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(meteorobs) NAMN Notes: June 2000



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NAMN Notes: June 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. June Showers...
2. Help for New Observers...
3. Limiting Magnitude Calculator...
4. NAMN Member Finds 4 Comets in May!...
5. Upcoming Meetings...
6. For more info...


1. June Showers...

For the month of June, there are only a couple meteor showers on the 2000
Working List of the IMO, the International Meteor Organization. These are
the showers that NAMN observers will concentrate on for this month.

The ecliptic activity continues to be the Sagittarids (SAG), the activity
whose radiant travels along the path of the ecliptic. These are slow
meteors, with a velocity of about 30 km per second. The Zenithal Hourly
Rate, ZHR, for this activity is about 5 meteors per hour. This means that if
an observer is out under a pitch black sky, with the radiant, the area in
the sky where the meteors seem to come from, directly overhead, then that
observer should see, on the average, about 5 meteors each hour with the
unaided eye.

At the beginning of the month, the IMO lists the radiant as being at 256
degrees, ie. RA 17h 4m, Dec -23, which is about 8 degrees up to the left of
the reddish star Antares. On June 10th, the radiant will have moved to 265
degrees, ie. RA 17h 40m, Dec -23, and by month's end on June 30th, the
radiant will be at 284 degrees, ie. RA 18h 56m, Dec -23, about 3 degrees
north of the star sigma Sagittarius, better known as Nunki. Fireballs are
possible with this shower, so observers are often rewarded for their
observations.

The June Bootids (JBO) are a new addition to the IMO Working List for this
year, and reach a maximum on June 27, with a radiant at 224 degrees, ie. RA
14h 56m, Dec +48, about 7 degrees north of the star beta Bootes, also known
as Nekkar. Meteors can be seen from about June 26 to July 2nd. They are
slow, with a velocity of about 18 km per second. Rates are variable, and all
information on this shower will be very much appreciated! The shower's
parent body is Comet 7P/ Pons-Winnecke.

There are some other showers visible this month, but only the ones just
mentioned are on the IMO Working List for this year. Why? These other
showers are very minor, and are probably of interest only to very serious or
experienced observers who are usually dedicated to plotting meteors over
long periods of time, or who are using methods other than the visual
recording of meteors. A dependable minor shower is one with at least about 3
meteors per hour, so the following very minor showers, with fewer meteors
than that, are only evident over long periods of observing!

If you have gained some experience, and would like to try plotting meteors
to study some minor showers, email the NAMN Coordinator at
MeteorObs@charlestondot net for some special plotting maps to mark your meteors
on.

For those of you who may be interested, these very minor showers are as
follows, as taken from the March 2000 issue of the American Meteor Society
publication "Meteor Trails":

Omega Scorpiids (OSC), with a maximum on June 2nd, radiant at RA 15h 56m,
Dec -20, velocity 21 km/sec, weak minor shower.

Arietids (DAR), with a maximum on June 7th, radiant at RA 2h 56m, Dec +24,
velocity 38 km/sec, weak
minor shower.

June Lyrids (JLY), with a maximum on June 16th, radiant at RA 8h 32m, Dec
+35, velocity 31 km/sec, shower with irregular rates.

Tau Cetids (CET), with a maximum on June 27th, radiant at RA 1h 36m,
Dec -12, velocity 66 km/sec, weak minor shower.

Tau Aquarids (TAQ), with a maximum on June 28th, radiant at RA 22h 48m,
Dec -12, velocity 63 km/sec, weak minor shower.

Theta Ophiuchids (TOP), with a maximum on June 29th, radiant at RA 16h 36m,
Dec -15, velocity 29 km/sec, weak minor shower.


