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(meteorobs) NAMN Notes: October 2000
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NAMN Notes: October 2000
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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://web.infoavedot net/~meteorobs
Contents:
1. Orionids - Debris from Comet Halley...
2. Draconids and Other October Showers...
3. Help a Kid to Learn about Meteors...
4. Upcoming Meetings...
5. For more info...
1. Orionids - Debris from Comet Halley...
The major meteor shower this month is the Orionids (ORI), which reach a
maximum on October 21st. The meteors that we will see from this shower
originates as debris shed from Comet Halley - but on one of its previous
passes by us many years ago. Observers in the future will get to observe
meteors from the particles shed by Halley just over a decade ago.
The area in the sky where these Orionid meteors will 'radiate' from is
located at 095 degrees, ie. RA 6h 19.8m, Dec +16, which is located by
following a line from the right star of the belt of Orion up through
Betelgeuse, the left shoulder star, and continuing on for about the same
distance. If it was any further, it would be in the left foot area of
Gemini.
Orionids are fast meteors, with a velocity of about 66 km/sec. The ZHR,
Zenithal Hourly Rate, is about 20 meteors per hour, visible with the unaided
eye if you are out in a dark country sky and if the radiant is directly
overhead. Orionids can be seen from about October 2nd on through until
November 7th, although the rates further from the maximum will be much less.
Many of the meteors will have trains left after their passage.
According to the IMO, the International Meteor Organization, the high rates
around maximum last for several days with several peaks of enhanced
activity. So, even if the best night is clouded out at your location, it is
still very useful to observe on the nights before and after October 21st.
The best time to observe on any given night will be after midnight once the
radiant has risen to a good height above your local horizon.
Observations of this 'well-known' meteor shower are always appreciated - as
there are still many things to be learned from the results. It is only
through continued observation that we can discover more detail about the
physical structure of the actual stream of the Orionid meteoroid particles
in space. Visual observations from around the globe give the professionals
the data they need to determine this!
2. Draconids and Other October Showers...
The Draconids - often called the Giacobinids (GIA) after their parent
comet - reach a maximum on October 8th, but can be seen from about October
6th to 10th. This is excellent timing for Canadian observers, due to the
long Thanksgiving weekend! The radiant at maximum will be at 262 degrees,
ie. RA 17h 28.2m, Dec +54, which is about 2 degrees north of the star beta
Draconis, called Restaban, on the shortest side of the head of Draco. These
are slow meteors, at about 20 km/sec, so will be very distinctive - and much
easier to catch on photographs!
The strength of the Draconid meteor shower has varied considerably over the
years, reaching 'storm' level in 1933 and 1946 when thousands were seen
and the sky looked like it was really falling! In Belgium in 1933,
observers counted about 78 meteors per minute. Because of its variable
nature - get out to observe this shower. Although chances of seeing any
activity from this shower in a given year are minimal, one of these years
you could be pleasantly surprised! Monitoring of this shower in both quiet
years and years of higher activity is very important to study this debris
from Comet Giacobini-Zinner. All results - negative or positive - are
useful.
There are other showers to watch for in October as well. The delta Aurigids
(DAU), although having reached a maximum in September with a ZHR rate of
about 6 meteors per hour, can be seen in low numbers until about October
10th. They are fast, with a velocity of about 64 km/sec. On October 10th,
the radiant will be at 095 degrees, ie. RA 6h 19.8m, Dec +49, which is very
near the star psi Auriga. There is a questionable link between these
meteors and Comet Bradfield C/1972 E1.
The epsilon Geminids (EGE) reach a maximum on October 18th, with a radiant
at 102 degrees, ie. RA 6h 48m, Dec +27, which is about 3 degrees up to the
left of the star epsilon Gemini, the star Mebsuta. Rates are low, with a
ZHR rate of about 2 meteors per hour. These meteors are very fast, at about
70 km/sec. They can be seen from about October 14th to the 27th. The
parent body for these meteors is theorized to be either Comet Ikeya or Comet
Nishikawa-Takamizawa-Tago.
Lastly, northern Taurids (NTA) and southern Taurids (STA) start to become
active in October although neither reaches a maximum until early November.
They can be seen all month. Both have fairly slow meteors, with northern
Taurids being about 29 km/sec and southern Taurids about 27 km/sec. ZHR
rates will reach about 5 meteors per hour for each in November, but October
rates will be much lower. The Taurid meteor stream has a possible
association with a group of objects, including Comet Encke.
On October 10th, Draconid weekend, radiant coordinates for NTA will be 029
degrees, ie. RA 1h 55.8m, Dec +14, and for STA will be 031 degrees, ie. RA
2h 4.2m, Dec +8. On October 20th, closer to Orionid time, radiant
coordinates for NTA will be 038 degrees, ie. RA 2h 31.8m, Dec +17, and for
STA will be 039 degrees, ie. RA 2h 36m, Dec +11. As both radiants are close
together, take a look at your star maps to tell them apart!
