A Tale of Two Stars: The Inside Story of Orion's Belt A Tale of Two Stars: The Inside Story of Orion's Belt By Joe Rao, SPACE.com Skywatching Columnist | February 14, 2012 02:43pm ET MORE Orion is the brightest and most beautiful of the winter constellations. Some of its stars, including Betelgeuse and Rigel, are among the brightest stars. Credit: Starry Night Software Standing upright and shining down upon Earth on these midwinter nights is the brightest and grandest of all the constellations: Orion, the Mighty Hunter. Currently, Orion can be easily seen by skywatchers with clear weather as a star pattern standing high in the southern sky at around 8 p.m. local time. Three bright stars in line in the middle of a bright rectangle decorate Orion's belt , which points northward to the clusters of the Hyades and Pleiades of Taurus, and southward to the Dog Star, Sirius. Above and below the belt, we also find two immense stars, Rigel and Betelgeuse .

Rigel (the "Left Leg of the Giant"), is a blue-white supergiant star, one of the rarest breeds in our galaxy. But with their enormous brilliance — up to 100,000 times as bright as the sun — blue-white supergiants remain conspicuous over great distances. In contrast, red supergiants like Betelgeuse ("The Armpit of the Giant") are gigantic bloated globes of cooler gas. If such a star were to replace the sun in the solar system, it might extend beyond Mars' orbit. [ Gallery: The Splendor of the Orion Nebula ] Star at its prime Rigel is one of the most intrinsically luminous of all stars and one of the hottest, apparently just reaching the prime of its life in the time span of a star and literally "burning the candle at both ends." It has been computed that Rigel's luminosity is something like 57,000 times that of the sun. The star is about 773 light-years away. In stark contrast, bright red Betelgeuse is near the end of its career . It is located 522 light-years away, but does not shine with a steady light.

Betelgeuse is a "pulsating" star , expanding and contracting spasmodically with a diameter that varies from 550 to 920 times that of the sun, but so irregular are these pulsations that no one can predict exactly when it will expand or contract. In trying to describe Betelgeuse many years ago, Henry Neely, a lecturer at New York's Hayden Planetarium, once noted that it is "like an old man with his strength almost entirely spent, panting in the asthmatic decrepitude of old age." Stars produce their energy by fusing hydrogen into helium deep within their cores. When a star accumulates sufficient helium in its core, its energy output increases significantly, and it swells into a red giant or supergiant, like Betelgeuse. This is what Rigel will become in a few million years. In such stars, the core produces successively heavier elements to balance the incessant crush of gravity. But once the core begins creating iron, a star's days are numbered; the formation of elements heavier than iron consumes rather than produces energy.

Eventually, since the core can no longer support the star's vast weight, it collapses, triggering a cataclysmic supernova explosion. Betelgeuse is in its final stage and could explode in only a few million years. Skywatcher Per-Magnus Heden wondered if the Vikings gazed at the same starry sky, which includes the constellation Orion at bottom, when he took this photo in Feb. 2011. Credit: P-M Hedén/TWAN Rigel | star | Britannica.com Rigel Betelgeuse Rigel, also called Beta Orionis, one of the brightest stars in the sky, intrinsically as well as in appearance. A blue-white supergiant in the constellation Orion , Rigel is about 870 light-years from the Sun and is about 47,000 times as luminous. A companion double star , also bluish white, is of the sixth magnitude . The name Rigel derives from an Arabic term meaning “the left leg of the giant,” referring to the figure of Orion. Rigel and the Witch Head Nebula (right).

NASA/STScl Digitized Sky Survey/Noel Carboni Learn More in these related articles: star (astronomy) any massive self-luminous celestial body of gas that shines by radiation derived from its internal energy sources. Of the tens of billions of trillions of stars composing the observable universe, only a very small percentage are visible to the naked eye. Many stars occur in pairs, multiple systems,... constellation in astronomy, any of certain groupings of stars that were imagined—at least by those who named them—to form conspicuous configurations of objects or creatures in the sky. Constellations are useful in tracking artificial satellites and in assisting astronomers and navigators to locate... Orion (constellation) in astronomy, major constellation lying at about 5 hours 30 minutes right ascension and 0° declination, named for the Greek mythological hunter. Orion is one of the most conspicuous constellations and contains many bright stars. One of these, Betelgeuse, a variable star, is easily...

3 References found in Britannica Articles Assorted References stars of Orion (in Orion (constellation) ) External Links Rigel - Student Encyclopedia (Ages 11 and up) The seventh brightest star in the night sky is Rigel, or Beta Ori. It is one of the 57 stars of celestial navigation and the brightest star in the constellation Orion. Orion is situated on the celestial equator and is visible from almost any part of the world. Located approximately 10 degrees south of Orion’s belt, Rigel marks Orion’s left heel in depictions of the great hunter. Rigel is situated diagonally across from the red supergiant star Betelgeuse, which marks Orion’s right shoulder. Rigel is at its highest in the sky on January 25 at 10:00 PM when viewed from the middle latitudes. Article History Corrections? Updates? Help us improve this article! Contact our editors with your feedback. MEDIA FOR: You have successfully emailed this. Error when sending the email. Try again later. Edit Mode Submit Tips For Editing We welcome suggested improvements to any of our articles. You can make it easier for us to review and, hopefully, publish your contribution by keeping a few points in mind.

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Close Date Published: August 21, 2012 URL: Access Date: January 20, 2017 Share Rigel, Betelgeuse stars of Orion - News - Republican Herald Rigel, Betelgeuse stars of Orion POLL Are you insured through the Affordable Care Act? Yes by Mike Lynch / Published: January 16, 2011 Article Tools – + Share This The majestic constellation Orion the Hunter is now well above the eastern horizon after evening twilight. After the Big Dipper, it's the most recognizable stellar picture in the sky. Without too much imagination, you can see how the ancients saw it as a giant hunter. At a glance, it reminds me of a bowtie or an hourglass in the eastern heavens. That hourglass, according to Greek and Roman mythology, outlines the torso of the mighty nocturnal hermit hunter Orion. The constellation is best noted by the three bright stars in a row that make up his belt: Alnitak, Alnilam and Mintaka. Below and to the right of the belt is the famous Great Orion Nebula, visible even to the naked eye.

It's a colossal cloud of hydrogen gas more than 1,500 light years away, where hundreds and hundreds of young stars have and will be born. With even a small telescope you can easily see four stars in the middle of the nebula, arranged in a trapezoid, that were born from what astronomers call M-42. In the coming weeks, I want to feature the Orion Nebula in more detail in Starwatch. This week, I want to tell you about Orion the Hunter's brightest stars, Rigel and Betelgeuse, that are anchored at opposite corners of Orion. They are the 4th and 5th brightest stars in our Shamokin and Pottsville skies. Nowhere else in our night sky will you see two stars this bright and so close to each other. Physically they're nowhere near each other, but they seem that way because both of these bright shiners are located in nearly the same direction from Earth. That's why they can both be in the same constellation, Orion.

