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(meteorobs) NAMN Notes: February 2001
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NAMN Notes: February 2001
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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. The Showers of February...
2. Make a Plan for 2001...
3. Learning Tools for Meteor Observing...
4. Upcoming Meetings...
5. For more info...
1. The Showers of February...
February is a very quiet month for both major and minor showers.
The delta Leonids (DLE) reach maximum activity on February 24th, but can be
seen from about February 15th until March 10th. At maximum, the ZHR rate is
about 2 meteors per hour. This is the expected number that will be seen
under dark country skies, if the radiant, the area in the sky where the
meteors seem to come from, is directly overhead. The radiant is located at
168 degrees, ie RA 11h 12m, Dec +16, which is very near the star theta
Leonis, the lower right star in the triangle at the end of Leo. These are
slow meteors, with a velocity of about 23 km/sec.
There are several showers visible in the southern hemisphere during this
period - and it is possible members of these may be seen from the southern
areas of North America.
The alpha Centaurids (ACE) reach a maximum on February 8th, and run until
about February 21st. At maximum, the radiant is at 210 degrees, ie. RA 14h
00m, Dec -59, which is very near the star beta Centaurus - approximately 35
degrees down to the right of the constellation of Libra, for those not
familiar with this constellation. These are fast meteors, with a velocity of
about 56 km/sec. The ZHR rate is about 6 meteors per hour at maximum.
The gamma Normids (GNO), another southern shower, do not reach a maximum
until March 13th, but some members of the shower can be seen from about
February 25th on. The radiant on the 28th will be at 234 degrees, ie. RA 15h
36m, Dec -52, which is about 4 degrees to the left of the star zeta Lupus,
about 30 degrees south of the top of the 'J' of Scorpius. These are fast
meteors, at about 56 km/sec. At maximum in March, the ZHR rates will reach
about 8 meteors per hour. The rates in late February will be lower.
Are these the only meteors visible in February? No. There are always more
minor showers visible, with extremely low rates of perhaps only a meteor
visible over hours. Also - and this is important - there is always sporadic
meteor activity visible each night. These are meteors which cannot be
connected to current known shower activity, or perhaps belonged to showers
visible hundreds of years ago, which we have lost track of. With the unaided
eye, these sporadic meteor rates can reach about 7 meteors per hour - and
help fill in the time gap between sightings of shower meteors such as the
delta Leonids this month.
2. Make a Plan for 2001...
Have you considered doing up an observing plan for 2001? Maybe you are new,
or just a casual observer, but actually thinking out a plan for the coming
year has lots of benefits!
There is a saying: "If you don't know where you are going, you'll probably
never get there!" This is very true. Think ahead now, about what you would
like to have accomplished by this time next year.
If you are new, perhaps your goal for this year might be to learn all the
constellations visible from your location, and observe several of the major
showers - the Perseids and the Leonids, for example.
If you have learned the basics of major shower observing, perhaps your
observing plan for this year might be learning how to plot meteors for minor
showers. There are many minor meteor showers that the International Meteor
Organization (IMO) could really use information on. Plotting meteors over
several hours the nights you are out is very valuable - it might even detect
some new meteor showers! The more meteors plotted over a number of nights,
the more valuable your data will be.
Do you want to set a goal of a number of nights observing for 2001? Maybe
you only managed to get out a handful of evenings in 2000, and your goal is
higher for 2001. Get out a calendar. Mark on the new moon dates and the
dates of the big showers. Plan ahead if you want to use some of your
holidays in order to observe - either from your local area or from a dark
sky site or the location of some summer star party.
Do you want to try something different this year - like observing meteors
through a telescope instead of with the unaided eye? This is another field
that could use observers. Because the field of view is small, this has its
challenges - but can help define meteor radiants to greater accuracy.
Similarly, do you want to try photographic or video detection of meteors?
These are not simple pursuits, and are equipment intensive. However, if you
are inclined towards technical projects, these could be for you!
Whatever your particular observing interests - be they at the beginning or
more advanced level - set yourself a plan for the year! You will get a
feeling of accomplishment as you learn new things, and work your way through
your own personal list of meteor goals for 2001!
3. Learning Tools for Meteor Observing...
Are you new to meteor observing? Do you wonder what is involved, how you
could possibly help out the meteor community, and what you should record?
