(meteorobs) Re: Perseids Live ZHR Profile

[Robert Lunsford]

Arlene and All,

Wayne has presented some fine pointers in order to produce a scientifically 
useful meteor report. Personally I would not expect anyone to be able to 
provide all this information on their first night out observing. I would 
suggest providing what information you can and then work on providing the 
remainder as you become more proficient in recording.

I feel the most important contribution you can provide is the number of 
Perseids verses non-Perseids per hour. The Perseids will be easy to 
distinguish as they will all come from the northeastern sky and shoot in all 
directions. There will be fast Perseids and slow Perseids. Fast Perseids 
will appear far from the radiant and high in the sky. Slow Perseids will 
appear near the radiant or near the horizon. As you see numerous Perseids 
you will also notice an occasional meteor coming from a different direction. 
These are either sporadic meteors or those belonging to other showers active 
this time of year. A great majority of the activity you see on the next four 
night will be Perseids.

During slow periods (yes there will be periods as long as five minutes when 
you see nothing) I would suggest becoming familiar with the magnitude 
system. At midnight (summer time) Jupiter lies low in the southwest. Jupiter 
shines at magnitude -2. Located just west of the zenith is the zero 
magnitude blue-white star Vega. First magnitude Deneb lies almost exactly 
overhead at this hour. The north star and the brighter stars of the Big 
Dipper are fine examples of second magnitude stars. The "W" of Cassiopeia, 
rising in the northeast has  two second and four third magnitude stars. The 
dim constellation of Delphinus, located due east of the bright first 
magnitude star Altair (located half-way up in the south) is made up entirely 
of fourth magnitude stars. It's difficult to pick out fifth magnitude stars 
as there are so many of them! They as best described as the dimmest stars 
you can easily see from a rural location. Sixth magnitude stars are the 
stars you can barely see.

As you gain experience you will be able to apply these magnitudes to the 
meteors you record, which is important for scientific analysis. The main 
thing though is to enjoy the show while providing enough information to give 
us an idea of what you witnessed.

Clear Skies!

Bob Lunsford


----- Original Message ----- 
From: <meteors at eclipse.net>
To: "Global Meteor Observing Forum" <meteorobs at meteorobs.org>
Sent: Friday, August 10, 2007 8:49 AM
Subject: Re: (meteorobs) Perseids Live ZHR Profile


> Arlene,
> To record scientifically useful data you must be able to enter:
>
> 1:
> The Latitude, Longitude and Height above sea level at your observing
> location.
> 2:
> The location of the radiants of any meteor showers you are observing, in
> Right Ascention and Declination
>
> 3:
> The RA and Dec of your field of view (where you are looking)
>
> 4:
> The exact hours (minutes/60 minutes per hour) that you were watching the 
> sky.
>
> 5:
> Whether any clouds or trees or buildings obstructed your field of view.
>
> 6:
> The beginning and end time of your observations.
>
> 7:
> The limiting magnitude of your sky (what is the magnitude of the faintest
> stars you can see). The IMO uses a "counting the stars in a polygon"
> method which is easy to learn with some practice.
>
> 8:
> The number of meteors from each shower you observed for each time 
> interval.
>
> 9:
> The Magnitude (brightness) of the meteors you see.
>
> I would suggest as a starting point, you go to
>
> http://www.namnmeteors.org/
>
> And look at the observing forms.
> Download the NAMN observing guide.
> See if you can fill out the form,
> http://www.namnmeteors.org/namn_form.html
>
> If you have questions, ask me or Mark at the NAMN and we'll help you.
>
> It's intended as an introduction to the science of recording your
> observations.
>
> A printable IMO report form is also available, but my advice is to start
> with the NAMN form, until you have all the bugs worked out.
>
> It takes a bit of practice to be able to fill it all out accurately.
>
> Wayne