2. Help for New Observers...

Welcome to NAMN - the North American Meteor Network! We are now up to 193
members worldwide, and our goals are to recruit amateurs as meteor
observers, train them in the methods of meteor observation, and coordinate
North American observations. If you have any questions at any time, drop us
a note at MeteorObs@charlestondot net

If you are new to observing this spring, check out the beginning star charts
that NAMN has posted to the website. These are a set of four, and show all
the constellations for northern latitude observers with star brightness
('magnitude') marked on the chart for selected stars that can be used to
help in judging the brightness of the meteors you see. The charts are
labeled in the margin with the equivalent of 'latitude' and 'longitude' in
the sky, so you can figure out where the various meteor radiants are
located. Set your printer to 'landscape' mode, and print yourself off a set
at http://web.infoavedot net/~meteorobs/charts.html

For help in what to record, check out our NAMN Observing Guide. It has easy
to read chapters on all the basics of meteor observing. It can be read
onscreen, or printed off your computer, at
http://web.infoavedot net/~meteorobs/guide.html

There are of course, many things moving around the sky this month, besides
just meteors! If you want to find out what satellites you can see while
you're out meteor observing, check out http://www.heavens-above.com Keeping
an eye out for satellites is not only fun, but can also give you practice in
estimating the brightness of moving objects - and help keep you alert during
periods of lesser activity.

New moon this month is on June 2nd, 1st quarter on June 9th, full moon on
June 16th, and last quarter on June 25th. It is always preferable to try to
get out observing when the moon is not causing too much light interference
in the sky - a brighter sky means that you will not see as many meteors.


3. Limiting Magnitude Calculator...

Limiting magnitude (LM) is a measure of the faintest star an observer can
see on a particular night, and is used by the meteor organizations to help
adjust data from many observers to a common base for comparison of meteor
rates. It is important for all observers, new and experienced, to make an
estimate of this LM about every half hour when you are out observing.

Luckily, this isn't difficult. The International Meteor Organization has
developed a number of areas in the sky to use for star counts. Some are
triangles, some are four-sided areas. Triangles are easiest - you just count
all the stars you can see in that triangle, including the corner stars, and
then look at the IMO table. You read across the line from your 'star count'
to get the 'magnitude' of the faintest star that you have seen. You don't
need to worry about that while you are counting though - you just count
stars, and the table gives you the LM, the limiting magnitude number.

Most observers so far have just ordered copies of the star count charts from
the IMO and keep these in their observing bag to take out with them. After
all, when you're out in your lawnchair, you need some maps to know where the
triangles are. These star count charts are available free of charge by
sending a stamped, self-addressed envelope to Mr. Robert Lunsford, IMO
Secretary-General, 161 Vance Street, Chula Vista, CA 91910. If you wish a
copy of the Atlas Brno as well, on which these are based, include a money
order for $4 US, payable to Robert Lunsford.

However - recently a new tool has been added to the NAMN website, to give
you the option of just printing off the essential maps of the star count
areas that you will need on a given night. The "Limiting Magnitude Field
Locator and Calculator" was kindly provided by Peter Girard of ESRI-Boston,
a company that markets geographic information systems (GIS) software.

This tool utilizes the predefined star count areas published by the
International Meteor Organization, and provides three different fields to
use during an observing session. Optionally, it can be used to determine the
limiting magnitude by entering the number of stars counted in the field.
This results in the limiting magnitude for that field being displayed
onscreen. Finally, the webpage also generates the average limiting magnitude
for fields that are used.

Observers are encouraged to check out the "Limiting Magnitude Field Locator
and Calculator" at the home page of the North American Meteor Network:
http://web.infoavedot net/~meteorobs


4. NAMN Member Finds 4 Comets in May!...

Michael Boschat, a NAMN member in Halifax, Nova Scotia, Canada has found 4
more comets this month by studying the images from the SOHO satellite!
Congratulations Mike!

What is SOHO? SOHO stands for the Solar and Heliospheric Observatory, and is
an orbiting spacecraft that observes the sun 24 hours a day. It is a
cooperative mission between ESA, the European Space Agency, and NASA, the
National Aeronautics and Space Administration. It has specialized
instruments to study a number of aspects of the sun - the solar interior,
the solar corona, and the solar wind.

The images that Mike and others have been analyzing to find comets are
generated by a special instrument on the spacecraft - the LASCO, Large Angle
Spectrometric Coronagraph. Basically, it's a wide angle instrument that
takes images of the area around the sun, with the sun itself blocked out.
Hence we are able to see, among other things, comets very near the sun,
invisible to normal telescopes. The wide angle images being used in these
comet discoveries are the LASCO C2 and C3 images.

Check out the website showing the SOHO pictures of the sun at
http://sungrazer.nascom.nasadot gov The 'EIT' images show the sun up close and
personal. They show the surface of the sun, and below the surface, at a
variety of different wavelengths.

