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. Welcome to Summer!...
2. Summer and the Aquarids...
3. Other July Activity...
4. Upcoming Meetings...
5. For more info...
Well, summer has finally arrived - along with our monthly meteor notes on shower activity! It has been a busy time for our meteor crew as well, with a number of us packing, moving and getting settled into new locations around the country. This has resulted in some small delays, but we know those of you who have gone through this will understand.
For this Canadian observer, this has meant a move back into the city - but a savings of over 3 hours a day commuting from the countryside in and out to work every day. Although an urban setting, I now have a beautiful unobstructed eastern horizon from north all the way through to south, overlooking the Ottawa River and the Gatineau Hills from a quite respectable height. The other night I was stretching back in bed - and the ISS, the International Space Station - went right across my window. Wall to wall windows are very enjoyable! The crescent moon rose beautifully over Canada's Parliament Buildings the other morning, and Mars is getting higher in the sky every day. As I overlook an older section of the city, it is covered with large mature trees, and I have just a minimum of sodium lighting to contend with. For the first time in months, I am actually rediscovering my sky...
Summer also brings friends and opportunities to get together in the warm weather. July 1st was Canada's national holiday, and I joined up with Pierre Martin and his observing group for a star party and fireworks celebration the evening before. For those of you who know Pierre, he lives and breathes meteors! The fireworks display that he coordinated was no exception. Every firework, every special display, must have been chosen with meteors in mind... and a very good sense of humor! Meteors swirled out from imaginary radiants and made little 'zinging' noises as they flew... larger meteors in all colors broke from higher radiants and showered us all... exploding meteors broke into pieces and emitted loud 'bangs'... showers of meteors flew and 'hissed' at us! I have never enjoyed a fireworks display that had so many unusual visual effects - or so many different and absolutely hilarious noises! Well done, Pierre!
We wish you all a great summer, clear skies, and many natural meteors to observe and enjoy wherever you are!
What do we have for the summer? Well, we have lots and lots of Aquarid meteors on the agenda. We have the northern and southern delta Aquarids, and the southern iota Aquarids, for July.
In fact, it's a good idea to print yourself off some of our NAMN star charts to mark all these showers on ahead of time, before you go out observing. Set your printer to landscape mode, and grab the 4 charts from http://www.namnmeteors.org/charts.html. They show constellations, RA and Dec (our grid lines in the sky), and give the brightness of a number of stars to use in judging the magnitude of the meteors you see.
The southern delta Aquarids (SDA) reach a maximum on July 28th, with a radiant at 339 degrees, ie. RA 22h 36m, Dec -16, which is about 5 degrees to the right of the star delta Aquarius. These are average velocity meteors, at about 41 km/sec, and can be seen from about July 12th to August 19th. At the peak on the 28th, ZHR rates are about 20 meteors per hour.
What is ZHR? This is Zenithal Hourly Rate, and is the number of meteors, on the average, that an observer would expect to see in an hour if the radiant, the area in the sky where the meteors seem to come from, is directly overhead - and if an observer is out under dark country skies. If the radiant is not overhead, you will see less. If your sky is not really dark, you will see less. So - to see as many meteors as possible, get away from city lights, and try to observe when the shower radiant is higher in the sky.
The southern iota Aquarids (SIA) reach a peak on August 4th, but can be seen from about July 25th to August 15th. These are slower than the delta's, with a velocity of about 34 km/sec, but still classed as 'average' velocity. At maximum on August 4th, their ZHR will be about 2 meteors per hour. Rates in July will be less. On July 25th, their radiant will be at 322 degrees, ie. RA 21h 28.2m, Dec -17.
The northern delta Aquarids (NDA) reach a peak on August 8th, but again, can be seen starting in July, as they run from about July 15th to August 25th. These are average velocity meteors at 42 km/sec, very similar to the southern delta's. At their peak on August 8th, they will reach a ZHR of about 4 meteors per hour, but rates in July will be lower. On July 25th, their radiant will be at 323 degrees, ie. RA 21h 31.8m, Dec -9.
The IMO, the International Meteor Organization, has maps showing all these radiants at http://www.imo.net/calendar/cal05.html#aquarid-capricornid. There is also a simple way to keep track of these 3 showers, and the northern iota Aquarids coming in August. If you look at these 4 Aquarid radiants on any given night, they form a sort of parallelogram in the sky. However, plotting is useful when observing these meteors - and recommended.
