up there in
our night sky, check out the 'Current Map of the Solar System', courtesy of
the Armagh Observatory, at http://szyzyg.arm.ac.uk/~spm/neo_map.html.


5.  Winter Comets...

We are used to hearing about meteor showers originating from various
comets - but we should be encouraged also to take a look at the comets that
are visible in our night skies!  For observers with backyard telescopes,
there are a number of opportunities to observe comets in November.

One of the brightest comets will be C/2004 Q2 Machholz, discovered by Don
Machholz of the southwestern United States on August 27th.  He found this
comet from the back deck of his home, using his 6 inch f/8 Criterion
Dynascope, with a 2 inch eyepiece yielding 30x and a field of view about 2
degrees.  This discovery brought his comet hunting time up to 7046 hours
since January 1, 1975, and 1457 hours since his previous comet find in 1994!

Following are some of the best websites for information on comets visible
this month:

Seiichi Yoshida's Weekly Information about Bright Comets:
http://www.aerith.net/comet/weekly/current.html

Summary of Bright Comet Visibility in Northern Hemisphere:
http://www.aerith.net/comet/future-n.html

Summary of Bright Comet Visibility in Southern Hemisphere:
http://www.aerith.net/comet/future-s.html

Greg Crinklaw's "Skyhound" - Comet Details and Printable Finder Charts:
http://www.skyhound.com/sh/skyhound.html

Coordinates for Observable Comets (Harvard site):
http://cfa-www.harvard.edu/cfa/ps/Ephemerides/Comets/index.html


6.  Upcoming Meetings...

September 15-18, 2005, Belgium...
The 2005 IMC, International Meteor Conference of the IMO, the International
Meteor Organization, will be held in Oostmalle, Belgium.  Oostmalle is about
70 km north of Brussels, and about 30 km northeast of Antwerp.  The
conference is being organized by Urania, the public observatory of Antwerp.
Accommodation will be at the Provinciaal Vormingscentrum Malle, with an
excursion to the city of Lier.  This is a great opportunity to meet and
chat with meteor observers from all around the globe - so mark it on your
calendar now, and plan to attend!  The participation fee is 120 EUR, and
includes all accommodation, all meals, and the conference registration.  For
information, check out the conference website at http://www.imo.net/imc2005.
For questions, contact Jan Verbert at imc2005 at imo.net

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
Metcalfe, Ontario, Canada
Writer, NAMN Notes

Lew Gramer, dedalus at alum.mit.edu
Medford, Massachusetts, 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

==============================================
Here's to 'Clear Skies' for November...

November 2004 NAMN Notes
written by Cathy Hall & edited by Mark Davis
==============================================

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