Sirius lies almost in line with the three stars that form the Belt
of Orion. We shall not have the slightest difficulty in recognizing
it, owing to its surpassing brilliancy as well as to the fact that it
follows so closely upon the heels of Orion.
Sirius is the Greek for "scorching" or "sparkling," and the ancients
attributed the scorching heat of summer to the fact that Sirius
then rose with the sun. The torrid days of midsummer they called
the "dog-days" for this reason, and we have retained the expression
to the present time. Since Sirius was always associated with the
discomforts of the torrid season, it did not have an enviable
reputation among the Greeks. We find in Pope's translation of the
_Iliad_ this reference to Sirius:
"Terrific glory! for his burning breath
Taints the red air with fever, plagues, and death."
In Egypt, however, many temples were dedicated to the worship of
Sirius, for the reason that some five thousand years ago it rose
with the sun at the time of the summer solstice, which marks the
beginning of summer, and heralded the approaching inundation of the
Nile, which was an occasion for great rejoicing among the Egyptians.
It was, therefore, called the Nile Star and regarded by them with the
greatest reverence.
Sirius is an intensely white hydrogen star; but owing to its great
brilliancy and to the fact that it does not attain a great height
above the horizon in our latitudes, its rays are greatly refracted
or broken up by the atmosphere, which is most dense near the horizon,
and as a result, it twinkles or scintillates more noticeably than
other stars and flashes the spectrum colors--chiefly red and
green--like a true "diamond in the sky"--a magnificent object in the
telescope.
Sirius is one of our nearest neighbors among the stars. Only two
stars are known to be nearer to the solar system. Yet its light takes
about eight and a half years to flash with lightning speed across the
great intervening chasm. It is attended also by a very faint star
that is so lost in the rays of its brilliant companion that it can
only be found with the aid of a powerful telescope. The two stars
are separated by a distance of 1,800,000,000 miles; that is they are
about as far apart as Neptune and the sun. They swing slowly and
majestically about a common center, called their center of gravity,
in a period of about forty-nine years. So faint is the companion of
Sirius that it is estimated that twenty thousand such stars would be
needed to give forth as much light as Sirius. The two stars together,
Sirius and its companion, give forth twenty-six times as much light
as our own sun. They weigh only about three times as much, however.
The companion of Sirius, in spite of its extreme faintness, weighs
fully half as much as the brilliant star.
[Illustration: MARCH--CANIS MAJOR]
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account