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Welcome to the Final Event of Astronomy On-Line! We would like all groups to participate in this, and we hope that it will be possible also for your group to find the necessary time to do so!
This event involves astronomical observations, but if your group is unlucky with the weather, you can still participate.
Determine your geographical latitude!
The Astronomy On-line groups are located in 39 countries all over the world. We would like you to determine your geographical latitude and to report it to us, so that we can find out how the groups are distributed from south to north. This is actually quite easy by means of simple astronomical observations.
We ask you to do so during the next 3 days and to deliver the result not later than Thursday, November 21 at 18 hrs UT.
We suggest that you use one of four different methods, but we would prefer that you try to use the first or the second one, if at all possible.
By determining the altitude of the Polar Star over the northern horizon, you will be able to determine at the same time your geographical latitude.
A very detailed explanation is available. Please read it carefully and use one of the sighting methods described in that text to make this observation during one of the coming evenings.
Remember, that the altitude of the Polar Star is equal to your geographical latitude!
If the weather is partially clouded, or if you live south of the terrestrial equator, you will not be able to see the Polar Star. In that case, we propose that you observe the altitude of the Sun at local noon. That is when the sun reaches the highest point in the sky.
Detailed instructions are available in connection with the Erathostenes Collaborative Project. There is also much information in connection with the determination of Local Noon (within the Lunar Eclipse Project) By using a simple gnomon, this should be a quite simple observation.
Once you have measured the altitude of the Sun, it is easy to determine your geographical latitude by means of the following formula (all angles expressed in degrees):
Your geographical latitude = 90 + solar declination - solar altitude.
If you live far south and see the Sun towards the North, you should add 90 deg to the measured altitude in the following calculation.
The solar declination is as follows during the next days:
November 0 h UT 18 -19 deg 14 min 19 -19 deg 28 min 20 -19 deg 42 min 21 -19 deg 55 min 22 -20 deg 08 min 23 -20 deg 21 min
For instance, if you measure a solar altitude of 60 degrees on November 19, then your geographical latitude is 10.5 degrees North (90 + (-19.5) - 60 = +10.5).
If the weather is extremely bad and no astronomical observations are possible at all in your place, you may search on the Web to find the geographical latitude of the town you live in (Hint: try one of the Search Engines). This may take a little time, but if the weather is bad anyhow that should be no problem for you!
If everything else fails, you may have a look at the local map with geographical latitudes and read from it your geographical latitude.
Of course, this is only the final and most desperate solution to this problem!
Once you have determined your geographical latitude, we ask you kindly to send it by email to the following address: Final Event Committee. Please be sure to indicate the designation of your group, the town and country in which you are located, your geographical latitude as determined above, and the method (1 - 4, as above) by which you determined it.
Once we have received all results we will make a combined Table which will be available on the last day of the Hot Phase, Friday, November 22, 1996. We will use this Table in different ways which will remain a surprise until that day.
Good luck with your observations!
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