User`s guide

Object Databases 81
Pluto, too dim to see. Once in a long while,
they come close to Earth and the Sun,
picking up speed and getting brighter.
Starry Night includes about 150 comets,
including some great comets of yesteryear
such as Halley and Hale-Bopp. Comet data
needs to be updated regularly, so that any
bright new comets are added to Starry
Night’s database. See “Database Updates
”
on page 85 for information on updating
comet data.
Planets/Moons: The Sun, the nine major
planets that orbit the Sun, and all of the
moons of these planets. In the past few
years, many new small moons have been
discovered around the outer planets. Starry
Night includes all of the moons that were
known at the time of release. If any new
moons are discovered in the future, data
for these moons will be available on our
website. Choose
View->Check For Program Updates to
see if any new data is available.
Space Missions: Interplanetary spacecraft
and probes. Follow the path of Voyager,
Cassini, Pioneer and other space missions.
Databases 2 (Stars)
This includes not only stars, but all objects
that are outside of our solar system, but
still inside our galaxy, the Milky Way.
Milky Way: The band of our Milky Way,
which stretches across the night sky. The
misty band of illumination that we see is
actually the combined light of millions of
stars. It is possible to adjust the brightness
of the Milky Way.
Pulsars: Starry Night Pro and Pro Plus
have a catalogue of more than 700 pulsars.
Pulsars are neutron stars, former
supergiants that have been compressed
into spheres with diameters of only a few
tens of kilometres. Created by Ulf Teras.
Stars: A star is any body which burns or
once burned hydrogen fuel. The energy
and light produced in stars comes from the
fusion of hydrogen atoms. As stars grow
older, they use up their supply of hydrogen
and have to find other sources of energy.
When they reach this point, they become
either red giants or supergiants, depending
on their size. As they continue to use up
energy, stars eventually become either
white dwarfs or, in the case of very
massive stars, neutron stars or black holes.
The star database in Starry Night is
actually a compilation of databases: Starry
Night Enthusiast uses the Hipparcos
catalogue, and the Tycho-2 catalogue, and
Starry Night Pro and Pro Plus also include
the USNO-A2 catalogue.
The Hipparcos and Tycho-2 catalogues
come from a European Space Agency
project to determine the distance to our
nearest stars. The Hipparcos catalogue has
about 100 000 stars and the Tycho-2
catalogue has about two million. Find out
more about these catalogues on their
official web page: http://a
stro.estec.esa.nl/
SA-general/Projects/Hipparcos/
hipparcos.html
Starry Night Pro and Pro Plus use the
USNO-A2 star database for dim stars not
included in the Hipparcos or Tycho
catalogues. About 75 million stars as dim
as 15th magnitude can be accessed. These