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. February - The Doldrums of Winter...
2. Alpha-Centaurids, a Southern Alert...
3. Other February Activity...
4. Upcoming Meetings...
5. For more info...
Welcome to February! It is now the dead of winter for those of us in northeastern North America, and we are yearning for clear skies. We have had warmer than normal temperatures for some time now - and lots of cloud. Traditionally, clear skies up here mean about -20C. This winter, some days were so mild you didn't even need a winter coat.
However, it's a great time of year to dream about summer, and southern latitudes, and observing projects to have fun with once you see the stars again.
Have you printed yourself off a copy of the International Meteor Organization's 2006 Meteor Shower Calendar yet? It's free, just print it off from http://www.imo.net/calendar/2006
Go cruising around the IMO website at http://www.imo.net. There are sections on many different types of observing - visual, telescopic, photographic, video and radio. Need a change this year? Check out a different way to observe meteors - and still help out the researchers.
Want to meet some of the meteor observers from around the globe and get an interesting vacation as well? The IMO is holding its annual get-together in the Netherlands this coming September. Specific details will be on the IMO website once they become available. Take a trip to Europe... and take in some science and some camaraderie while you're at it.
Need some ideas on something completely different? Go cruising through the meteor/meteorite/comet/impact links at http://www.snark.org/sb.htm. For endless cloudy nights, it's a cool site.
February won't last forever - or so the ground hogs tell us. I wonder if it's only North Americans who believe in telling when spring will come by the behavior of small rodents...
Clear skies to all!
The alpha Centaurids (ACE) peak on February 8th this year, and can be seen through until about February 21st. These are fast meteors, with a velocity of about 56 km per second. ZHR rates are variable. The rates are usually about 6 meteors per hour, but outbursts of 20 to 30 per hour have occurred. Many of the alpha Centaurids are very bright, even fireballs.
For new observers, ZHR refers to Zenithal Hourly Rate, and is the average number of meteors that an observer would expect to see in an hour, if they are out under dark country skies, and if the radiant, the area in the sky where the meteors seem to come from, is directly overhead, at the zenith.
This is primarily a southern shower though, with a radiant location of about -59 degrees on a star map, about 50 degrees south of the bright star Spica in Virgo. Check out a map on the website of the IMO at http://www.imo.net/calendar/2005/winter
All observers in southern latitudes are encouraged to get out and gather observations of this shower. The IMO writes: "As with many southern hemisphere sources, we have more questions than answers at present, nor do we have any means of telling when, or if, another stronger event might happen. Thus photographic, video and visual observers are urged to be alert..."
Although not on the official IMO 'Working List of Visual Meteor Showers', a watch should be kept for any possible xi Bootids. These were first seen by observer George Gliba from February 5/6 to 8/9 in 1997 from the Florida Keys. These were noted as medium velocity meteors, with an average magnitude of about 3.6 and a radiant near the star xi Bootes. Xi Bootis is about 8 degrees to the left of the star Arcturus on a star map.
The delta Leonids (DLE) peak on February 24th, and can be seen from about February 15th to March 10th. These are slow meteors, at about 23 km per second, so will be quite distinctive. ZHR rates at the peak will be about 2 meteors per hour. The radiant will be very close to the star theta Leonis, the lower right star in the triangle at the end of Leo. For a map, check out http://www.imo.net/calendar/2006/winter
The gamma Normids (GNO) start to become active about February 25th, although won't reach a maximum until about March 13th. These are fast meteors, with a velocity of about 56 km per second. ZHR rates at maximum will be about 8 meteors per hour, but rates in February will be lower. With a radiant about 30 degrees south of the top of the 'J' of Scorpius, this is primarily a southern shower. A map showing the radiant can be found at http://www.imo.net/calendar/2005/winter
The Virginids (VIR) started to become active about January 25th, and last until about April 15th. These are almost slow meteors, at about 30 km per second. ZHR rates are about 5 meteors per hour. On January 30th, the radiant was at 157 degrees, ie. RA 10h 28.2m, Dec +16, which was about 6 degrees up to the left of Regulus in Leo on a star atlas. The radiant moves throughout the month of February - positions at intervals are as follows:
Feb. 10 165 +10 ie. RA 11h 00m Dec +10 Feb. 20 172 +6 ie. RA 11h 28.2m Dec +6 Feb. 28 178 +3 ie. RA 11h 52.2m Dec +3
For other minor showers not on the IMO's 'Working List of Visual Meteor Showers', and for a wealth of historical information on all showers, check out Gary Kronk's 'Comets and Meteor Showers' website at http://comets.amsmeteors.org
Besides February's main activity and other minor showers, there is also sporadic meteor activity. This sporadic meteor activity is about 7 meteors per hour visible to the unaided eye. Some of these are random, and some belong to old untraceable meteor showers.
