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Sirius

Sirius, also known as the Dog Star, is the brightest star in Earth's night sky. It lies in the constellation Canis Major and is a prominent feature of the winter skies in the Northern Hemisphere.

It is a binary star system consisting of Sirius A, a hot white main-sequence star (spectral type

Sirius B orbits Sirius A with a period of roughly 50 years, at an average separation of

Etymology and cultural significance: The name Sirius derives from the Greek Seirios, meaning scorching or glowing.

Observational and scientific notes: Sirius has contributed to understanding stellar evolution, binary star dynamics, and white

A1V),
and
a
faint
companion,
Sirius
B,
a
white
dwarf.
Sirius
A
shines
with
about
25
times
the
Sun’s
luminosity
and
has
a
surface
temperature
around
9,900
kelvin,
giving
it
a
blue-white
hue.
The
system
is
located
about
8.6
light-years
from
Earth,
making
it
one
of
the
nearest
naked-eye
stars.
The
apparent
magnitude
of
Sirius
can
reach
about
−1.46,
making
it
easily
visible
even
in
light-polluted
skies.
There
are
no
confirmed
exoplanets
in
the
Sirius
system.
about
20
astronomical
units.
The
mass
of
Sirius
B
is
near
one
solar
mass,
while
Sirius
A
is
more
massive,
around
2
solar
masses.
Historically,
the
heliacal
rising
of
Sirius
around
the
onset
of
summer
was
associated
with
the
hot
season
in
various
cultures;
in
ancient
Egypt
it
signaled
the
Nile
flood
cycle
and
the
new
year.
The
phrase
Dog
Days
of
Summer
originates
from
this
star’s
appearance
in
the
sky.
dwarfs.