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(meteorobs) NAMN Notes: September 2002
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NAMN Notes: September 2002
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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. Alpha Aurigids... September's Main Shower...
2. Other Activity This Month...
3. August Fireballs...
4. Web People - Time to Update Before Leonids...
5. Upcoming Meetings...
6. For more info...
1. Alpha Aurigids... September's Main Shower...
After all the many showers to keep track of in August, September is a quiet
month in comparison. However, this is not necessarily a bad thing! With
the promise of a very active November with a Leonid storm coming up, meteor
observers can use some time between now and then to prepare and make plans
for that special event...
The alpha Aurigids (AUR) reach a maximum on the 1st, so the first weekend of
September is the prime observing time for this shower! The radiant will be
at 084 degrees, ie. RA 5h 36m, Dec +42, which is about 5 degrees to the left
of the star eta Auriga, a star with the rather cool name of Hoedus II.
These are fast meteors, with a velocity of about 66 km per second. They can
be seen only until about September 5th.
The alpha Aurigids are believed to be associated with Comet Kiess 1911 II.
This comet was discovered by C.C. Kiess of the Lick Observatory on a
photographic plate taken with the Crocker Photographic Telescope. It has an
elliptical orbit with a period of about 2500 years.
The Zenithal Hourly Rate (ZHR) at maximum will be about 10 meteors per
hour. This is the average number of meteors that an observer would expect
to see with the unaided eye, 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. According to the IMO, the International Meteor
Organization, in their 2002 Meteor Shower Calendar, the alpha Aurigids "peak
on September 1, 6h UT", so that would be the time to expect the highest
rates.
The activity level has been known to vary from year to year, and can
occasionally be 3 to 5 times higher. So - get out and take a look at this
shower, and let us hear about your observations!
2. Other Activity This Month...
September has little main shower activity besides the alpha Aurigids, if you
look at the 2002 IMO Meteor Shower Calendar at
http://www.imodot net/calendar/cal02.html.
The delta Aurigids (DAU) reach a maximum on September 8th, with a radiant at
060 degrees, ie. RA 4h 00m, Dec +47, which is about 3 degrees to the left of
the star delta Perseus. These are fast meteors, with a velocity of about 64
km per second. At maximum, ZHR rates will be about 6 meteors per hour. The
shower lasts until about October 10th, but with lesser rates.
The Piscids (SPI) last for the whole month of September, but reach a maximum
on September 20th. The radiant on that date will be at 005 degrees, ie. RA
0h 19.8m, Dec -01, which is about 15 degrees south of gamma Pegasus, the
bottom left star of the Great Square of Pegasus. These are slow meteors,
with a velocity of about 26 km per second. ZHR rates on the 20th will be
about 3 meteors per hour, and rates the rest of the month much less.
For information on minor showers visible in September - and there is always
minor activity - check out Gary Kronk's "Comets and Meteor Showers" website
at http://comets.amsmeteors.org.
One minor shower of note in September is the Aries-Triangulid activity
around September 12th, first detected by Gary Kronk of Illinois, George
Gliba of Maryland, and Kurt Sleeter of Illinois. Observers are encouraged
to watch for any possible activity this year. The radiant would be at
approximately RA 2h 00m, Dec +29, which is very near the star alpha
Triangulum. For more details, check out Kronk's website at
http://comets.amsmeteors.org/meteors/showers/aries_triangulids.html.
Another item of note is the daytime meteor shower called the Sextantids.
These are described in length on Kronk's site at:
http://comets.amsmeteors.org/meteors/showers/sextantids.html
This shower was discovered by A.A. Weiss in 1957 during radio studies in
South Australia. It is interesting that the International
Meteor Organization (IMO) comments on this shower this year in their
notes to visual observers:
"For daylight radio observers... there remain(s)... a tricky visual shower,
the Sextantids (maximum expected on September 27, 15h UT, but possibly
occurring a day earlier. In 1999 a strong return was detected at lambda
about 186 degrees, equivalent to 2002 September 29). The waning Moon
presents extra problems for visual observers hoping to catch some Sextantids
in late September, though the radiant rises less than an hour before dawn in
either hemisphere."
The average radiant position detected (by radio means) in 1961 was 151.7
degrees, ie. RA 10h 6.6m, Dec -0.1, which is very near the star alpha
Sextans, and about 12 degrees due south of the star Regulus in Leo.
Besides recognized main showers, and other minor showers, there is also
sporadic meteor activity in September. This sporadic activity is about 7
meteors per hour, visible to the unaided eye. This activity is comprised
partly of random meteors and partly of meteors that belong to long-ago, now
untraceable showers.
This month, the phases of the moon are as follows:
Sat. Sept. 7 - new moon
Fri. Sept. 13 - first quarter
Sat. Sept. 21 - full moon, the 'Harvest Moon'
Sun. Sept. 29 - last quarter
Planets this month are few in the evening sky. Venus sets very early, at
about magnitude -4.5. In the morning sky we have Saturn and Jupiter.
Saturn moves into Orion on September 1st, and gets quite high in the sky
this month at about magnitude 0. Jupiter is in Cancer, and by the end of
the month, will be about 20 degrees above the eastern horizon at the
beginning of morning twilight, at about magnitude -1.9.
For information on what to record when meteor observing, check out our NAMN
Observing Guide at http://www.namnmeteors.org/guide.html
For recording sheets for your meteors, go to
http://www.namnmeteors.org/reports.html
For some great star charts with standard stars marked, to use in
estimating the brightness of the meteors you see, go to
http://www.namnmeteors.org/charts.html
And - if you have any questions on observing, drop a note to our NAMN
Coordinator at meteors@comcastdot net.