If you want to record data on these showers 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
Forms to record your observations can be found at http://www.namnmeteors.org/namn_form.html and http://www.namnmeteors.org/appendixC.html
The summer sky is a busy one. Besides the Aquarid complex, there are a lot of other assorted showers to observe - and it can be quite a challenge remembering all the radiants!
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 - and fireballs are possible. Coordinates for July are as follows:
July 5 289 -22 ie. RA 19h 16.2m Dec -22 July 10 293 -22 ie. RA 19h 31.8m Dec -22 July 15 298 -21 ie. RA 19h 52.2m Dec -21
The June Bootids (JBO), although peaking in late June, are visible until about July 2nd. These are slow meteors, with a velocity of about 18 km/sec. ZHR rates are variable. A map showing the radiant is available at http://www.imo.net/calendar/cal04.html#June-Bootids
The Pegasids (JPE) reach a maximum about July 9th, but can be seen from about July 7-13. These are fast meteors, with a velocity of about 70 km/sec. The radiant at maximum will be at 340 degrees, ie. RA 22h 40.2m, Dec +15, which is about 4 degrees north of the star zeta Pegasus. ZHR rates at max are about 3 meteors per hour. A map of the radiant can be found at http://www.imo.net/calendar/cal05.html#pegasids. According to the IMO, 'swift, faint meteors can be expected, favoring telescopic observing'.
The July Phoenicids (PHE) reach a maximum about July 13th, and can be seen from about July 10-16. These are average velocity meteors at about 47 km/sec. The radiant at maximum will be at 032 degrees, ie. RA 2h 7.8m, Dec -48, which is about 27 degrees due south of the star upsilon Cetus, the left foot of Cetus. This shower is better observed by southern observers. ZHR rates are variable, about 3-10 meteors per hour. For a map, check out http://www.imo.net/calendar/cal05.html#july-phoenicids. Observations are really needed for this shower to learn more about it!
The Pisces Austrinids (PAU) peak about July 28th, but can be seen from about July 15th to August 10th. These are average velocity meteors at about 35 km/sec. The radiant at the peak will be at 341 degrees, ie. RA 22h 43.8m, Dec -30, which is about 3 degrees to the right of alpha Pisces Austrinus, the star known as Fomalhaut. ZHR rates are about 5 meteors per hour at maximum. For a map showing the movement of the radiant, check out http://www.imo.net/calendar/cal05.html#piscis-austrinids
The alpha Capricornids (CAP) peak about July 30, and range from about July 3rd to August 15th. These are wonderful, slow meteors, with a velocity of about 23 km/sec. On July 30th, at maximum, the radiant will be at 308 degrees, ie. RA 20h 31.8m, Dec -10, which is about 4 degrees up to the left of the star alpha Capricornus, the top right star of the triangle of Capricornus. ZHR rates at the peak are about 4 meteors per hour. For movement of the radiant, check out the map on the IMO website at http://www.imo.net/calendar/cal05.html#alpha-capricornids. According to the IMO, in their 2005 Meteor Shower Calendar, 'the alpha-Capricornids are noted for their bright - sometimes fireball-class - events, which, combined with their low apparent velocity, can make some of these objects among the most impressive and attractive an observer could wish for'.
Lastly, although observers tend to think of Perseids (PER) as an August shower, they start to become active about July 17th. They run through until about August 24th, with a peak around August 12th. These are fast meteors, with a velocity of about 59 km/sec. ZHR rates around August 12th will be about 100 meteors per hour. Rates in July will be much lower. This shower lasts a long time - and the radiant moves quite a distance across the sky, a little bit each night. Check out this movement on the IMO chart at http://www.imo.net/calendar/cal05.html#perseids
Besides July'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.
Planets at midmonth, and their magnitudes, for northern observers, are:
Venus -3.8 very low in west-northwest in evening twilight Jupiter -2.0 in Virgo Mars -0.2 in PiscesFor 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'.
The phases of the moon for July are as follows:
Wed. July 6 new moon Thurs. July 14 first quarter Thurs. July 21 full moon (largest of 2005) Thurs. July 28 last quarter
For a great printout of moon phases for the month, check out http://stardate.org/nightsky/moon. On Monday July 18th, at 4h UT, the star Antares will be 0.6 degrees south of the moon, with an occultation visible from the northeast Pacific Ocean, the southern and western USA, the Caribbean, and northern South America.
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. 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
July 1st (130 EUR after), and includes all accommodation, all meals, and the
conference registration. Financial assistance is available in some cases.
There will be a guest lecture by Prof. Dr. Philippe Claeys on meteorite
impacts. For information on the conference, check out
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
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