Basic star charts for you to use can be found at
http://web.infoavedot net/~meteorobs/charts.html
For October, phases of the moon are as follows:
Thurs. Oct. 5 - first quarter
Fri. Oct. 13 - full moon, the 'Hunters' Moon'
Fri. Oct. 20 - last quarter
Fri. Oct. 27 - new moon
Jupiter and Saturn, both in Taurus, are visible most of the night. Jupiter
is at magnitude -2.7 for most of the month, and Saturn at -0.1 for most of
the month. Jupiter is especially helpful for judging brighter meteors by.
Mars rises very low in the morning twilight at about magnitude 1.8. Venus
is in the evening twilight at about magnitude -4.0 but sets about 2 hours
after the sun.
If you are new to meteor observing, check out our NAMN Observing Guide at
http://web.infoavedot net/~meteorobs/guide.html
For more advanced information, explore the website of the IMO, the
International Meteor Organization, at www.imodot net.
3. Help a Kid to Learn about Meteors...
October - for some of us - brings Halloween, fall leaves, and preparation
for winter. This is also a good time of year to extend a hand, or offer
some of your time to encourage new people to get involved in astronomy and
meteor observing. We have many observers around the globe - but we should
always try to encourage new observers, to expand our observer base - for
now, and in the years to come.
There are many ways to 'reach out' this time of year. Kids are now back in
school and for many North American schools, astronomy has been added to the
curriculum. Teachers are always appreciative of amateur astronomers
offering to give talks or presentations to the kids. Consider offering your
time for an hour to give a talk - about astronomy perhaps in general, and
then about meteors in particular. Take in some things for the kids to look
at - such as posters or meteorites, if you have any - and give them
something in return to take home, such as a star map for each child and a
list of the main meteor showers!
The American Meteor Society has appointed a special 'Outreach Coordinator'
this past year, to help spread the word about meteor observing. One of his
prime interests is to help out at the educational level. If you are
interested in more information, or a list of resources - or if you are
interested in helping out - contact Lew Gramer, the AMS Outreach
Coordinator, at dedalus@latrade.com
Halloween itself offers a unique opportunity to offer some astronomy to the
masses. In North America, many observers have started going outside on
Halloween with a telescope, to offer the kids a look through a scope besides
the requisite treats. Although not directly meteor-related, it gives the
neighbourhood kids somebody to ask questions of - and you can tell them that
you don't need a telescope to see meteors and satellites! Check out the
times for satellite passes over your house at http://www.heavens-above.com
Another venue related to this, is sidewalk astronomy. One of the most
active groups in Canada, the Ottawa Valley Astronomy and Observers Group,
has been doing impromptu telescope sessions in shopping mall parking lots.
Not only do they show people the moon and some of the brighter sky objects -
but they hand out brochures on the North American Meteor Network! Check out
their website at http://members.homedot net/observers-group/
The basic idea in reaching out to new people is that you will get more
response - if you go to where the people are! Using public places - like
schools, or front lawns on Halloween, or shopping mall parking lots - will
help get the word out to kids about astronomy, and meteors, and light
pollution for that matter - far better than just waiting for them to find
us!
Clear skies - and Happy Halloween!
4. Upcoming Meetings...
September 20-23, 2001 - Slovenia:
IMC 2001, the annual convention of the International Meteor
Organization, will be held in Slovenia, and the IMO encourages all meteor
observers to start planning ahead now to attend! This is a worldwide
meeting for us - the observers - not just for professional astronomers!
Where is Slovenia? It is on the Adriatic Sea, just south of Austria. For
North Americans not familiar with the geography, the nearest well-known city
is the port of Venice, in northern Italy. If you read the AAA Europe
TravelBook, it mentions that this area actually used to be under Venetian
rule, from 1279 until 1797. Many of the towns and castles were built
between the 10th and 13th centuries. Slovenia was originally colonized by
the Romans, and along with a colourful historical past, also has many
geographical items of interest - including one of the largest underground
cavern systems in the world.
For North American meteor observers, Slovenia seems like a long distance
away. However, it makes a wonderful place for you - and your family - to
visit on your 2001 European holiday! While the wife and kids are taking in
the sights, you can be attending the IMC and meeting meteor friends from
around the globe...
The conference location is a mountain resort in the Julian Alps, northwest
of Ljubljana. For more information, stay tuned to the IMO website at
www.imodot net
Start planning now for "2001 - A Slovenian Odyssey"!
5. For more info...
Contact:
Mark Davis, MeteorObs@charlestondot net
Goose Creek, South Carolina, USA
Coordinator, North American Meteor Network
And check out:
NAMN home page:
http://web.infoavedot net/~meteorobs
Back issues of NAMN Notes can be found on-line at the NAMN website, and in
the meteorobs archives at:
http://www.tiacdot net/users/lewkaren/meteorobs
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:
owner-meteorobs@jovian.com
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Here's to 'Clear Skies' for October...
October 2000 NAMN Notes written
by Cathy Hall
(with congrats to Mark and Dawn Davis off on their wedding trip!)
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