Rigel is a super blue giant star, and Betelgeuse is a super-duper red giant star, and even with the naked eye, you can see their color tinges, especially with Betelgeuse. Rigel Rigel is the brightest star in Orion, slightly outshining Betelgeuse even though, according to classic star charts, Betelgeuse is considered the alpha or brightest star in the great constellation. Truthfully, there isn't much difference in their brightness, and it's easy to understand how that mistake could have been made. Rigel is somewhere between 700 and 800 light years away from earth with one light year, the distance that light travels in one year's time, equaling almost 6 trillion miles. The sun, our closest star, is less than a hundred million miles away by comparison. Despite being trillions and trillions of miles away, Rigel is so bright in our winter sky because it's 60 million miles in diameter, making it 100 times the diameter of our sun and 17 times the mass of our comparatively diminutive home star.

Most astronomers believe Rigel kicks out more than 80,000 times more light than our sun, making it the most luminous star in our part of the Milky Way Galaxy. Its outer layer has an estimated temperature just under 20,000 degrees Fahrenheit that makes it almost twice as hot as our sun. Without a doubt, Rigel is one big shiner, but there's a price to be paid for all that stellar prowess. Heavier stars like Rigel don't live nearly as long as smaller stars like our sun. They're gas guzzlers, going through the hydrogen fuel in their cores at highly prodigious rates. It's hard for the best of astronomers to estimate the exact age of a particular star since there are so many factors to consider. The mass of the star is the main contributor to a stars life span, and the best indications are that Rigel's total light time is less than one billion years. By comparison, our own sun sips its nuclear fuel and is expected to have a total life expectancy of around twelve billion years. That being the case Rigel hasn't even been around for all that long.

When dinosaurs roamed around our world, Rigel was not yet in our starry sky, and it will be out of the heavens as we know them before our sun calls it a lifetime. Betelgeuse At the other corner of Orion is without a doubt the biggest single thing you've ever seen, Betelgeuse. It's more than 20 times the mass and more than 1,100 times the diameter of our sun, giving Betelgeuse an estimated girth of about one billion miles across. It's so large that if you put it in the place of our sun in our solar system, the planets Mercury, Venus, Earth, Mars and even Jupiter would be living inside Betelgeuse. Betelgeuse's diameter and reddish hue are due to the fact that it's already near the end of its very short life. Most astronomers estimate that Betelgeuse isn't much more than a few million years old and it's already expended its hydrogen and helium fuel to the point where it's puffed out in the red giant phase of its brief life.

No one really knows for sure, but in maybe less than 10,000 years, a thousand years, or even next year, it could blow itself up in a tremendous supernova explosion, making it brighter than the full moon in our night skies for several weeks. It's a good thing that Betelgeuse is more than 400 light years away from Earth because if it was much closer, it could make for a really bad day here on Earth. In fact, it's believed by many astronomers that if Betelgeuse exploded within a hundred light years of Earth, the radiation from the blast could change or eliminate life as we know it on our planet. Keep your distance, Betelgeuse! (Lynch is an amateur astronomer and author of the book, "Pennsylvania Starwatch.) We welcome user discussion on our site, under the following guidelines: To comment you must first create a profile and sign-in with a verified DISQUS account or social network ID. Sign up here. Comments in violation of the rules will be denied, and repeat violators will be banned. Please help police the community by flagging offensive comments for our moderators to review. By posting a comment, you agree to our full terms and conditions.

Click here to read terms and conditions . Betelgeuse - Alpha Orionis | Constellation Guide Constellation Guide Constellations: A Guide to the Night Sky Betelgeuse by admin Betelgeuse, Alpha Orionis, is the second brightest star in Orion constellation and the ninth brightest star in the sky. It is a supergiant star, distinctly red in colour, located at an approximate distance of 643 light years from Earth. It is an evolved star, one expected to explode as a supernova in a relatively near future. Betelgeuse is a large, bright, massive star easily found in the sky in the winter months because it is part of a familiar pattern formed by the celestial Hunter. The red supergiant marks one of Orion ‘s shoulders, while the hot, bright giant Bellatrix, Gamma Orionis, marks the other. Betelgeuse is a variable star and, as its brightness changes, the star has been known to outshine the constellation’s brightest star, the blue supergiant Rigel, Beta Orionis.

Alpha Orionis’ traditional name, Betelgeuse, originated in the Arabic phrase Yad al-Jauzā’, meaning “the shoulder of the central one” or “the hand of Orion,” referring to the star’s position in the constellation. The phrase al-Jauzā’ is the traditional Arabic name for Orion constellation . It can be loosely translated as “the central one,” referring to a mysterious woman. The modern Arabic name for the constellation is al-Jabbār, meaning “the giant.” With the phrase Yad al-Jauzā’, Medieval translators misread the Arabic character for Y as B, which resulted in a mistranslation into “armpit of the giant.” The name Betelgeuse can be pronounced /ˈbiːtəldʒuːs/, /ˈbiːtəldʒuːz/, or /ˈbɛtəldʒuːz/. The original pronunciation is uncertain. Position of Betelgeuse in the constellation of Orion. Image: Akira Fujii Betelgeuse and Bellatrix mark the two shoulders of Orion, the Hunter . Betelgeuse, marking the right shoulder, lies in the upper left corner of the constellation from our point view.

It is one of the largest and most luminous stars known. Placed at the centre of our solar system, Alpha Orionis would extend beyond the asteroid belt, all the way to the orbit of Jupiter and possibly beyond. Betelgeuse belongs to the spectral class M2Iab. The M refers to the star’s colour, red, and the ‘Iab’ suffix indicates that the star is an intermediate luminosity supergiant. It has an absolute magnitude of roughly -6.02. The star’s mass is uncertain, but estimates range from 7.7 to 20 times that of the Sun. As a result of its high mass, Betelgeuse has evolved quickly and, even though it is less than than 10 million years old, it is nearing the end of its life cycle. The star is believed to have an average luminosity about 120,000 times that of the Sun. Betelgeuse is classified as a semi-regular variable star. Its apparent magnitude varies from 0.2 to 1.2 over a period of about 400 days, which is the widest magnitude range for a first magnitude star.

Because it varies in magnitude, Betelgeuse occasionally surpasses Procyon in Canis Minor in brightness and becomes the seventh brightest star in the sky. When at its brightest, Betelgeuse outshines Rigel, the brightest star in Orion , and becomes the sixth brightest star in the sky. At its faintest, it drops below Deneb , the brightest star in Cygnus , and shares the position of the 20th brightest star with Mimosa, Beta Crucis, located in Crux constellation and one of the stars that form the Southern Cross . Betelgeuse is a pulsating red supergiant showing low-amplitude variations and periods of stable brightness. The star’s pulsations result in its absolute magnitude varying from -5.27 to -6.27. As its outer layers expand and contract, the surface increases and decreases, and the temperatures rises and falls. Betelgeuse pulsates because it has an unstable stellar atmosphere. When it contracts, it absorbs more of the energy that passes through it. As a result, its atmosphere heats up and expands. When the star expands, the atmosphere becomes less dense and cools down, which leads to another period of contraction.

