<s>
Planetarium	B-Application
software	I-Application
is	O
application	B-Application
software	I-Application
that	O
allows	O
a	O
user	O
to	O
simulate	O
the	O
celestial	O
sphere	O
at	O
any	O
time	O
of	O
day	O
,	O
especially	O
at	O
night	B-Application
,	O
on	O
a	O
computer	O
.	O
</s>
<s>
Such	O
applications	O
can	O
be	O
as	O
rudimentary	O
as	O
displaying	O
a	O
star	O
chart	O
or	O
sky	B-Application
map	I-Application
for	O
a	O
specific	O
time	O
and	O
location	O
,	O
or	O
as	O
complex	O
as	O
rendering	O
photorealistic	O
views	O
of	O
the	O
sky	O
.	O
</s>
<s>
While	O
some	O
planetarium	B-Application
software	I-Application
is	O
meant	O
to	O
be	O
used	O
exclusively	O
on	O
a	O
personal	O
computer	O
,	O
some	O
applications	O
can	O
be	O
used	O
to	O
interface	O
with	O
and	O
control	B-Application
telescopes	I-Application
or	O
planetarium	O
projectors	O
.	O
</s>