3. August Fireballs...
A summary of August fireball reports submitted to NAMN is as follows, from
Kevin Kilkenny, our Coordinator, Fireballs and Meteorites:
Date Location Direction Mag. Fragmentation?
From-To
8/2 Midland, Ont. SE-S -10 yes
8/3 Effingham, Ill. E-W -3 no
8/9 Hayden Lake, ID N-W -8 no
8/11 Niagara Falls, Ont. N-NW -5 no
8/12 Fenton, MO N-NNW -6 yes
8/12 UK N-S -8 no
8/14 Las Vegas, NV S-N -5 yes
8/18 West Bend, WI SE-NE -11 yes
Anyone wishing to contribute to the international fireball database may do
so at:
http://www.namnmeteors.org/fireball/namnreport.html or at
http://www.namnmeteors.org/fireball/report.html for beginners or novices.
Questions on fireballs should be directed to Kevin Kilkenny at
Mail4Meteors@aol.com
4. Web People - Time to Update Before Leonids!...
This Canadian co-author has been doing some web cruising in preparation for
an upcoming article on the Leonid meteor shower in November... and finding
all kinds of deadbeat links out there in cyberspace! So... while your kids
are getting ready to go back to school this fall, here is some homework for
all of you as well!
If you have an astronomy webpage of any kind - your own personal page, or
for your group - go through it and check each and every cross-reference and
link. I have been finding all kinds of badly outdated links on pages.
These are not just in the "Links" sections of webpages, but throughout the
webpages themselves. I will be sending friendly emails to those I find in
hopes of getting them updated quickly.
With Leonids coming up in November - and web traffic due to exponentially
increase - broken links can mean problems for all observers trying to get
information on this big event. Please take this time now, in September, to
go through and make sure all the links and cross-references throughout
your website actually do work!
Some of the common addresses that have changed in the past couple years and
should be corrected on your websites include the following. I'm sure there
are many more links to correct, but these are just some of the ones I came
across on websites multiple times:
Dr. Peter Jenniskens' Leonid MAC site, correct address is now:
http://leonid.arc.nasadot gov
Sky and Telescope, correct address is now:
http://skyandtelescope.com
NAMN, North American Meteor Network, correct address is now:
http://www.namnmeteors.org
our NAMN Guide "Meteor Showers and their Observation",
correct address is now:
http://www.namnmeteors.org/guide.html
Gary Kronk's Comets and Meteor Showers, correct address is now:
http://comets.amsmeteors.org.
For those of you interested in doing a bit of advance reading on Leonids,
check out the following:
2002 Predictions by Robert McNaught and David Asher:
http://www.arm.acdot uk/leonid/encounters.html
2002 Predictions by Dr. Peter Jenniskens:
http://leonid.arc.nasadot gov/1998.html
(and yes, although it is labeled weird, this is the correct address!)
2002 Predictions by Esko Lyytinen, Markku Nissinen and Tom Van Flandern:
http://www.ursa.fi/ursa/jaostot/meteorit/leoeng02.html
More information on the Leonids will be coming up in the next issues of NAMN
Notes... and we hope that by then, all of your websites will be up to date
as well!
5. Upcoming Meetings...
September 3-6, Washington, DC, USA...
The Workshop on Scientific Requirements for Mitigation of Hazardous Comets
and Asteroids, sponsored by NASA, will be held in Washington, DC. The
workshop will review current knowledge of the physics and chemistry of the
interiors of small cometary nuclei and asteroids, and will work towards
several goals: determination of requirements for collision avoidance and
impact mitigation technologies, determination of mission models and
instrumentation needed, and construction of a roadmap for achieving the
knowledge on which to base future systems to deal with possible impacts.
A list of the confirmed invited speakers can be found at
http://www.noaodot edu/meetings/mitigation/invited.html. For information,
contact Nalin Samarasinha at nalin@noaodot edu and check out the conference
website at http://www.noaodot edu/meetings/mitigation.
September 26-29, 2002, Frombork, Poland...
IMC 2002, the International Meteor Conference, will be held in Frombork,
Poland. This is the annual conference of the International Meteor
Organization and welcomes all meteor observers, both amateur and
professional. For information, check out http://www.imodot net and
http://www.astrouwdot edu.pl/~olech/pkim/imc2002/imc.html. For specific
questions, contact Mariusz Wisniewski at pkim@astrouwdot edu.pl
For more information on upcoming astronomy meetings, see: "International
Astronomy Meetings List" http://cadcwww.hia.nrcdot ca/meetings
6. For more info...
NAMN email: namn@atmob.org
NAMN website: http://www.namnmeteors.org
Mark Davis, meteors@comcastdot net
Goose Creek, South Carolina, USA
Coordinator, North American Meteor Network
Cathy Hall, chall@cyberusdot ca
Metcalfe, Ontario, Canada
Co-author, NAMN Notes
Lew Gramer, dedalus@alum.mitdot edu
Medford, Massachusetts, USA
Coordinator, Public Outreach
Owner/Moderator, 'MeteorObs'
Kevin Kilkenny, Mail4Meteors@aol.com
Staten Island, New York, USA
Coordinator, Fireballs and Meteorites
Back issues of NAMN Notes can be found on-line 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 or to find out information on our
weekly chat sessions:
Contact Lew Gramer at: dedalus@alum.mitdot edu
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Here's to 'Clear Skies' for September...
September 2002 NAMN Notes co-written
by Mark Davis and Cathy Hall
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