This collage shows the Orion constellation in the sky (Betelgeuse is identified by the marker), a zoom towards Betelgeuse, and the sharpest ever image of this supergiant star, which was obtained with NACO on ESO’s Very Large Telescope. Image: ESO, P.Kervella, Digitized Sky Survey 2 and A. Fujii There are several cycles to the star’s pulsations, with short-term variations of roughly 150 to 300 days, and longer, cyclic variations over a period of about 5.7 years. As a result of the star’s variability, limb darkening, angular diameter that tends to vary with wavelength, and the star’s tendency to occasionally change shape, many of Betelgeuse’s properties are still uncertain. Because the star is rapidly losing mass, its surface is obscured by a large envelope of ejected material, approximately 250 times larger than the star itself, which makes measurements even more difficult. In 1985, two close companions were discovered in orbit around Betelgeuse, but have not been confirmed by research in the years since.

Betelgeuse is easy to find in the sky because it is part of a prominent winter constellation, Orion the Hunter . From mid-September to mid-March, the star is visible from almost any location on the globe, with the exception of those south of 82°S. For observers in the northern hemisphere, Betelgeuse rises in the east just after sunset in January. In March, it is due south early in the evening. By May, the star only briefly shows up on the western horizon after sunset. In the early summer, it travels behind the Sun and can’t be seen. A few months later, it can be seen appearing on the eastern horizon just before dawn. In June and July, Betelgeuse can’t be seen at night at all, only using a telescope in daylight. Supernova Betelgeuse has reached a late stage of evolution and is expected to end its life in a supernova explosion at some point within the next million years. The red supergiant will most likely explode as a Type II supernova.

The supernova may brighten to a visual magnitude of -12 over a couple of weeks, which would make it outshine the Moon, cast shadows in the night, and be visible in daylight. The supernova would stay at that intensity for two to three months before dimming. The last bright supernova, SN 1987A, was visible to the naked eye even though the progenitor star wasn’t even in our galaxy, but in the nearby Large Magellanic Cloud in Dorado constellation , roughly 168,000 light years away from the solar system. While Betelgeuse is far too distant to do any damage to Earth, when it explodes, it will certainly give us a very bright spectacle in the sky. Earth will most likely not be affected by the explosion because Betelgeuse’s rotational axis is not pointed toward our planet and the gamma ray burst sent by the supernova will most likely not cause any damage to our ecosystems. Neutrinos and other forms of radiation will not reach us until 600 years after the explosion and will not affect terrestrial life. Supernovae generally must be within 25 light years to cause any significant damage to Earth.

At 643 light years, Betelgeuse is more than 25 times that distance. Betelgeuse has evolved off the main sequence and has expanded and cooled to become a red supergiant. Even though it is a relatively young star, it has likely used up the hydrogen at its core, which is causing the star to contract, its temperature to rise, and its density to increase. Consequently, Betelgeuse has started fusing helium into carbon and oxygen. At some point, the star will collapse and explode. Most likely, it will leave behind a neutron star roughly 20 kilometres in diameter. Mass is a key factor when predicting how a star will end its life. The exact mass of Betelgeuse is uncertain, but most astronomers who have investigated the star agree that it has more than 10 solar masses. If its mass and rotation speed are sufficient, Alpha Orionis may even evolve into a yellow hypergiant or a luminous blue variable before the supernova event. FACTS Betelgeuse is part of two familiar winter asterisms. It marks the upper right vertex of the Winter Triangle .

The stars of the Winter Triangle and the Winter Hexagon The other two stars that form the Winter Triangle are Procyon in Canis Minor and Sirius in Canis Major . Betelgeuse also lies at the centre of the Winter Hexagon , formed by Sirius , Procyon, Pollux in Gemini , Capella in Auriga , Aldebaran in Taurus , and Rigel in Orion constellation . In 2013, scientists said that Betelgeuse would likely crash into a “cosmic wall” of interstellar dust in several thousand years. The star’s solar wind is expected to reach the wall in about 5,000 years and the star itself is expected to crash into the bar roughly 12,500 years after that. The bar is thought to be either a linear filament linked to the Milky Way’s magnetic field or the edge of an interstellar cloud lit by Betelgeuse. Alpha Orionis originated in the Orion OB1 Association, a group of stars whose members include the stars of Orion’s Belt , which share the same proper motion and velocity through space.

The red supergiant is believed to have changed its course and motion through space at some point because its projected pathway does not seem to intersect with any star forming region. The most likely scenario is that it is a runaway member of the Orion OB1 Association, formed some 10-12 million years ago in a molecular cloud in Orion . This picture of the dramatic nebula around the bright red supergiant star Betelgeuse was created from images taken with the VISIR infrared camera on ESO’s Very Large Telescope (VLT). This structure, resembling flames emanating from the star, forms because the behemoth is shedding its material into space. The earlier NACO observations of the plumes are reproduced in the central disc. The small red circle in the middle has a diameter about four and half times that of the Earth’s orbit and represents the location of Betelgeuse’s visible surface. The black disc corresponds to a very bright part of the image that was masked to allow the fainter nebula to be seen. Image: ESO, VLT, P. Kervella Betelgeuse moves through space at a speed of 30 km/s.

As a result, its stellar wind has created a bow shock more than 4 light years wide. The wind is ejecting vast amounts of gas into space at a rate of 17 km/s, heating up the material around the star. Consequently, it is visible in infrared wavelengths. The bow shock was first imaged in 1997. Its cometary structure is believed to be at least one parsec wide if the star’s estimated distance of 643 light years from the solar system is accurate. The bow shock is estimated to be less than 30,000 years old. Alpha Orionis is the brightest near-infrared source in the sky. It has a J band magnitude of -2.99. Only 13 percent of the star’s energy is emitted in visible light. The star’s variability was first noted by John Herschel in 1836. He published his notes in Outlines of Astronomy. Over the next four years, Herschel noticed that Betelgeuse was showing considerable changes in magnitude. In October 1837, it outshone Rigel, the brightest star in Orion , and did it again in November 1839.

The variations in brightness may have been the reason why Johann Bayer gave Betelgeuse the designation Alpha in his Uranometria, published in 1603, even though it is usually not as bright as Rigel, designated Beta Orionis. Betelgeuse was the first star other than the Sun to have its disk imaged in optical and infrared wavelengths, by John E. Baldwin and his colleagues at the Cavendish Astrophysics Group. Alpha Orionis is believed to have started its life as a hot, blue class O star some 10 million years ago. The star had an initial mass about 18-19 times that of the Sun. The spelling of the name Betelgeuse did not become universal until the early 20th century. Before that, the star’s name was spelled Betelgeux or Betelgeuze. Photo taken by Rogelio Bernal Andreo in October 2010 of the Orion constellation showing the surrounding nebulas of the Orion Molecular Cloud complex. Also captured is the red supergiant Betelgeuse (top left) and the famous belt of Orion composed of the OB stars Altitak, Alnilam and Mintaka.

To the bottom right can be found the star Rigel. The red crescent shape is Barnard’s Loop. The photograph appeared as the Astronomy Picture of the Day on October 23, 2010. Image: Rogelio Bernal Andreo Betelgeuse has had many different names across the cultures, including the Sanskrit Bahu, reflecting the Hindu view of the Orion constellation as a running stag or antelope, the Persian Bašn (“the Arm”), and Coptic Klaria (“an Armlet”). The Chinese knew the star as Shēnxiùsì, the Fourth Star of the constellation of Three Stars, referring to the stars forming Orion ‘s girdle. The constellation was later expanded to include ten stars. In Japan, Alpha Orionis was known as Heike-boshi, referring to the Heike clan, which adopted the star and its red colour as its symbol. Tahitian observers considered Betelgeuse to be one of the pillars holding the sky. They knew the star as Anâ-varu. In Hawaii, the star was known as Kaulua-koko, which means “brilliant red star.” In cultures across the Americas, the star is often seen as a severed limb.

