After being rendered invisible due to its proximity to the sun for a few months each year, the star would rise out of the dawn twilight , an event known as the star's "heliacal rising. Year after year, this would herald the annual flooding of the Nile Valley, so, quite naturally, the Egyptians concluded that this star brought about the life-giving flood of their river. People then opened the gates of canals, allowing the waters to refertilize their fields with silt.
Around B. The chief reason for the great brilliance of Sirius is its relative closeness to us. At only 8. In fact, based on calculations derived from the European Space Agency's Hipparcos satellite launched in , Sirius is on a course taking it closer to our solar system over the next 60, years.
So, this star will appear to become a bit brighter over the next 60 millennia, before receding and slowly getting fainter. And yet, it will still hold on to the title of "most brilliant" among the naked-eye stars for at least another , years. Shining at magnitude As previously noted, Sirius' closeness is the chief reason it appears so bright. If we could move the star out to a distance of 10 parsecs — Compared to our sun, it shines with about 25 times the luminosity , is nearly twice as wide as and is more than twice as massive.
Sirius is not a single star, but a double star, also known as a binary star system. Although it may look like one star to the naked eye, Sirius consists of two stars that are very close together, known as Sirius A and Sirius B. Between and , the noted German astronomer, mathematician and physicist Friedrich W. Bessel discovered that Sirius did not travel on a straight path through space, but rather it displayed wavy irregularities. Bessel concluded that an invisible companion revolved about Sirius, taking about 50 years to make one revolution.
In , the famous telescope maker Alvan Clark, while testing a new Canis Major contains one Messier object, M This is an open star cluster containing about stars. It is 26 light years in diameter and is located 2, light years from Earth. A few other notable deep-sky objects can also be found here. These dim objects can only be seen with a large telescope. The Canis Major Dwarf Galaxy, also known as the Canis Major Overdensity, is an irregular galaxy that is thought to be the closest neighboring galaxy to our solar system.
NGC and IC are a pair of interacting spiral galaxies that are in the process of colliding with each other. They will eventually merge to form a larger galaxy. To search this site, type your search word s in the box below and click the search button:. All rights reserved. Content from this Website may not be used in any form without written permission from the site owner.
Sea and Sky receives commissions for purchases made through links on this site. On Sept. The very next morning, shining at magnitude This lovely event will be best seen in binoculars or a wide-field telescope. Sunrise or late in the morning twilight is usually the best time to study Venus in telescopes. Right now, Canis Major can be seen emerging from the southeastern horizon just as dawn is beginning to break.
But it's not the largest. University of Minnesota professor Roberta Humphreys recently calculated that it may be more than 2, times the size of the sun.
Light would take more than 8. If we could shrink the sun down to the size of a baseball, VY Canis Majoris would be a globe measuring feet But using the word "globe" to describe this star is actually a bit misleading; a globe suggests a solid object, but there is nothing solid about VY Canis Majoris. In fact, the star is a thousand times less dense than Earth's atmosphere at sea level.
VY Canis Majoris is an M-type star, a cool red star with a temperature of about 5, degrees Fahrenheit 3, degrees Celsius. And it is enveloped by a huge nebula sporting a complex structure with filaments and arcs caused by past eruptions. The star is the source of considerable controversy, since the estimates of its size and luminosity fall outside the bounds of current stellar theory.
And as for its future, VY Canis Majoris is forecast to become a "hypernova" sometime within the next , years, producing a burst of energy that would be substantially higher than the typical supernova star explosions. Hypernovas are believed to be the origin of long-duration gamma-ray bursts. VY Canis Majoris might even end up as a large black hole.
The Brightest Star: In , UCLA astronomers using NASA's Hubble Space Telescope identified what may be the most luminous star known — a celestial mammoth 25, light-years away that releases up to 10 million times the energy of the sun and is big enough to fill the diameter of Earth's orbit.
Unfortunately, this amazing star is not visible to skywatchers here on Earth.
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