Betelgeuse ( α Orion , α Ori ) is a bright star in the constellation Orion . A red supergiant , a semi-regular variable star , the brightness of which varies from 0.2 to 1.2 magnitudes and averages about 0.7 m . The red color of the star, easily noticeable when observed with the naked eye, corresponds to a color index of BV = 1.86 m . The minimum luminosity of Betelgeuse is greater than the luminosity of the Sun by 80 thousand times, and the maximum is 105 thousand times [4] . Determining the exact distance to Betelgeuse is complicated by the fact that its annual parallax is much smaller than the angular diameter of the star’s disk. According to 2017 estimates, the distance to the star is 222 parsecs with an accuracy of -34 / + 48 parsecs (approximately from 613 to 881 light years ) [5] . The Betelgeuse angular diameter , according to the 2017 estimate, is about 0.044 arc seconds [5] . This is one of the largest stars known to astronomers: if it was placed in the place of the Sun, then at the minimum expected size it would fill the orbit of Mars , and at the maximum it would reach the orbit of Jupiter .
Betelgeuse | |||
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Star | |||
Betelgeuse in the constellation Orion | |||
Observational data ( Age J2000.0 ) | |||
Right ascension | |||
Declination | |||
Distance | ≈ 724 ± 133 St. years (≈ 222 pc ) | ||
Visible magnitude ( V ) | from +0.2 to +1.2 | ||
Constellation | Orion | ||
Astrometry | |||
Radial velocity ( R v ) | +22.0 km / s | ||
Own movement (μ) | RA: 27.33 mas per year Dec: 10.86 mas per year | ||
Parallax (π) | 5.07 ± 1.64 mas | ||
Absolute magnitude (V) | −5.14 | ||
Specifications | |||
Spectral class | M2Iab | ||
Color Index ( B - V ) | 1.86 | ||
Color Index ( U - B ) | 2.06 | ||
Variability | SRc ( semi-correct ) | ||
physical characteristics | |||
Weight | 1,531E31 kg, 13-17 [1] [2] M ☉ | ||
Radius | 950—1200 [3] R ☉ | ||
Age | 1⋅10 7 years | ||
Temperature | 3600 K | ||
Luminosity | 40 000-100 000 (bolometric) L ☉ | ||
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Database Information | |||
SIMBAD | data | ||
The Betelgeuse mass is approximately 17 solar masses [1] .
Content
Name Origin
The generally accepted [4] version is that the name is a distortion of the Arab. يد الجوزاء (Yad al-Jawza, "the hand of Gemini", more precisely, the central or conjugated epithet, which meant the constellations of Gemini and Orion ). The name Betelgeuse (Beteljouz) is also translated as the house of the twins , but this option is based on a mistake. In Arab astronomy, Orion was sometimes called Gemini; this name should not be confused with the modern constellation Gemini. In the Middle Ages, the first letter of the Arabic name ( يـ , with two dots - “th”) was not read correctly ( بـ , with one dot - “b”), and the name was transliterated into lat. Bedalgeuze . Later, during the Renaissance , they began to believe that the name was originally written as "Beit al-Jawza", which, apparently, should mean the twin armpit in Arabic. This led to a modern sound, but in fact the Arab could have led to such a translation . ابط ([ibt], “armpit”) [6] . And in 1963, Richard Hinckley Allen mistakenly re-wrote the original name as Ibţ al Jauzah [7] .
This star has other names:
- "Ad-Dira" ("hand"),
- Al-Manqib (“shoulder”),
- Al-Yad al-Yamna (“right hand”),
- Ardra ( Hindi )
- Bahu ( Sanskrit, “hand”),
- "Tower" ( Persian , "hand"),
- Gula (in the Euphrates Valley),
- “Claria” ( Coptic language , “dressing”).
Key Features
Some features of Betelgeuse are of considerable interest to astronomers. This is one of the first stars for which the angular diameter visible from the Earth was measured using an astronomical interferometer : according to the measurements of Michelson and Pisa (December 13, 1920), the Betelgeuse angular diameter is 0.047 " [8] . Subsequently, it was found to change. The distance to Betelgeuse is unknown with sufficient accuracy, but if it is assumed to be 650 light years , then the diameter of the star during its pulsations varies from 500 to 800 diameters of the Sun.