The Taulipang of Brazil called the constellation Zililkawai, and it represented a hero whose leg was severed by his wife. The star’s blinking light represented the severing of the leg. The Lakota people saw it as a chief with a severed arm. In northern Australia, the Wardaman people called Betelgeuse Ya-jungin, meaning “Owl Eyes Flicking.” In South Africa, the star represented a lion stalking three zebras, marked by Alnilam, Alnitak, and Mintaka, the stars of Orion’s Belt . In Macedonian legend, Betelgeuse was associated with Orach, “the ploughman,” while the rest of Orion constellation represented a plough with oxen. Image of the supergiant star Betelgeuse obtained with the NACO adaptive optics instrument on ESO’s Very Large Telescope. The use of NACO combined with a so-called “lucky imaging” technique, allowed the astronomers to obtain the sharpest ever image of Betelgeuse, even with Earth’s turbulent, image-distorting atmosphere in the way.

The resolution is as fine as 37 milliarcseconds, which is roughly the size of a tennis ball on the International Space Station (ISS), as seen from the ground. The image is based on data obtained in the near-infrared, through different filters. The field of view is about half an arcsecond wide, North is up, East is left. Image: ESO/P. Kervella Betelgeuse has also been mentioned in numerous films, television shows, novels, and other works of fiction. In Tim Burton’s 1988 feature Beetlejuice, an undead bio-exorcist played by Michael Keaton shares the star’s name. In The Hitchhiker’s Guide to the Galaxy, Betelgeuse was the home system of Zaphod Beeblebrox, the Galactic President. In The Cthulhu Mythos, the star is the home of the Elder Gods. Betelgeuse has also been notably mentioned in Jean Louis De Esque’s poetic work Betelguese, a trip through hell (1908), Muhammad Barker’s Tékumel novels and games, Philip K.

Dick’s short stories “Tony and the Beetles” (1953) and “Shell Game” (1954), Kurt Vonnegut, Jr.’s novel The Sirens of Titan (1959), Pierre Boulle’s novel Planet of the Apes (1963), Gérard Klein’s Le Gambit des Etoiles (1958), Frank Herbert’s Dune series (as Bela Tegeuse), Isaac Asimov’s The Robots of Dawn (1983), Robert J. Sawyer’s Calculating God (2000), and Jeffrey Carver’s From a Changeling Star (1989). Betelgeuse is also mentioned in the games BattleTech, Star Control II, Frontier: Elite II, and Frontier: First Encounters. Size The size of Betelgeuse is difficult to determine, but its diameter is believed to change from 550 to 920 times the Sun’s diameter. The star is large enough that it reveals a disk when seen in the best telescopes.

This artist’s impression shows the supergiant star Betelgeuse as it was revealed thanks to different state-of-the-art techniques on ESO’s Very Large Telescope, which allowed two independent teams of astronomers to obtain the sharpest ever views of the supergiant star Betelgeuse. They show that the star has a vast plume of gas almost as large as our Solar System and a gigantic bubble boiling on its surface. These discoveries provide important clues to help explain how these mammoths shed material at such a tremendous rate. The scale in units of the radius of Betelgeuse as well as a comparison with the Solar System is also provided. Image: ESO/L. Calçada The star’s diameter was measured in 2000 using the Infrared Spatial Interferometer (ISI) and the calculations yielded a radius of 3.6 astronomical units. In June 2009, Charles Townes, Nobel Laureate and inventor of the laser, announced his discovery that Betelgeuse had shrunk by 15 percent since 1993, without losing brightness. The contraction was likely a result of shell activity in Betelgeuse’s extended atmosphere.

Astronomers have pinpointed at least six shells around the star. Betelgeuse was observed ejecting a vast amount of gas in July 2009, with distances roughly equalling 30 astronomical units. Alpha Orionis was the second star after the Sun to have the angular size of its photosphere measured. It was measured on December 13, 1920 by Albert Michelson and Francis Pease at Mount Wilson Observatory. They measured the star’s angular diameter at 0.047”, which translated into a diameter of 2.58 astronomical units. However, these numbers are uncertain because of limb darkenining and measurement errors. Estimates over the years have ranged from 0.042 to 0.069 arcseconds and a projected radius of the stellar disk between 1.2 and 8.9 astronomical units. The star’s diameter is difficult to determine for several reasons. First, because Alpha Orionis is a pulsating variable, which means that its diameter changes over time. Second, because it is difficult to determine a definable ‘edge’ of the star because limb darkening causes its optical emissions to vary in colour.

Third, because it is also hard to define the star’s photosphere because it is surrounded by a a thick gaseous envelope made up of material ejected by the star which absorbs and emits light. As a result, the measured diameter changes depending on the wavelength used to measure it. Comparison of size of Betelgeuse (largest dull-red sphere inside Jupiter’s orbit) and R Doradus (red sphere shown inside Earth’s orbit) together with the orbits of Mars, Venus and Mercury and the stars Rigel and Aldebaran from Image:1e10m comparison Rigel, Aldebaran, and smaller – antialiased no transparency.png, to scale. The faint yellow sphere centred on the Sun has a radius of one light-minute. The yellow ellipses represent the orbits of each planet. Image: Paul Stansifer and 84user at wikipedia.org Betelgeuse was once thought to have the largest angular diameter of any star. However, after a team of astronomers measured the diameter of R Doradus at 57.0 mas. in 1997, the star lost this distinction.

It is now considered to be in third place even though R Doradus, a Mira variable located in Dorado constellation and much closer to Earth at less than 200 light years, has a diameter only about a third that of Alpha Orionis. Betelgeuse’s estimated radius is about 5.5 astronomical units, which makes the star around 1,180 times larger than the Sun. With the observed contraction, the star’s radius has shortened to 4.6 astronomical units. Distance Betelgeuse lies at a distance of 643 light years or 197 parsecs from Earth. Earlier estimates of the star’s distance were 430 light years (131 parsecs) in 1997, and 520 light years (152 parsecs) in 2007. The star’s exact distance is uncertain because direct parallax measurement results in a distance of about 495 light years, while the parallax using the natural radio emission yields about 640 light years. Sometimes the middle distance – 570 light years – is cited.

In 2008, Graham Harper and colleagues used the Very Large Array (VLA) and came up with radio data that yielded a distance of 643 light years. Colour Alpha Orionis has a colour index (B–V) of 1.85, which makes it a very red star. This image is a colour composite made from exposures from the Digitized Sky Survey 2 (DSS 2). The field of view is approximately 2.0 x 1.5 degrees. Image: ESO/Digitized Sky Survey 2 The star’s photosphere has an extended atmosphere. As a result of being surrounded by a thick envelope of gas, the star’s extended atmosphere exhibits strong lines of emission rather than absorption. It has been known to move away and toward the star as a result of radial velocity fluctuations in the photosphere. The star’s red colour has been documented since antiquity. The Greek astronomer Ptolemy described it as ruddy (ὑπόκιρρος – hypókirros) in the 2nd century. Three centuries before Ptolemy’s observations, Chinese astronomers noted that the star had a yellow coloration.

