STAR 5
Size and Mass
All stars we see as little dots. Even with the strongest telescope
this doesn’t change.
On pictures Brighter stars look larger than weaker stars, butt this
size doesn’t say anything about the real size.
To measure the size of a star the following information is
combined:
- Brightness (amount of radiated light, determined by the distance
and the apparent brightness)
- surface temperature (determined by spectral type))
This way we figured out that some stars are smaller than our own
sun while others are thousand times bigger. Compare this with a
camp fire wich gives more light than a fitter flame.The camp fire
has a lower temperature but a bigger size.
Two stars wich, seen from the earth, are almost on the same
position in the sky are called double stars.
William Herschel made a catalogue of 800 of those double stars
between 1782 and 1821.
His son John Herschel discovered more than 10.000 optical double
stars.
These are stars wich are situated in the same direction but on a
different distance. Lots of double stars are really double stars
wich are orbiting around each other.These are called fysical double
stars.
If atronomersw really can see these stars orbitting around each
other they are called visual double stars. From the orbit of these
double stars astronomers can calculate the mass of stars.
Big numbers are not written out compleet, but in indices.
As an example 100 (=10 x 10) is written as 102 and 1.000.000
(=10 x 10 x 10 x 10 x 10 x 10) as 106.
F.i. 1.3 x 102 would be 1.3 x 10 x 10 = 130.
Our sun has a mass of 1,989 x 1030 kg. And a diameter of 13.920
x 108 meter.
Our earth has a mass of 5.974 x 1024 kg and a diameter of 12756 x
103 meter.
Our moon has a mass of 7.349 x 1022 kg and a diameter of 3476 x 103
meter.
Scale of star sizes.
And now what it is all about:
Solve the puzzle and find the cache at the given location:
Write down the code you will find inside the cache
You will find GZ at:
S 34 43. ( 4,23 X 102)
E 150 48. ( 0,873 X 103)
.
http://www.stargazing.net/astropc/index.html
http://www.worldwidetelescope.org/
You can check your answers for this puzzle on Geochecker.com.
(With many, many thanks to Ozzeger, Blerick, Netherlands!) HONOURS FOR FTF GO TO TEAM CASHO!