From "DREAM"
by Boris Levinson
I, a child
Try to reach the stars. . .
Sirius is so near.
I run to the nearest hill
My reach is always too short
Wait till I am a grown man!
Now, I am old and bent with years
No more running to the hill and mountain top --
Yet, a warm, steady, life-giving glow
Reaches me from Sirius. . . the unattainable.
I collect
White iridescent and evanescent starbeams
For my trip home to
Sirius the dog star.
We have all heard or used the expression "The Dog Days of Summer." Many of us likely assume that the phrase originated from areas where the climate was so hot and oppressive that dogs would lie about in a heat-induced stupor.
The actual origin is much more fascinating and is just another cosmological morsel to savor.
**All stars shine but none do it like Sirius, the brightest star in the night sky. Aptly named, Sirius comes from the Greek word Seirius, meaning, "searing" or "scorching." Blazing at a visual magnitude of -1.42, it is twice as bright as any other star in our sky.
Sirius resides in the constellation Canis Major, the Big Dog, and is commonly called the Dog Star. In ancient Greek times the dawn rising of Sirius marked the hottest part of summer. This is the origin of the phrase "dog days of summer."
Because of Earth's 26,000 year precession cycle, in which the planet's axis slowly wobbles due to the gravitational attraction of the Sun and Moon on the Earth's equatorial bulge, Sirius no longer marks the hottest part of summer, rising later in the year. Precession gradually changes the location of stars on the celestial sphere.
Sirius is best seen at a favorable time during the winter months for northern hemisphere observers. To find the Dog Star, use the constellation of Orion as a guide. Follow the three belt stars -- obvious targets even for casual skywatchers -- 20 degrees southeast to the brightest star in the sky. Your fist at arm's length covers about 10 degrees of sky.
Sirius, the red giant star Betelgeuse, and Procyon in Canis Minor form a popular asterism known as the Winter Triangle.
Intrinsically, Sirius is 23 times more luminous and about twice the mass and diameter of the Sun. Of course it's farther away from Earth than the Sun. But not too far, cosmically speaking. At a mere 8.5 light-years distant, Sirius seems so bright in part because it is fifth closest star to the Sun.
The actual origin is much more fascinating and is just another cosmological morsel to savor.
**All stars shine but none do it like Sirius, the brightest star in the night sky. Aptly named, Sirius comes from the Greek word Seirius, meaning, "searing" or "scorching." Blazing at a visual magnitude of -1.42, it is twice as bright as any other star in our sky.
Sirius resides in the constellation Canis Major, the Big Dog, and is commonly called the Dog Star. In ancient Greek times the dawn rising of Sirius marked the hottest part of summer. This is the origin of the phrase "dog days of summer."
Because of Earth's 26,000 year precession cycle, in which the planet's axis slowly wobbles due to the gravitational attraction of the Sun and Moon on the Earth's equatorial bulge, Sirius no longer marks the hottest part of summer, rising later in the year. Precession gradually changes the location of stars on the celestial sphere.
Sirius is best seen at a favorable time during the winter months for northern hemisphere observers. To find the Dog Star, use the constellation of Orion as a guide. Follow the three belt stars -- obvious targets even for casual skywatchers -- 20 degrees southeast to the brightest star in the sky. Your fist at arm's length covers about 10 degrees of sky.
Sirius, the red giant star Betelgeuse, and Procyon in Canis Minor form a popular asterism known as the Winter Triangle.
Intrinsically, Sirius is 23 times more luminous and about twice the mass and diameter of the Sun. Of course it's farther away from Earth than the Sun. But not too far, cosmically speaking. At a mere 8.5 light-years distant, Sirius seems so bright in part because it is fifth closest star to the Sun.
In 1844, German astronomer Friedrich Bessel observed that Sirius had a wobble, as if being tugged by a companion. While testing his new 18.5-inch lens in 1862 (the largest refracting telescope in the world at that time), Alvan Clark solved this mystery by discovering that Sirius was not one star but two; the first compact stellar remnant had been discovered, and it would prove to be a pioneer of what would be later referred to as a whole class of white dwarf stars.
The companion, dubbed Sirius B, has the mass of the Sun in a package as small as the Earth, having collapsed after depleting its hydrogen. A single cubic inch of matter from this companion star would weigh 2.25 tons on Earth. At magnitude 8.5, it is 1/400th as luminous as the Sun. The brighter and larger companion is now known as Sirius A.**
**article taken from: "The 10 Brightest Stars"
By Pedro Braganca
Special to SPACE.com
posted: 07:00 am ET
15 July 2003
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