This indicates that Betelgeuse may have been a yellow supergiant just before the beginning of the common era. Temperature The temperature of the star’s surface is estimated to be between 3,140 and 3,641 K. The estimated temperature of the star’s atmosphere is around 3,450 K. The gas around the star gradually cools as it expands away from the star.

Betelgeuse – Alpha Orionis Coordinates: 05h 55m 10.3053s (right ascension), +07°24’25.426” (declination) Spectral class: M2Iab Apparent magnitude (visible spectrum): 0.42 (0.3 to 1.2) Apparent magnitude: (J band): -2.99 ± 0.10 Absolute magnitude: -6.02 Distance: 643 ± 146 light years (197 ± 45 parsecs) Variable type: SR c (semi-regular variable) Mass: 7.7 – 20 solar masses Radius: 950 – 1,200 solar radii Luminosity: 120,000 ± 30,000 solar luminosities Temperature: 3,140 – 3,641 K Age: 7.3 million years Pronunciation: /ˈbiːtəldʒuːs/, /ˈbiːtəldʒuːz/, or /ˈbɛtəldʒuː

z/ Designations: Betelgeuse, Alpha Orionis, α Orionis, 58 Orionis, HR 2061, BD +7° 1055, HD 39801, FK5 224, HIP 27989, SAO 113271, GC 7451, CCDM J05552+0724AP, AAVSO 0549+07 VIDEO Betelgeuse and Rigel Betelgeuse and Rigel Pin it – Betelgeuse and Rigel are the brightest stars in the constellation Orion.

They are easily seen above and below the famous belt and sword. Betelgeuse, the 9th brightest star in the sky, is a red supergiant. As one of the largest known stars, Betelgeuse is truly a giant – 14 times more massive than our sun and 800 times its diameter. Betelgeuse is so large that it could contain over 1 and a half billion of our suns. If placed in the center of our solar system, the outer surface of Betelgeuse would extend almost to the orbit of Jupiter – engulfing Mercury, Venus, Mars and the Earth. Sirius, just outside the constellation Orion is the brightest appearing star in the night sky, however, the size of Sirius is vastly smaller than that of Betelgeuse. So why isn’t Betelgeuse much brighter than Sirius? Because it is thought to be around 80 times farther away. Marking the heel of Orion, we find the blue white star Rigel, the 7th brightest star in the sky.

Some 1400 light years away, Rigel, also considered a supergiant, is 17 times more massive than our sun and 50,000 times brighter. What we see in the sky is actually two stars, a binary system, and is composed of one very large, super-bright star, and a small, fainter star, only observable by larger telescopes. The light from Rigel illuminates a nearby reflection nebula sometimes called the Witch Head Nebula because of its peculiar shape that resembles a fairytale witch. The blue color of the nebula is not only a result of reflected blue light from Rigel – but is also due to the fact that the dust particles that make up the nebula are thought to reflect blue light more than red. Have you ever wondered why our daytime sky is blue? It’s for the same reason. The dust in our atmosphere more efficiently reflects blue light. How far away are the stars of Orion? Scientists are really not sure. They estimate the distance at over 600 light years.

Traveling at the speed of our fastest spacecraft – some 40,000 miles per hour – it would take us over 10 Million years to reach the bright stars of Orion. The book of Isaiah tells us that the LORD created the heavens, and stretched them out. The vast universe gives us just a glimpse of His creative power. I’m David Rives Betelgeuse and Rigel | The Creation Club | A Place for Biblical Creationists to Share and Learn David Rives By David Rives Betelgeuse and Rigel are the brightest stars in the constellation Orion. They are easily seen above and below the famous belt and sword. Betelgeuse, the 9th brightest star in the sky, is a red supergiant. As one of the largest known stars, Betelgeuse is truly a giant – 14 times more massive than our sun and 800 times its diameter. Betelgeuse is so large that it could contain over 1 and a half billion of our suns. If placed in the center of our solar system, the outer surface of Betelgeuse would extend almost to the orbit of Jupiter – engulfing Mercury, Venus, Mars and the Earth.

Sirius, just outside the constellation Orion is the brightest appearing star in the night sky, however, the size of Sirius is vastly smaller than that of Betelgeuse. So why isn’t Betelgeuse much brighter than Sirius? Because it is thought to be around 80 times farther away. Marking the heel of Orion, we find the blue white star Rigel, the 7th brightest star in the sky. Some 1400 light years away, Rigel, also considered a supergiant, is 17 times more massive than our sun and 50,000 times brighter. What we see in the sky is actually two stars, a binary system, and is composed of one very large, super-bright star, and a small, fainter star, only observable by larger telescopes. The light from Rigel illuminates a nearby reflection nebula sometimes called the Witch Head Nebula because of its peculiar shape that resembles a fairytale witch. The blue color of the nebula is not only a result of reflected blue light from Rigel – but is also due to the fact that the dust particles that make up the nebula are thought to reflect blue light more than red.

Have you ever wondered why our daytime sky is blue? It’s for the same reason. The dust in our atmosphere more efficiently reflects blue light. How far away are the stars of Orion? Scientists are really not sure. They estimate the distance at over 600 light years. Traveling at the speed of our fastest spacecraft – some 40,000 miles per hour – it would take us over 10 Million years to reach the bright stars of Orion. The book of Isaiah tells us that the LORD created the heavens, and stretched them out. The vast universe gives us just a glimpse of His creative power. I’m David Rives Truly – The Heavens Declare the Glory of God LIKE David’s FB page here: FOLLOW us on Twitter: VISIT our official website for tons of free information: David Rives MUSIC: For the TBN show “Creation in the 21st Century”: Don't you think others need to learn about this? Help us share this content with your friends by using the links below: Identify Constellations - AstroEd AstroEd Identify Constellations From AstroEd This session is to help you learn to identify bright stars and constellations in the night sky.

These resources may be useful in the lab, or for later study. Weekly guide and news For your laptop, home computer, cell phone, or tablet there are many choices. iTunes also offers a Sky Map for iPhone and iPad for a fee. If want to pursue this and learn the night sky well, old technology works great. Consider getting a planisphere star finder , a rotating map of the sky that will show you how it appears on any date and time. This lab will use Stellarium to help you learn to identify some of the prominent constellations and bright stars. If you have a Planisphere or one of the other applications on your handheld device or laptop, use it too. Contents 7 Constellations seen from the Southern Hemisphere by Season Getting Started First, there are a few things you need to know about using Stellarium. You might look at the Stellarium Tour on their website for an overview and reference to these options: Screen mode Stellarium starts in full screen mode and will cover everything. You can change this by pressing the F11 key to fit it into a smaller window. Menu bars There are two bars of menus, one at the bottom of the screen, and one on the left.