The exact Betelgeuse diameter is not easy to determine, since its brightness gradually decreases with distance from the center of the disk; the color of the radiation also changes depending on this distance. Although Betelgeuse is only 17 times heavier than the Sun, its volume is more than 300 million times. Betelgeuse became the first star after the Sun, for which images of the disk and spots on it were obtained. They were discovered on images obtained by telescopes operating in the aperture-diaphragm interferometry mode , and were later seen on more detailed images obtained on the COAST telescope [9] .
The Betelgeuse rotational speed around its axis is about 15 km / s, which is significantly higher than the rotational speed typical of red supergiants. According to the assumption of a group of astronomers led by J. Craig Wheeler from the University of Texas at Austin , USA, this is explained by the fact that Betelgeuse absorbed a star circulating around it with a mass approximately equal to the mass of the Sun [12] [13] .
It is noteworthy that during the observation period from 1993 to 2009, the diameter of the star decreased by 15%, from 5.5 to about 4.7, and by 2011 - to 4.5 astronomical units , and astronomers can not yet explain with what is the reason [14] [15] . Moreover, the brightness of the star has not changed any noticeably during this time [16] [17] .
The reasons for the observed decrease in the Betelgeuse radius can also be associated with an incorrect interpretation of the data obtained, for example:
- differences in brightness of different parts of the star’s surface; due to rotation, these inhomogeneities change position, as a result of which the visible gloss changes. These changes can be taken as changes in diameter.
- Modeling supergiant stars suggests that such stars may be nonspherical, similar to irregularly shaped potatoes. It is assumed that Betelgeuse can have a rotation period of 18 years, that is, while Betelgeuse was observed by orbital telescopes for less than one revolution around its axis [18] .
- It is possible that scientists do not observe the true diameter of the star, but a certain layer of dense molecular gas, the movements of which create the appearance of a change in the true size of the star.
Nobel laureate Charles Townes said he plans to continue monitoring Betelgeuse in the hope of finding some kind of systematic change in diameter and understand their cause. To improve the possibilities of observation, he plans to use a special spectrometer for the interferometer [19] . [ significance of fact? ]
Around the star there is a gas nebula, which for a long time could not be seen due to the fact that it is overshadowed by the light of the star [14] .
The future of the star
The most likely scenario for the end of the evolution of a star is that Betelgeuse will ultimately undergo a Type II supernova explosion , although it is possible that the star will not explode and throw off shells in the form of a planetary nebula , and a white dwarf of a rare oxygen - neon type will remain. When a star burst occurs, none of the scientists probably knows - this can happen with the same probability both tomorrow and after a thousand years [20] .
Everyone agrees that such a supernova explosion will be a grandiose astronomical event, but, being very distant from the Earth, it will not pose a significant threat to life on it [20] .
In the event of an explosion, Betelgeuse can increase its brightness by at least 10 thousand times, shining with the brightness of a crescent. The maximum brightness is −9 m . For comparison: the full moon has a brightness of −12 m [20] . The explosion will last for several months; the star will be easily visible during the day and looks like a shining dot of the color of red-hot glass. After the explosion, the luminosity of the star will gradually decrease and within a few months or years it will cease to be visible to the naked eye. Orion's right shoulder will disappear for some time, and after a few centuries a nebula will appear in its place.
However, if the rotation axis of Betelgeuse is directed to the Earth, there will be more tangible effects. A stream of gamma rays and other cosmic particles will be directed to Earth. Strong auroras and possibly a noticeable increase in the number of cosmic particles reaching the Earth’s surface will be observed, with subsequent adverse effects on life on the planet. In the case of this orientation with respect to the solar system, the flash will also be many times brighter than if the axis of the star is directed away from us [21] .
See also
- List of the biggest stars
- List of the brightest stars
- Egyptian Cross (Asterism)
Notes
- ↑ 1 2 New photos revealed giant bubbles on Betelgeuse . Lenta.ru (July 30, 2009). Date of treatment August 13, 2010. Archived August 24, 2011.
- ↑ Astronomers have determined the Betelgeuse mass (Inaccessible link) . Archived on September 24, 2011.
