Lew & Karen's Home Page

What is meteorobs?

Email Access to meteorobs

History of meteorobs

Search meteorobs Archive...

Browse Archive by Month...

Frequently Asked Questions

Meteor-Related Links

How to View Meteor Showers

METEOR STORMS (Leonids etc.)

Going Deeper: Telescopic Meteors

MeteorObs -
an Internet forum for meteor observers of all levels

Going Deeper: Telescopic Meteor Observing

+ What are Telescopic Meteors? + Telescopic Means Plotting! + Telescopic Meteor Plotting Tips + Getting Started in "TM" + How To Learn More about "TM" + TM Challenge of the Month

What are Telescopic Meteors?

Telescopic Meteor Observing is just what the name implies: observing (and recording) meteors with a telescope or binoculars! This type of observing is very demanding on the observing (it requires looking through an eyepiece steadily at one field for a full half hour), but also offers some wonderful and unique opportunities to contribute to the science of meteors.

Note that the best way to introduce yourself to telescopic meteor observing is by first learning as much as possible about unaided-eye meteor observing, and in particular meteor plotting! If you would like to find out how YOU can see a "Shooting Star Show" in your area, please take the time to review in detail our pages on How to View Meteor Showers.

If you are interested in subscribing to the 'meteorobs' mailing list, you may use the MeteorObs Subscription Web form now! Otherwise, you may post a (moderated) message to the list even if you are not a subscriber.


Telescopic Meteors Means Plotting Meteors!

If you're determined to try telescopic observing (which I encourage all meteor observers to do at some point!), then keep in mind that the best way to make use of the telescope is by plotting what you see... Counting meteors through a telescope can be fun: However, please be aware that there are no currently accepted methods for calibrating, analyzing or researching meteor rates as seen through an eyepiece. Measuring fluxes of faint meteors would be possible only with many more active observers and far more historical data.

Plotting is the raison d'etre for telescopic observing. And in fact, shower association at the eyepiece can be very difficult indeed! In any case, it's actually prefered that you don't make shower associations immediately at the eyepiece. Instead, simply plot what you see relative to the star background, as accurately as possible. The plotted trails allow objective criteria to be applied in assessing shower assignment. The criteria can also be modified, something that's not possible with an on-the-spot decision.


Telescopic Meteor Plotting Tips

One Tip: Don't observe telescopically by pointing your instrument directly at a shower radiant. You will see far more if instead you choose a field 15 to 25 degrees away from the radiant point in the sky. Some visual observers have their center of vision at major-shower radiants. That's feasible because the unaided eye has a much wider field of view than telescopes.

For those interested in trying "TM" (Telescopic Meteor plotting), be aware that you'll see relatively fewer meteors than with unaided-eye observing: Telescopic rates tend to be about 50% to 80% of visual rates for experienced observers. This goes down in major showers which have relatively few faint meteors, such as the Perseids.

Both telescopes and binoculars can be used for TM. But no matter what instrument you choose to observe with, be sure it is one you can use in a very comfortable position, and one you do not have to hold in your hands throughout the time you are watching - in other words, your instrument must be mounted! This is PARAMOUNT.


Getting Started in Telescopic Meteors

Malcolm Currie, Telescopic Meteor Commission Chairman of the International Meteor Organization, suggests the following route for getting started in TM:

a) Begin with visual (unaided-eye) counts: learning the constellations and the basics of meteor observing, including estimating your Limiting Magnitude. You can read up on these basics via the Web.

b) After becoming proficient at (a), try visual plotting when there is no major shower active. This means obtaining a set of standard gnomonic star charts (charts that show Great Circles as straight lines). Instructions on plotting can be obtained at the American Meteor Society's Web site, in Norman McLeod's Meteor Plotting. Proper gnomonic charts can be obtained from the North American Meteor Network and from the International Meteor Organization.

c) Once you are comfortable with unaided-eye plotting, you are ready to try telescopic meteors. Telescopic observing is demanding, for it requires good concentration and patience to start. Rates start slowly but increase with experience. (It took Malcolm Currie, IMO Telescopic Commissioner, several false starts to get going. Now he has an observing set up which allows him to observe comfortably for many hours.)


How To Learn Much More about Telescopic Meteors

The most definitive current TM reference is Malcolm Currie's guide: http://www.jach.hawaii.edu/~mjc/imo/tele/telescopic.html
Though there are still non-functioning links on these pages, and some are in an unfinished state, they are "required browsing" for anyone who is seriously interested in Telescopic Observing. See in particular the Introduction and pages on "Observation Techniques" and "Reports".

The NAMN observing Guide also has a chapter on telescopic meteors:


Telescopic Challenge of the Month: "June Lyrids and Xi Draconids!"

These two showers, both active throughout the middle of June, have both proved elusive for visual observers in recent years. The June Lyrids (JLYs), a long known shower, and the Xi Draconids, a recently "discovered" shower that may or may not be related to the JLYs, both represent an excellent opportunity for Telescopic observers to contribute to our knowledge of annual streams!

According to IMO Telescopic Commissioner Malcolm Currie, "Telescopic (and video) techniques will let us locate the radiant if these showers actually occur, and thus complement visual observing which can provide a ZHR/flux curve."

Malcolm goes on to note, "The 'usual rules' apply: alternate between fields every half hour. Concentrate on careful plotting. For many observers, it will be a short night affected by twilight. If given a choice of instruments to use under twilight skies, choose the one with the smaller exit pupil - this will make for more comfortable viewing, as the eye can accept the smaller beam and the contrast improves."

Below are downloadable copies of the best trio of charts to use for researching BOTH of these elusive showers. NOTE that observers who have trouble locating Chart 68 may choose instead to use nearby Chart 67. Chart 68 has few unaided-eye stars, whereas Chart 67 contains the bright asterism of Nu, Phi, and Chi Herculis, and so may be easier to find.

Still, Chart 68 is preferred as it lies closer to the radiants of these two relatively fast-moving showers.

These "A" charts are scaled for small (30-50mm) binoculars:
Preferred Trio: TA068 TA070 TA086
Alternate Trio: TA067 TA070 TA086

For those with large-aperture binoculars or small non-inverting telescopes (binoculars or scopes in the 60-80mm aperture range), these deeper-magnitude and narrower-field "B" versions of the charts above will be more useful!
Preferred Trio: TB068 TB070 TB086
Alternate Trio: TB067 TB070 TB086

Finally, if you have a rich field telescope (of over 80mm aperture, but with at least 3 degrees true field at low power), use the following "D" charts. These show stars all the way down to magnitude 12.5, and are laterally inverted so that they may be used with a (90 degree) star diagonal.
Preferred Trio: TD068 TD070 TD086
Alternate Trio: TD067 TD070 TD086

Clear skies!
Lew Gramer <dedalus@alum.mit.edu>
Malcolm Currie <mjc@star.rl.ac.uk>