If you want to record visual data 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. If you have any questions, drop a note to our NAMN Coordinator at meteors@comcast.net
NAMN has some good star charts to mark your radiants on before you go out observing. These charts also show constellations for the whole sky and give the brightness of a number of stars to use in judging the magnitude of the meteors you see. Our 4 printable charts can be found at http://www.namnmeteors.org/charts.html. Set your printer to 'landscape' mode.
Forms to record your observations can be found at http://www.namnmeteors.org/namn_form.html and http://www.namnmeteors.org/appendixC.html
Planets at midmonth, and their magnitudes, for northern observers, are:
Venus -4.5 very low in east-southeast morning twilight Jupiter -2.1 in Libra Mercury -1.1 very low in west-southwest evening twilight Saturn -0.2 in Cancer Mars 0.4 in Taurus
For 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'. On February 6th, the moon will be 0.1 degree north of the Pleiades star cluster. On the 16th, Mars will be 2 degrees south of the Pleiades.
There are several interesting occultations this month. On the 18th, the bright star Spica will be 0.4 degrees south of the moon, with an occultation visible from extreme eastern North America, and central Africa. On the 21st, the star Antares will be 0.2 degrees north of the moon, with an occultation visible from Indonesia, Australia except the northeast, and New Zealand. And lastly, on February 25th, the asteroid Ceres will be 0.8 degrees north of the moon, with an occultation visible from the tip of South America, and Antarctica. (An occultation of Ceres would be really cool to watch, in more ways than one!)
The phases of the moon for February are as follows:
Sun. Feb. 5 first quarter Mon. Feb. 13 full moon Tues. Feb. 21 last quarter Tues. Feb. 28 new moon
For a great printout of moon phases for the month, check out http://stardate.org/nightsky/moon
June 8-14, 2006, Ostersund, Sweden...
The Workshop on Impact Craters as Indicators for Planetary Environmental
Evolution and Astrobiology will be held in Ostersund, Sweden. Sessions
include terrestrial craters, craters on other planetary bodies, the
influences of the impact on the target area, the target area on the fate of
the projectile, and the properties of the impactor on the cratering process,
other consequences (eg. tsunamis), environments created by the impact and
their importance for life, and astrobiological aspects of impact cratering.
There will be two study field trips to the Lockne Crater, and an excursion
to the GeoCenter-Lockne Impact Crater Museum. For information, check out
the website at
http://www.geo.su.se/Lockne2006 and contact Dr. Jens Ormo of
the Planetary Geology Laboratory, CSIC/INTA, Madrid, Spain at ormo@inta.es
July 10-14, 2006, Singapore...
The AOGS, Asia Oceania Geosciences Society, will hold its 3rd Annual Meeting
in Singapore. Jeremie Vaubaillon has advised us that there will be a
special session on the field of meteor science. Topics covered at the
conference are quite varied - invited speakers include G. Consolmagno of the
Vatican Observatory on 'Evidence from Meteorites', Cheng Fang of Nanjing
University on 'Spectroscopic Approaches to Solar Flares: A Review', Paul
Jones of the Australia Telescope National Facility on 'Radio Observations
from Australia of Comet 9P/Tempel 1 for Deep Impact', and Dave Anderson of
NOAA on 'Solar Activity and Indian Monsoons'. The deadline for abstract
submission is February 15th. The deadline for reduced fees for registration
is May 15th. For information, check out the website at
http://www.asiaoceania-conference.org and contact
info@asiaoceania-conference.org
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
Ottawa, Ontario, Canada
Writer, NAMN Notes
Lew Gramer, dedalus@alum.mit.edu
Homestead, Florida, 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