- ↑ Mohamed, S .; Mackey, J .; Langer, N. 3D Simulations of Betelgeuse's Bow Shock (Eng.) // Astronomy and Astrophysics . - EDP Sciences 2012. - Vol. 541, id.A1 . - P. A1 . - DOI : 10.1051 / 0004-6361 / 201118002 . - . - arXiv : 1109.1555v2.pdf .
- ↑ 1 2 Jim Kaler. Betelgeuse (Alpha Orionis) (inaccessible link) . Archived December 16, 2008.
- ↑ 1 2 https://limo.libis.be/primo-explore/fulldisplay?docid=LIRIAS1764834&context=L&vid=Lirias&search_scope=Lirias&tab=default_tab&lang=en_US&fromSitemap=1
- ↑ Kunitzsch, P .; Smart, T. A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations. - 2nd ed., Rev. and add. - Cambridge, MA: Sky Pub., 2006. - ISBN 9781931559447 .
- ↑ Allen, Richard Hinckley (1963). Star Names: Their Lore and Meaning (Revised edition).
- ↑ AA Michelson, FG Pease. Measurement of the diameter of alpha Orionis with the interferometer. (Eng.) // The Astrophysical Journal . - IOP Publishing , 1921-05-01. - Vol. 53 . - ISSN 0004-637X . - DOI : 10.1086 / 142603 .
- ↑ The surface structure and limb-darkening profile of Betelgeuse
- ↑ E. O'Gorman, P. Kervella, GM Harper, AMS Richards, L. Decin, M. Montargès, and I. McDonald. The inhomogeneous sub-millimeter atmosphere of Betelgeuse // arxiv.org: pdf. - 2017 .-- 19 June.
- ↑ ALMA (ESO / NAOJ / NRAO) / E. O'Gorman / P. Kervella An ALMA image of the Betelgeuse surface (Inaccessible link) . www.eso.org (June 26, 2017). - This orange bubble is the Betelgeuse star next to us, shot by the ALMA telescope (Atacama Large Millimeter / submillimeter Array). These are the first observations of the stellar surface made on ALMA, and at the first attempt a higher resolution is achieved than in all previous Betelgeuse observations. Archived on June 30, 2017.
- ↑ The famous Betelgeuse star could devour a companion star 100,000 years ago - space, astronomy and astronautics news on ASTRONEWS.ru . www.astronews.ru. Date of treatment January 17, 2019.
- ↑ JM Fowler, JM Sullivan, M. Koutoulaki, L. Zhou, J. Hickey. The Betelgeuse Project: constraints from rotation (Eng.) // Monthly Notices of the Royal Astronomical Society . - Oxford University Press , 2017-03-01. - Vol. 465 , iss. 3 . - P. 2654-2661 . - ISSN 0035-8711 . - DOI : 10.1093 / mnras / stw2893 .
- ↑ 1 2 Science News - R & D.CNews Neopr . www.rnd.cnews.ru. Date of treatment July 1, 2017.
- ↑ Computerra: How to bring popular diplomacy back to life? (inaccessible link) . science.compulenta.ru. Date of treatment July 1, 2017. Archived March 30, 2013.
- ↑ Popular Giant Star Shrinks Mysteriously . Space.com . Date of treatment July 1, 2017.
- ↑ Betelgeuse diameter changes over time (inaccessible link) . astronet.ru (June 30, 2009). Archived August 24, 2011.
- ↑ Betelgeuse: The incredible shrinking star? . NewScientist (June 10, 2009). Archived August 24, 2011.
- ↑ CH Townes, EH Wishnow, DDS Hale, B. Walp. A Systematic Change with Time in the Size of Betelgeuse // The Astrophysical Journal . - IOP Publishing 2009-06-01. - Vol. 697 . - P. L127 — L128 . - ISSN 2041-8205 .
- ↑ 1 2 3 Oksana Gribanova. Scientists commented on the news of the appearance of the second Sun // Russian newspaper . - 2016. - May 18.
- ↑ A second sun will appear in the sky . STS.
Literature
- Orion, constellation // Brockhaus and Efron Encyclopedic Dictionary : in 86 volumes (82 volumes and 4 additional). - SPb. , 1890-1907.
Links
- Surface imaging of Betelgeuse with COAST and the WHT (inaccessible link) . Archived on June 14, 2007.
- ALMA received the most detailed image of Betelgeuse In-Space.ru
- Betelgeuse: the clearest shot of AKD on Astronet