They are hidden until you run the mouse down to the bottom or over to the left. Quitting When you or done, you can use the bottom menu bar to exit by selecting the off button. Setting your location By default you will be in Paris, France. If you press F6 the location menu will pop up and you can select your city or put in longitude and latitude. Once you have done this and saved the configuration, Stellarium will come up at your chosen site. The location menu is also in the left menubar under the compass icon at the top left. When you have selected your location the menu will show a map of Earth with an arrow pointing to your site. Setting the time Stellarium starts with the sky over your site at this very moment. The date and time will show at the lower right, based on the computer's clock. This time is the local time at your computer. If you change your location, the time shown will still be the time at your computer, not the time at the new site. For example, if you are in Baltimore, Maryland and you set up Stellarium for that site, then the computer is in the Eastern U.S. time zone.

When you run Stellarium at 3 PM it will show the afternoon daytime sky with the Sun. Should you use the location menu to change to Rome, Italy, the sky will go dark because it's nighttime there. The clock will still show 3 PM because that's the time where you are. You can change the date and time in two ways. One is with the time menu selected from the left menu bar Clock icon. The other is with the two arrow icons at the right of the bottom menu bar. These speed forward-reverse, real time rate, and now buttons let you speed up the daily motions of the sky, and then slow them down again when you have the events in view you want to see. Looking around Change the direction you are looking by holding down the left mouse button and dragging your direction of view, or by using the updown leftright arrow keys on the keyboard. Identifying planets, stars, and constellations The lower menu offers options to add labels. By default the planets will be named, and you can turn this off using the Planets labels icon that looks like Saturn.

You can outline the bright stars of the constellations, add constellation names, and even overlay mythological figures to help you see the patterns by clicking on the various buttons in this menu. There are two celestial grids offered too that show the equatorial celestial coordinates of stars (right ascension and declination), and the local sky coordinates (altitude and azimuth). A menu on the left for Sky and viewing options allows you to change the constellations, names and associated cultural folklore. Click that option, select Starlore and Western to see the the typical sky labels of American and European culture, or change to one of the others offered to see the diversity of named patterns in the sky. The same menu under Markings lets you select whether you would also like to see the constellation boundaries as red dotted lines. Sometimes it's helpful to see these in order to identify the constellation in which a particular object is located. Identifying an object Move the mouse over the object and click with the left button to have its identification displayed. Click with the right button to make this go away. Click with the center button (press down on the mouse wheel) to have the display center on this object after you have selected it.

Zooming in and out The Page Up and Page Down keys on the keyboard zoom in and out of the sky. You can move around the zoomed in sky with the arrow keys or dragging with the left mouse button. The status display at the bottom of the view tells you the field of view FOV in degrees among other things. For some objects there is a photo that appears when the sky view is zoomed in close. When an object is selected and centered in the view, after zooming in the view will stay centered on it even as the day progresses. Think of it as a telescope that is pointing at your target, and tracking the target as the Earth rotates. Finding Planets The Moon and planets will be labeled by default. You can turn these names off with the P or by clicking on the Planet icon on the lower menu bar. If you select a planet with a left mouse click, the sky view will lockto that planet and you can follow it during the night. Planets with satellites like Jupiter will show the satellites as they really would appear in a telescope, and in motion in their orbits around the planet. You can find a planet or other objects by using the Search window The left menu has a Magnifying glass icon that brings up this option.

So does F3. Finding Stars and Constellations Stellarium starts with the sky as it is now, and you may run the clock forward or set the time for about an hour after sunset to see the night sky for the current season. In this lab study we will go through the seasons in sequence for the northern and the southern hemisphere, and help you find your way around the sky. The goal is to learn a few bright stars and constellations, seen from any place on Earth, and at any time of year. It's daunting task, and the patterns will at first seem confusing. We'll help you find the brightest stars, and some recognizable patterns. The key to learning this skill is to become accustomed to the patterns so that your mind's eye will recognize them, even in a sky filled with stars you do not know.At the bottom of this unit there is are lists of constellations and bright stars that are the most among the most recognizable for each each in both southern and northern hemispheres. In another lab experiment we will focus on the sky tonight, and on the planets. This one is more general and explores the stars and constellations seen from different locations on Earth.

You should set Stellarium to see the sky tonight in your own locatin to begin with, and we will advise on changing this as we go along. Bright Stars Winter begins in late December for the northern hemisphere, or late June for the southern hemisphere. You can consult the list of stars and constellations at the bottom of this unit to see what should be visible then. Let's set set the time to 7 P.M. on January 15, when the sky is dark and stars are clear and bright. If you are in the northern hemisphere make sure your location is set properly, turn your attention toward the southeast and look for the brightest stars. (If you are in the southern hemisphere, for the following pick a favorite spot a little north of the equator so that you can see stars you are familiar with, as well as the stars of the northern sky.) Sirius, the brightest star in the sky will be rising at this time. Left click on it and you'll see information about it displayed: Names: Sirius (alpha Canis Majoris) HIP 32349 Sirius is its common name. Alpha Canis Majoris means that it is the brightest star in Canis Major, the big dog.

HIP 32349 means that it is the 32,349th star of the Hipparcos catalog. Magnitude: -1.45 (B-V: 0.00) That's how bright it is on the astronomer's scale. Smaller numbers are brightest, larger ones fainter. Magnitude 6.0 is about as a faint a star as you can see without a telescope. The magnitude scale is logarithmic, and a difference of 5 on this scale corresponds to a factor of 100x in energy received each second from the star. The B-V is a measure of color, and the 0.0 for Sirius means that it looks white to the eye. A positive number is red, and a negative number is blue. Distance: 8.60 light years Sirius is 8.6 light years from the Sun. The light you see in the sky from Sirius tonight left it 8.6 years ago, when you were 8.6 years younger. Light leaving the star today will arrive in 8.6 years when you are 8.6 years older.

Find these other stars: Procyon, Rigel, Betelgeuse and Aldebaran. For each one, identify what constellation is it in, and how bright it is. 1. What constellation are Rigel and Betelgeuse in? 2. What colors are these two stars? Let time go by and watch the stars move across the sky. 3. Which of the stars Sirius, Procyon, Rigel, or Belegeuse is the one that gets highest in your sky during the night? Notice the pattern of bright stars. These are the one's you'll see first in an urban sky. Advance the date to March 5 and set the time again to about 2 hours after sunset. 4. Where are Sirius, Procyon, Rigel, Betelgeuse and Aldebaran in the sky now, compared to where they were at the same time in January? Advance the date again to June 15 and now you'll see Deneb, Vega, and Altair rising in the east. Arcturus will be nearly overhead if you are in a northern latitude. During the night the stars will move across the sky 5. About what time on June 15 will Vega be overhead?

6. What is the name of another bright star in the same constellation that Deneb is in? 7. Which one of these stars, Arcturus, Deneb, Vega, or Altair, is orange? That is, which one is a cool star of type K or M? Go forward again to the fall, and set the date to September 15. Look directly overhead if you are at northern latitude. If you are elsewhere, to answer this question set your location to a northern latitude of around 40 degrees. Three of the stars that you have identified form a distinctive pattern overhead called the Summer Triangle. 8. What are the three stars that define the "Summer Triangle" that is overhead in northern latitudes in late summer? Constellations Turn off the equatorial grid if you still have it on, and turn on the constellation names and outlines (use the lower menu or press C and V). Let's find some of the easily identified constellations in the northern sky for each season. Set the date for January 15 at 10 P.M. Orion with very bright stars Betelgeuse and Rigel are in the sky at this time.

