(Section Not Complete)
HR diagram for the globular cluster M5 in the constellation Serpens.
HR diagram for open clusters h and chi Persei.
Properties of Stars
The Harvard Spectral Sequence
||Ionized He and metals;
|28,000 - 60,000
||Neutral He, ionized metals,
||10,000 - 28,000
||Balmer H dominant, singly-ionized
||7500 - 10,000
||H weaker, neutral and
||6000 - 7500
||Singly ionized Ca, H weaker,
||5000 - 6000
||Neutral Metals, molecular
begin to appear
|3500 - 5000
||Ti oxide molecular lines; neutral
DATABASE of GENEVA STELLAR EVOLUTION MODELS:
"An extensive and homogenous database of stellar evolution models for masses
between 0.8 and 120 solar
masses at different metallicities is available. In general the models include
evolutionary phases from the
main sequence up to the end of carbon burning for massive stars. Horizontal
branch and early asymptotic
giant branch models are also provided. The metallicities covered are Z=0.001,
0.004, 0.008, 0.020
(=Z_solar), and Z=0.04.
In addition to the evolutionary grids we also provide Fortran codes for the
calculation of isochrones and
stellar population burst models.
Recent models now cover also pre-main sequence phases. Predictions regarding
the spectral evolution of
massive stars can be obtained from the so-called "combined stellar structure
and atmosphere models"
A (somewhat flaky) DOS program (StarClock)
written in Pascal that implements graphic HR
diagram evolution based on the above tables can be found at
Go to the Dome of the Sky. Select "Enter the Dome"
and then select sky charts for a northern latitude (say New Orleans, at 30 degrees N). Select the sky
chart for December 20 and locate the characteristic shape of the constellation Orion on the celestial
equator to the left of center. Click on the brighter stars in Orion to display information about them
(use the status bar at the bottom of the browser to help
ensure that you are over the star when you click; for example, it should display "Betelgeuse" when the
cursor is over that star). Use the
HTML Tablemaker to make a table of the following information (if given) for the brightest
stars in Orion: Name, Spectral Class, Color Index, Distance, Visual Magnitude. Put this table into your
astronomy homepage if you are constructing one (see the instructions on the Tablemaker interface).