The orange 'C2' images and the blue 'C3' images are the very wide angle
shots with background starfields and comets. The real-time full color movies
on this site are absolutely incredible! You can see the sun moving through
starfields on the C3 images, with gases and material being thrown off as it
travels along, and you can see all kinds of other moving objects on the
images - including the occasional comet! Each movie takes a number of
minutes to download (on a fast modem), but is really worth the wait! Check
out the current wide angle C3 movie at
http://lasco-www.nrl.navy.mil/mpg/current_c3.gif

Details of Mike Boschat's May comet finds are as follows, and are listed
under 'What's New' on the SOHO website:

Confirmed May 10th: Mike's 3rd comet, a co-discovery of SOHO-114
(Kreutz-100), a sungrazing comet, with K. Cernis, visible in the LASCO C3
data, passing just to the left of Saturn on the images late in the day on
May 9th.

Confirmed May 22nd: Mike's 4th comet, discovery of SOHO-116, a Kreutz
sungrazing comet, visible in the LASCO C2 data beginning at 2126 UT on May
19th.

Confirmed May 26th: Mike's 5th comet, a co-discovery of SOHO-119, a
sungrazing comet, with M. Oates, visible in the LASCO C2 data beginning at
2306 UT on May 25th, with little or no tail evident.

And... confirmed on May 30th: Mike's 6th comet, jointly with M.Oates and
X.Leprette, SOHO-120, a Kreutz comet visible in the LASCO C2 data at the
beginning of the day on May 27, no tail evident... In Mike's own words in an
email to Mark Davis on May 30th: "From Doug at Goddard... official now :))))
Mike"

Check out Mike's homepage at: http://www.mscs.daldot ca/~andromed It gives
details of his other astronomical interests - and also has probably the best
list of astronomical links anywhere!


5. Upcoming Meetings...

July 9-12, 2000 - Austria:
The international conference 'Catastrophic Events and Mass Extinctions:
Impacts and Beyond' will be held at the University of Vienna in Austria.
This is the 4th in a series of meetings on mass extinctions and global
catastrophes, the previous meetings being 1981 and 1988 in Utah, and 1994 in
Houston, Texas. Expected topics include impact events in earth history,
boundary events in geologic time, environmental consequences of impacts,
interpretation of stratigraphic records, and extraterrestrial influences suc
h as asteroids and comets. More information on the conference can be found
at:
http://www.lpi.usradot edu/meetings/impact2000/impact2000.2nd.html

July 25-August 4, 2000 - Slovenia:
An International Astronomical Camp, IAC 2000, will be held in the Pohorje
Mountains at Mariborska koca (MBK), Slovenia. Work will be divided into
various groups - Solar System, Meteors, Deep Sky, Variables and double
stars, and Astrophotography. For more information, contact Jure Zakrajsek by
email at elizabeta.zakrajsek@guest.arnesdot si

September 11-15, 2000 - Crimea:
The international conference 'Space Protection of the Earth - 2000' will be
held in Evpatoriya in the Crimea. This is the 3rd in a series of
international conferences on the protection of the Earth from the threat of
its collision with asteroids and comets, with the prior meetings being held
in Saint Petersburg and Snezhinsk, Russia. Topics will cover characteristics
of asteroids and comets, their risk, detection technologies, man-made means
of influencing dangerous celestial bodies, planetary defense, international
cooperation, prospects for utilizing asteroid and comet resources, and other
issues. For more information, contact the SPE-2000 Program Committee by
email at: spe@asteroids.ru

September 21-24, 2000 - Romania:
The IMC, International Meteor Conference, of the IMO, the International
Meteor Organization, is being held in Pucioasa, Romania, about 100 km
northwest of Bucharest. It is being organized by the Romanian Society for
Meteors and Astronomy (SARM), in cooperation with the mayoralty of Pucioasa.
Pucioasa can be reached by direct trains and buses from Bucharest, and a
shuttle bus from the Bucharest airport to the conference site is planned.
Accommodation will be provided in double rooms, and meals served at the
restaurant of the hotel close to the conference site. The conference fee
will be 170 DEM. A deposit of at least 100 DEM is requested for those
interested in attending, and a registration form is on the IMO website at
www.imodot net.


6. 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

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

June 2000 NAMN Notes co-written
by Mark Davis and Cathy Hall
======================================




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