The constellation Orion is one of the most beautiful in the night sky. It has been familiar to many since childhood: it is difficult to ignore it, since the most noticeable stars and celestial objects in the constellation Orion are visible from the Earth with the naked eye. Among them are luminaries that are superior to the Sun in a number of parameters, and the beautiful Large Nebula M42. Two bright stars in the constellation Orion, Rigel and Betelgeuse, are very easy to find in the sky. They facilitate the detection of the remaining elements of the constellation.
Description
Orion is an ancient mythical character, a skilled hunter, ally and beloved of Artemis. Legends and myths about the constellation Orion tell that it appeared in heaven at the behest of the inconsolable goddess who killed the hunter as a result of the cunning of her jealous brother Apollo. Artemis vowed to remember her lover forever and placed him in heaven.
In the arrangement of elements, it is very easy to guess the silhouette of a hunter. He froze in the sky with a raised club, a sword on his belt and a shield in his hand. Details of the constellation are known asterisms. A sheaf forms a characteristic figure. The Orion belt is formed by three clearly visible stars located on one straight line. Asterism of Orion Sword is located a little lower, including two stars and between them a blurry speck of the M42 nebula. The belt at the southeastern end of the line points to Sirius, and the northwest to Aldebaran.
Each bright star in the constellation of Orion is impressive. The constellations surrounding it lose in beauty precisely because of the absence of such a large number of elements impressive in their luminosity.
Palm
Against the backdrop of all this splendor, a couple of giants stand out. The historical name of two bright stars in the constellation Orion - Rigel and Betelgeuse. Their scientific designation is Beta and Alpha Orion, respectively. Both giants, as already mentioned, are perfectly visible from Earth. We can say that they compete for the title of the first star in this heavenly figure. Betelgeuse is designated as Alpha, but Rigel is somewhat brighter.
The name of the two bright stars in the constellation Orion is of Arab origin. The crossbar in translation means "leg", and Betelgeuse means "armpit". The names of the stars, thus, give an approximate understanding of where the luminaries are located. Alpha Orion is located on the hunter's right armpit, and Beta is on his leg.
Red supergiant
Betelgeuse in many ways can be considered the most significant luminary in Orion. This is a red supergiant related to semi-regular variable stars: its brightness varies from 0.2 to 1.2 magnitude. Moreover, a lower luminosity limit exceeds the level of this parameter in the Sun by eighty thousand times. The distance between the star and the Earth is estimated at 570 light years on average (the exact value of the parameter is unknown).
The scale of Betelgeuse can be realized by comparing them with the sizes of the orbits of the planets of the solar system. The minimum size of a star, if placed in the place of our luminary, would cover the entire space up to the orbit of Mars. Maximum - would correspond to the orbit of Jupiter. The Betelgeuse mass is 13-17 times more solar.
Learning problems
Alpha Orion is 300 million times the size of the Sun. Its exact diameter is difficult to measure, since its brightness slowly decreases with distance from the center of the star. It is generally accepted that if the distance to Betelgeuse is taken for 650 light years, then its diameter varies from 500 to 800 corresponding parameters of our star.
Betelgeuse is the first star after the Sun, for which they were able to obtain a disk image using a space telescope. The image captures the ultraviolet atmosphere of a star with a bright spot in the center. Its dimensions exceed several dozen times the earth's diameter. The temperature of this section is much higher than on the rest of the surface of the cosmic body. The origin of the spot is still unknown. It is believed that it is the result of the effect of a new physical phenomenon on the atmosphere of the star.
Orion's foot
Rigel is the brightest star in the constellation Orion. The constellations Hare and Eridanus, adjacent to the celestial image of a mythical hunter, are often identified in the sky by their close location to Rigel. Beta Orion, thanks to its brightness, serves as a guide for observers.
The crossbar is a white-blue supergiant with a visual magnitude of 0.12. The distance to the star from the Sun is approximately 860 light years. The radius of Beta Orion is inferior to Betelgeuse's similar parameter. Moreover, the luminosity of Rigel is 130 thousand times greater than that of our star. In this parameter, he is ahead of Alpha Orion.
Like Betelgeuse, Rigel is a variable star. It is characterized by an irregular cycle of changes in its magnitude from 0.3 to 0.03 with a period of about 24 days. The crossbar is traditionally considered a triple star system. Sometimes he is credited with owning the fourth component. However, indisputable evidence of its existence has not yet been obtained.
Neighbor
The Beta Orion is associated with the Witch Head Nebula. In its form, it really is very similar to the head of the sorceress in a pointed hat. This is a reflective nebula, luminous due to its proximity to the Rigel. In the pictures, the Witch's Head has a bluish tint, since particles of cosmic dust in the composition of the nebula reflect blue light better, and Rigel himself emits mainly in the blue part of the spectrum.
Evolution
Two bright stars in the constellation Orion will not always be like this. The internal processes of both will sooner or later lead to burnout of the fuel and, possibly, to an explosion - an impressive size does not contribute to a long-term existence. However, for our age they are definitely enough. According to forecasts, Betelgeuse will at least shine for another two thousand years. Then she is waiting for a collapse and an explosion. At the same time, its brightness will become comparable with the light of half or even the full moon. According to another scenario, Betelgeuse will “calmly” turn into a white dwarf. In any case, at the end of the process for the earth observer, Orion’s shoulder will go out.
The crossbar also awaits the fate of shining in the sky for a short time with a huge explosion of power. According to assumptions, his rage will be comparable to a quarter of the moon.
Other luminaries
Two bright stars in the constellation Orion are not the only clearly visible objects in this celestial pattern. The hunter's belt consists of three luminaries clearly visible from the Earth. These are Mintaka (Orion Delta), Alnitak (Zeta) and Alnilam (Epsilon). On the hunter's left shoulder is Bellatrix (Orion's Gamma), the third brightest point in the constellation. Its luminosity exceeds solar by 4 thousand times. Among the stars available for observation with the naked eye, Bellatrix stands out with significant surface heating. Its temperature is estimated at 21 500º K.
Nebula and black hole
Two more bright stars in the constellation Orion are located just below the Belt and belong to the Sword of the hunter. These are Theta and Iota Orion. Between them, a third object is noticeable, which, unknowingly, can also be attributed to the number of stars. However, this is the Great Orion Nebula, which seems to be a small blurry spot from Earth. New luminaries are constantly emerging here. The black hole closest to the Earth is supposedly located right here , mass surpassing the Sun by 100 times.
No less than M42, the Torch and Horsehead nebulae are also famous, also located in the constellation Orion. The first one really looks like flames rising over a fire, for which it got its name. The Horsehead Nebula also formally justifies the name. In the pictures, the silhouette of the horse is clearly visible. It seems like she is about to jump further. The horse's head belongs to reflective nebulae: in itself, it does not emit light. An opportunity to admire her is provided by the background serving the IC 434 nebula. She highlights a dark neighbor.
In numerous telescope photographs, the constellation Orion is often visible. Interesting objects: stars, nebulae, gas clouds and cosmic dust - amaze with their beauty in photographs. However, from the Earth the silhouette of a hunter seems no less impressive. Such an abundance of bright and accessible for observation with the naked eye objects is not typical, perhaps, for no more celestial images.
Those who want to see all the beauties that the mythical hunter hides can take advantage of numerous astronomy resources that allow them to study the constellation Orion: Astrogalaxy, Google Sky map , Google Earth service.