Set the date for March 15 at 10 P.M. Gemini, the twins , with the pair of similar stars Castor and Pollux comes in to view. Set the date for June 15 at 10 P.M. Leo, the lion, with the bright star Regulus is visible. Set the date for September 15 at 10 P.M. You will see Sagittarius, the archer, that looks like a teapot. Set the date for November 15 at 10 P.M. 9. Where is Pegasus, the horse, at this time? Stellarium lets you look at fainter stars, clusters of stars, nebulae, and galaxies too. See if you can find Messier 15 (M15) in Pegasus. It is a globular star cluster about 12 billion years old containing more than 100,000 stars. M15 is about 33,000 light years away, much farther than the nearby stars that define the constellations in the night sky. 10. There is a bright star in Pegasus quite close to M15 in the sky (but not in space).

What is the name of that star, and how far from us is it? (Hint: Right click to get information on an object. This star is slightly red.) Looking from the South The following is a guided tour of the sky from the southern hemisphere to see how the sky would change if we moved our point of view to a southern latitude. From the north pole of the Earth you can see only the half of the sky that is north of the Earth's equator. Your horizon is the celestial equator. More of the southern sky becomes visible as you move southward. From the Earth's equator, the north pole of the sky is on the northern horizon and the south pole is on the southern horizon. Over 24 hours the entire sky will pass into and out of view. Imagine now going south from your current location. The farther south you go, the more of the southern sky will be overhead. Let's illustrate this. Set the date for January 15 at 10 PM by using the date and time menu "F5". Direct your view to the south and bring up the location menu with "F6".

Use the map of Earth and click on a location that's south of yours, looking for a place that is at the same latitude and about 30 to 40 degrees below the equator. The sky will update each time you click a new location on Earth. Once you have a suitable location you can close the location menu. Look for a familiar constellation that you have already identified from the northern location nearly overhead now. There is a very bright star Canopus, south of Sirius, that you could not see from a northern location in the constellation of Carina. 11. What is the magnitude of Canopus? Which is brighter, Sirius or Canopus? (Hint: Right click in Stellarium to see the more about the object. The larger the magnitude, the fainter the star. Your unaided eye can see 6th magnitude.) The bright star Achernar is not far away, a little southwest of the star you found in the question above. Set the field of view so that you can see a field of 70 to 90 degrees with Achernar on right.

(If you're lost, try using the search option and type in the name to have the software center up on the object.) There are two fuzzy clouds in the center of the field of view now. These are the Large and Small Magellanic Clouds, companion galaxies to our own Milky Way. If you need help in identifying them, the search term "SMC" in Stellarium will center the Small Magellanic Cloud. 12. What constellation is the SMC in? Zoom in and you'll find an object that is not a star, and is close to the "SMC". Use the search term "47 Tuc" to center on it. 47 Tucanae (47 Tuc) is a giant globular star cluster. There's information about it in Stellarium, click here for a link to Wikipedia , and you can also Google the term and find out more. 13. Which is farther away from us, the cluster 47 Tuc or the small SMC galaxy? (Hint: Search the web for information about both of these.) Set the date and time to June 15.

If you have chosen a location about 30 to 40 degrees south of the equator from your own longitude, then the time at this site will be the same as your local time. Try 10 PM to get the sky a couple of hours after sunset. High in this southern hemisphere sky you will now see a distinctive pattern of bright stars that outlines the "Southern Cross". It will be above the south celestial pole, while the Magellanic Clouds at this time will be below the pole. You can identify this pattern easily with the constellation outlines (C) and names (V) on. Look for "Crux". 14. Find the names of two bright stars in Crux. Just east of Crux at this time of night is the constellation Centaurus. Look for the bright star Rigel Kentaurus. This star goes by another name, because it is brightest star in Centaurus. It's also one of the closest stars to our Sun. 15. What is the other name for this star? How far is it from the Sun?

Constellations seen from the Northern Hemisphere by Season Summer Cygnus (Deneb in the Northern Cross) Draco Sagittarius (Center of Milky Way) Scorpius (Antares) Rigel: Orion's Brightest Star Rigel: Orion's Brightest Star By Elizabeth Howell, Space.com Contributor | September 19, 2013 06:16pm ET MORE Light from the star Rigel reflects off the dust composing the Witch Head Nebula. Credit: Rogelio Bernal Andreo / NASA Rigel is a blue supergiant that is the brightest star in the constellation Orion (the Hunter). The star is only 10 million years old, compared to the sun's 4.5 billion, and due to its measured size and brightness it is expected to end in a supernova one day. It also has two known companions, Rigel B and Rigel C. The star is variable and is considered an Alpha Cygni-type star.

(Alpha Cygni is the scientific name for Deneb, the prototype star for this kind of variability.) Its luminosity is so bright that it shines and scatters in an adjacent nebula, called the Witch Head Nebula,which is about 40 Earth-sun distances or astronomical units away. In science fiction, Rigel's name is on a a number of planets in the Star Trek universe, is mentioned in The Hitchhiker's Guide to the Galaxy, and also features in a number of novels, computer games and comic books. Rigel before modern astronomy Rigel's name comes from an Arabic phrase, Rijl Jauzah al Yusrāʽ. It means "the left leg of the Jauzah," according to Richard Hinckley Allen's "Star Names: Their Lore and Meaning." It is also sometimes translated as "the left leg of the giant," reportedly referring to the constellation Orion , of which Rigel forms a part. Rigel is more properly known as Beta Orionis. Scandinavian folklore said that Rigel indicated one of the large toes of Orwandil; the thunder god Thor broke off the other toe when it was frost-bitten, according to a report recorded by Allen.

In Japanese culture, Rigel is sometimes called Genji Boshi and a bright red star in Orion — Betelgeuse — has the name of Heike Boshi. Those names hearken back to the Heian era (794-1192) in Japan, according to an online account by Steve Renshaw and Saori Ihara . (A later version of the account was published in the "Kyoto Journal" in 2000.) "The legendary war that brought the somewhat artistic and gentle Heian era to a close took place between the Taira (Heike) and Minamoto (Genji) families," the authors wrote. "The colors of Taira were red, and the colors of the Minamoto family were white. Ultimately, the Minamoto (Rigel) family won the war and moved the capital to Kamakura, ushering in an era of Samurai warriors and leading to centuries of little true peace ... These two bright stars of red and white still do battle with the steepes of the belt holding them apart." Though they look serene and silent from our vantage on Earth, stars are actually roiling balls of violent plasma. Test your stellar smarts with this quiz.

0 of 10 questions complete Star Quiz: Test Your Stellar Smarts Though they look serene and silent from our vantage on Earth, stars are actually roiling balls of violent plasma. Test your stellar smarts with this quiz. 0 of Start Over | More Quizzes Locating Rigel Rigel is today known as a class B supergiant. It's close to zero magnitude in Earth's sky, making it a bright star . But Rigel is also intrinsically luminous, shining with the equivalent light of 85,000 suns, according to astronomer Jim Kaler . Its radius is 73 times that of the sun. Rigel's location is: Right ascension: 5 hours 14 minute 32.3 seconds Declination: -8 degrees 12 minutes 6 seconds Rigel to astronomers Astronomers believe the star is about 10 million years old and that later in its life, it will likely transform into a red supergiant (just like Betelgeuse) and eventually explode into a supernova, Kaler added. "If and when it does go, it would appear to us as bright as a quarter moon," Kaler wrote.