There are many learning tools available to help you find out more about
meteors and observing. Some of these relate to observing the sky in general,
and others relate specifically to meteors.
If you want to go out under the night sky and record meteors, it really
helps to learn the constellations. There are many observers who use
telescopes to look at planets, galaxies and star clusters - who do not know
their constellations! They might know their way around the sky by 'RA' and
'Dec' - Right Ascension and Declination, the coordinates used by their
computerized telescope tracking system - but they can' t recognize the
constellation of Virgo! For meteor observing, you have to learn your
constellations.
Several good atlases for meteor observing are Norton's 2000.0 Star Atlas,
and the lower priced Tirion's Bright Star Atlas, with very similar maps,
just not quite as detailed. For meteor observing, star maps covering many
constellations are easier to use.
Our NAMN website has a set of handy star charts to print off. These have sky
coordinates marked on them - both in RA and Dec, and also in the degree
system used by the IMO. Stars that you can use to judge the brightness of
the meteors you see, are circled on these maps, with their magnitude marked.
Print them off from:
http://web.infoavedot net/~meteorobs/charts.html.
What showers are visible? There are a number of sources that list the meteor
showers visible during the year.
Our NAMN website gives a summary table of the year's showers, at:
http://web.infoavedot net/~meteorobs/2001targets.html. Each month, we provide
details in NAMN Notes as to what showers can be observed, and details on
them, such as where they seem to come from in the sky, their velocity, and
how many meteors you would expect to see.
The IMO website, http://www.imodot net, is the source of this list, and on
their website, further details are given on some of the showers on this 'IMO
Working List' . We highly recommend printing off a copy of their '2001
Meteor Shower Calendar' . The 2001 calendar prints to 31 pages. Keep it in a
binder - it's a great reference for activity during the year. Many maps are
given for specific meteor shower radiants.
Another good source of information on meteor showers is Gary Kronk's 'Comets
and Meteor Showers' website at http://comets.amsmeteors.org. This
provides information month-by-month on showers visible over the years by
visual, telescopic, photographic, and radio means. Some showers have been
seen by one means - but not by others. It is fascinating reading.
For those interested in recording data on the meteors you see, what do you
need to record?
A good source in this regard is our NAMN Observing Guide at
http://web.infoavedot net/~meteorobs/guide.html.
Other sources of information include the IMO website at http://www.imodot net,
and the IMO Handbook for Visual Meteor Observers. This is currently being
revised for reprinting, but they may have older copies still available.
The book 'Meteors' by Neil Bone is a good reference book, and available
through Sky Publishing at http://www.skypub.com.
What about specific questions that you may have about meteors, fireballs,
and meteor observing?
The IMO website at http://www.imodot net has a great list of meteor links.
These tools should help get you started! If you have questions, drop a note
to the NAMN Coordinator at MeteorObs@charlestondot net.
4. Upcoming Meetings...
August 6-10, 2001 - Sweden:
The Meteoroids 2001 conference will be held at the Swedish Institute of
Space Physics in Kiruna, Sweden. Topics covered will include historical
observations and perspectives on meteoroids; dynamics, sources and
spatial distribution; detection and characteristics of meteoroids from
interstellar space; the meteoroid interaction process in the atmosphere;
hypervelocity impact effects on spacecraft; Leonid meteor storms;
optical observations of meteors; and meteor radar work. For
information, contact Asta Pellinen-Wannberg at
asta.pellinen-wannberg@irf.se and check out the website at
http://www.irf.se/Meteoroids2001.
September 20-23, 2001 - Slovenia:
IMC 2001, the annual convention of the International Meteor
Organization, will be held northwest of Ljubljana, in a mountain resort
in the Julian Alps. This is a worldwide meeting for all amateur meteor
observers - not just for professionals. Slovenia is on the Adriatic
Sea, just east of the top of Italy, and on the southern border of
Austria. North American observers are particularly encouraged to
consider taking a vacation to Europe this year to attend! It is a
wonderful opportunity to get to meet observers from around the globe -
and to see some of the most scenic parts of Europe at the same time!
For more information, check out the IMO website at http://www.imodot net.
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 February...
February 2001 NAMN Notes co-written
by Mark Davis and Cathy Hall
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