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
1. Eta Aquarids - Halley's Debris...
2. Other May Showers...
3. Upcoming Meetings...
4. For more info...
The eta Aquarids (ETA) are the highlight of the month of May - and hopefully bring good weather to you all!
These meteors can be seen from about April 19th through to May 28th, and reach their highest rates on May 5th at about 24h UT according to the IMO, the International Meteor Organization. Note however that, regardless of the time of maximum activity, you must wait until the morning hours when Aquarius starts to rise, if you are observing visually! Radio observers will be able to make observations even in daylight hours.
ZHR rates for this shower are about 60 meteors per hour, although the rates are periodically variable from about 40 to 85 meteors per hour. What is ZHR? This stands for Zenithal Hourly Rate, and is the number of meteors that an observer would expect to see in an hour, on average, 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.
Where is the radiant? Check out the map on the IMO website at http://www.imo.net/calendar/cal05.html#eta-Aquarids to see where the meteors will be coming from on any given night. The radiant moves a fair distance over the shower's timeline.
According to the IMO, in their 2005 Meteor Shower Calendar:
"This is a fine, rich stream associated with Comet 1P/Halley, like the Orionids of October, but it is visible for only a few hours before dawn... The fast and often bright meteors make the wait for radiant-rise worthwhile, and many events leave glowing persistent trains after them. While the radiant is still low, eta-Aquarid meteors tend to have very long paths..."
"A relatively broad maximum, sometimes with a variable number of submaxima, usually occurs in early May... IMO analyses in recent years... have shown that ZHRs are generally above 30 between about May 3-10, and that the peak rates appear to be variable on a roughly 12-year timescale. The next highest rates should fall towards 2008-2010, if this Jupiter-influenced cycle is borne-out. Visual ZHRs should thus be around 50-60 in 2005, according to this idea..."
The eta Aquarids are fast meteors at about 66 km per second - and are well worth getting up for in the early morning hours in May. The opportunity to see debris from Halley's Comet is something special for both casual and serious observers alike!
If you want to record data on this shower 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@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
The Sagittarids (SAG) started to become active about April 15th and will last through until about July 15th. These are almost slow meteors, at about 30 km per second. ZHR rates are about 5 meteors per hour. Coordinates for the radiant in May are as follows:
May 05 236 -20 ie. RA 15h 43.8m Dec -20 May 10 240 -21 ie. RA 16h 00.0m Dec -21 May 20 247 -22 ie. RA 16h 28.2m Dec -22 May 30 256 -23 ie. RA 17h 04.2m Dec -23
Besides May'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.
For radio meteor observers, the epsilon Arietids peak on May 9th, the May Arietids on May 16th, and the omicron Cetids on May 20th. For more information on radio observing, check out the IMO website at http://www.imo.net
Planets at midmonth, and their magnitudes, for northern observers, are:
Venus -3.8 low in west-northwest in evening twilight Jupiter -2.3 in Virgo Saturn 0.2 in Gemini Mars 0.5 in AquariusFor a sky chart showing the positions of all the planets visible this month, go to http://www.heavens-above.com, select your country, then your city, and go to 'Whole Sky Chart'.
This month, the phases of the moon are as follows:
Sun. May 1 last quarter Sun. May 8 new moon Mon. May 16 first quarter Mon. May 23 full moonFor a great printout of moon phases for the month, check out http://stardate.org/nightsky/moon
August 7-12, 2005, Brazil...
ACM 2005, the IAU Symposium 229: Asteroids, Comets, Meteors, will be held
in Rio de Janeiro, Brazil. The main topics of the conference will be space
missions, internal structure of asteroids and comets, connections between
asteroids, cometary nuclei and Trans-Neptunian Objects (TNO's), connections
between asteroids and meteorites, connections between comets, meteor showers
and interplanetary dust, minor body dynamics, collisions and impacts,
Near-Earth Objects (NEO's), origin and evolution of our Solar System and
extra-solar planetary systems. The website for the conference is at
http://www.on.br/acm2005.
For more information, contact Daniela Lazzaro or
Fernando Roig at acm2005@on.br
September 10-14, 2005, Belgium...
'Radio Meteor School 2005' will be held in Oostmalle, Belgium. This will be
a five day tutorial on the physical and mathematical theory of radio meteor
observations, given by Dr. Oleg Belkovich of Russia. This workshop is for
serious radio meteor observers. The cost for the workshop is about 150
Euros. You must register before July 1st. For more information, check out
the IMO website at
http://www.imo.net/imc2005/radioschool.php and contact
the organizers at imc2005@imo.net
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 before
June 1st (130 EUR after), and includes all accommodation, all meals, and the
conference registration. Financial assistance is available in some cases.
For information, check out the conference website at
http://www.imo.net/imc2005.
For questions, contact Jan Verbert at
imc2005@imo.net
For information on upcoming astronomy meetings, see: "International Astronomy Meetings List" at http://cadcwww.hia.nrc.ca/meetings
NAMN email: namn@namnmeteors.org
NAMN website: http://www.namnmeteors.org
Mark Davis, meteors@comcast.net
Goose Creek, South Carolina, USA
Coordinator, North American Meteor Network
Cathy Hall, chall@cyberus.ca
Metcalfe, Ontario, Canada
Writer, NAMN Notes
Lew Gramer, dedalus@alum.mit.edu
Medford, Massachusetts, USA
Coordinator, Public Outreach
Owner/Moderator, 'MeteorObs'
Kevin Kilkenny, namnfireball@earthlink.net
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.mit.edu