Rigel also has two distant stellar companions, Rigel B and Rigel C – a binary system. At the ninth magnitude, the combined light of these stars would usually be enough for most telescopes to pick up, but they are too close to the bright Rigel to be easily visible. Rigel's bright starlight also bounces off a nebula some 40 light-years away, as shown in a picture published in 2012 on NASA's Astronomy Picture of the Day website . "The blue color of the Witch Head Nebula and of the dust surrounding Rigel is caused not only by Rigel's intense blue starlight, but because the dust grains scatter blue light more efficiently than red," NASA wrote. "The same physical process causes Earth's daytime sky to appear blue, although the scatterers in Earth's atmosphere are molecules of nitrogen and oxygen." Rigel in science fiction The name "Rigel" is a popular planetary name in "Star Trek," with references to it popping up in multiple versions of the series. The earliest mention of it was in the original 1960s-era pilot, "The Cage", which referred to Rigel VII.

Although that episode did not actually air until the 1980s, Rigel VII and much of the footage from 'The Cage" was used in the two-part episode, "The Menagerie." A few other uses of Rigel: In Douglas Adams' "The Hitchhiker's Guide to the Galaxy," Rigel (presumably it is Rigel, as the name "Orion Beta" is used) was the site of madranite mining belts. Several computer games of the 1980s and 1990s, such as "Rescue at Rigel,""Rigel's Revenge" and"Duke Nukem II." A Season 2 episode of "The Simpsons," "Hungry Are the Damned", where the family is temporarily kidnapped by a couple of aliens from Rigel IV. In comic book series such as "Justice League," "Thor," "Transformers" and "Monty." Author Bio Elizabeth Howell, Space.com Contributor Elizabeth Howell is a contributing writer for Space.com who is one of the few Canadian journalists to report regularly on space exploration. She is pursuing a Ph.D. part-time in aerospace sciences (University of North Dakota) after completing an M.Sc.

(space studies) at the same institution. She also holds a bachelor of journalism degree from Carleton University. Besides writing, Elizabeth teaches communications at the university and community college level. To see her latest projects, follow Elizabeth on Twitter at @HowellSpace . Elizabeth Howell, Space.com Contributor on Latest on Rigel: Orion's Brightest Star Rigel in Orion is blue-white | Brightest Stars | EarthSky Rigel in Orion is blue-white By Larry Sessions in Brightest Stars | January 7, 2017 Blue-white Rigel, in the constellation Orion, is one of the brightest stars in the night sky. It’s about twice as hot, and 40,000 times brighter, than our sun. Image via Fred Espenak/astropixels.com The beautiful blue-white star Rigel is in the constellation Orion the Hunter. This constellation is one of the easiest-to-spot of all star patterns, and Rigel is one of the brightest stars in the night sky. Follow the links below to learn more about the star Rigel. Rigel in history and mythology. Rigel in Orion How to see star Rigel in constellation Orion.

The star Rigel is easy to spot, in part because it’s so bright and also because of its distinctive blue-white color. Plus this star graces a lower corner of one of the sky’s most distinctive constellations, Orion the Hunter. You can catch Orion in the east before dawn in late summer, but on January evenings Orion is riding at its highest in the mid-evening sky. Look for Orion high in the south on these Northern Hemisphere winter evenings. By early March, Orion – with blue-white Rigel in its midst – is high in the south as soon as the sun sets. By early May, it is setting before the sky has a chance to get really dark. To find Rigel, look first for its constellation Orion. You’ll look first for three stars in a short, straight line. These stars mark Orion’s Belt. A line drawn downward at a right or 90-degree angle from Orion’s Belt takes you to Rigel. For comparison, draw the line upward and you come to Betelgeuse , with a distinctive orangish tinge. Do not confuse Rigel with Sirius , which is farther to the east and farther south. Sirius is similar in appearance, but significantly brighter than Rigel.

Blue-white Rigel via Clark Planetarium Science of star Rigel. We could not live as close to Rigel as we do to our sun, because its surface temperature is much hotter, about 19,000 degrees F (11,000K) in contrast to about 10,000 degrees F for the sun. Overall, Rigel about 40,000 times brighter than our local star. Earth would need to be about 200 times farther away, or about 5 times as far as Pluto, to bear life in orbit around Rigel. Even then the light would not be the same, as much would be at higher, bluer, wavelengths. Counting all its radiation (not just visible light, but infrared, ultraviolet and so on), Rigel is 66,000 times more powerful than the sun. With such enormous energy, you might be surprised to find that it has only 17 times more mass, and 70 times the width, of our sun. Yet Rigel is not one of the galaxy’s largest stars, as the great video above, by Jon S. on YouTube , shows.

At magnitude 0.18, Rigel is the seventh brightest star in the heavens, the fifth as viewed from North America. It is a blue supergiant star, designated as type B8Ia, some 773 light-years from Earth (by Hipparcos data). In other words, the light you may see from Rigel some spring or winter night, started on its journey a least 250 years before Columbus stumbled upon the outskirts of the already populated North America in his failed attempt to sail to the Orient. Star atlases depict Rigel as the left foot of Orion the Hunter. Via the National Radio Astronomy Observatory Rigel in history and mythology. Historically, the brightest star in a constellation receives the designation Alpha, the second-brightest is Beta, and so on. This system isn’t used for Orion’s star, however. Instead, the red star Betelgeuse is Alpha Orionis, and Rigel is Beta. But Rigel is the brighter star. Go figure. This deviation from standard stellar designations might be because Betelgeuse is a variable star and has been known to at least approach Rigel in brilliance.

Rigel received the designation Beta Orionis from the German astronomer Johann Bayer in the early 1600s, who sought to systematize the naming conventions. It’s possible Betelgeuse actually was brighter around this time. Nowadays, Rigel outshines Betelgeuse, though. By the way, Rigel is also intrinsically brighter than Betelgeuse. If you were to put Rigel and Betelgeuse together at the same distance, Rigel would outshine mighty Betelgeuse by more than 400 percent. The name Rigel comes from an Arabic phrase frequently translated as The Left Foot of the Central One. Although Orion was depicted as a giant or warrior in many cultures, in the original Arabic it might have been reference to a black sheep with a white spot or spots. Thus in the original form, Rigel might have designated the left foot of a sheep! Now, however, many people know it as the left foot of Orion the Hunter. The mythology related to Rigel is sparse and unclear. Perhaps the most interesting connection is in Norse mythology, which sometimes identified Orion with Orwandil (also Orvandil, Aurvandil, Earendel and others).

According to some, Orwandil was traveling with his companion, the god Thor, when his big toe froze in an unfortunate river-crossing incident. Thor broke off the frozen digit and threw it into the sky, where it became the star we see as Rigel. In some variations, the Orwandil’s other big toe became the faint Alcor in Ursa Major. Rigel’s position is RA: 05h 14m 32.3s, dec: -08° 12′ 05.9″.

Question: Rigel and Betelgeuse are two stars in which constellation?
Answer: ORION