Messier 13

Messier 13 or M13, also designated NGC 6205 and sometimes called the Great Globular Cluster in Hercules or the Hercules Globular Cluster, is a globular cluster of several hundred thousand stars in the constellation of Hercules.

Messier 13
Heart of M13 Hercules Globular Cluster
The heart of Hercules Globular Cluster
Credit: ESA/Hubble and NASA
Observation data (J2000 epoch)
ClassV[1]
ConstellationHercules
Right ascension 16h 41m 41.24s[2]
Declination+36° 27′ 35.5″[2]
Distance22.2 kly (6.8 kpc)[3]
Apparent magnitude (V)+5.8[4]
Apparent dimensions (V)20 arcmins
Physical characteristics
Absolute magnitude-8.5
Mass6×105[5] M
Radius84 ly[6]
Metallicity = –1.33[7] dex
Estimated age11.65 Gyr[7]
Notable featuresone of the best-known clusters of the northern hemisphere
Other designationsNGC 6205[4]

Discovery and visibility

M13 was discovered by Edmond Halley in 1714, and cataloged by Charles Messier on June 1, 1764 into his list of objects not to mistake for comets; Messier's list, including Messier 13, eventually became known as the Messier Catalog.[8]

About 1/3 of the way from Vega to Arcturus, four bright stars in the constellation of Hercules form the Keystone asterism. M13 can be seen partway between Zeta Herculis and Eta Herculis. Although only telescopes with great light-gathering capability fully resolve the stars of the Cluster, M13 can be visible to the naked eye depending on circumstances. With a low-power telescope, Messier 13 looks like a comet or fuzzy patch. The cluster is visible throughout the year from latitudes greater than 36 degrees north, with the longest visibility during northern hemisphere spring and summer.[9]

It is located at right ascension 16h 41.7m, declination +36° 28'. With an apparent magnitude of 5.8, it is barely visible with the naked eye on clear nights. Its diameter is about 23 arc minutes and it is readily viewable in small telescopes.[10] Nearby is NGC 6207, a 12th magnitude edge-on galaxy that lies 28 arc minutes directly northeast. A small galaxy, IC 4617, lies halfway between NGC 6207 and M13, north-northeast of the large globular cluster's center.

Traditional binoculars make the Hercules Globular Cluster look similar to a round patch of light. At least four inches of telescope aperture will allow observing the stars that constitute M13 as small pinpoints of light. However, only larger telescopes allow resolving stars further into the center of the cluster.[11]

Characteristics

M13 is about 145 light-years in diameter, and it is composed of several hundred thousand stars, the brightest of which is a red giant, the variable star V11, with an apparent visual magnitude of 11.95. M13 is about 22,200 light-years away from Earth.

It wasn't until 1779 that the single stars in this globular cluster were resolved. Compared to the stars in the neighborhood of the Sun, the stars in M13's stellar population are more than a hundred times denser. They are so densely packed together that they sometimes collide and produce new stars. The newly-formed, young stars, so-called "blue stragglers," are particularly interesting to astronomers.[12]

The Arecibo message of 1974, which contained encoded information about the human race, DNA, atomic numbers, Earth's position and other information, was beamed from the Arecibo Observatory radio telescope towards M13 as an experiment in contacting potential extraterrestrial civilizations in the cluster. The cluster will move through space during the transit time; opinions differ as to whether or not the cluster will be in a position to receive the message by the time it arrives.[13] [14]

Literary references

Gallery

Hercules constellation map

M13 is in "armpit" of Hercules constellation

Messier 13 Wide Field

Wide field image of Messier 13

M13 from an 8" SCT

M13 from an 8" SCT in San Diego, California

See also

References

  1. ^ Shapley, Harlow; Sawyer, Helen B. (August 1927), "A Classification of Globular Clusters", Harvard College Observatory Bulletin, 849 (849): 11–14, Bibcode:1927BHarO.849...11S.
  2. ^ a b Goldsbury, Ryan; et al. (December 2010), "The ACS Survey of Galactic Globular Clusters. X. New Determinations of Centers for 65 Clusters", The Astronomical Journal, 140 (6): 1830–1837, arXiv:1008.2755, Bibcode:2010AJ....140.1830G, doi:10.1088/0004-6256/140/6/1830.
  3. ^ Paust, Nathaniel E. Q.; et al. (February 2010), "The ACS Survey of Galactic Globular Clusters. VIII. Effects of Environment on Globular Cluster Global Mass Functions", The Astronomical Journal, 139 (2): 476–491, Bibcode:2010AJ....139..476P, doi:10.1088/0004-6256/139/2/476.
  4. ^ a b "M 13". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2006-11-15.
  5. ^ Leonard, Peter J. T.; Richer, Harvey B.; Fahlman, Gregory G. (1992), "The mass and stellar content of the globular cluster M13", Astronomical Journal, 104: 2104, Bibcode:1992AJ....104.2104L, doi:10.1086/116386.
  6. ^ distance × sin( diameter_angle / 2 ) = 84 ly radius
  7. ^ a b Forbes, Duncan A.; Bridges, Terry (May 2010), "Accreted versus in situ Milky Way globular clusters", Monthly Notices of the Royal Astronomical Society, 404 (3): 1203–1214, arXiv:1001.4289, Bibcode:2010MNRAS.404.1203F, doi:10.1111/j.1365-2966.2010.16373.x.
  8. ^ "Messier 13 (M13) - The Great Hercules Cluster - Universe Today". Universe Today. 2016-05-09. Retrieved 2018-04-23.
  9. ^ "M13: Great Cluster in Hercules | EarthSky.org". earthsky.org. Retrieved 2018-03-26.
  10. ^ "M 13". Messier Objects Mobile -- Charts, Maps & Photos. 2016-10-16. Retrieved 2018-04-23.
  11. ^ "How to See the Great Hercules Cluster of Stars". Space.com. Retrieved 2018-04-23.
  12. ^ Garner, Rob (2017-10-06). "Messier 13 (The Hercules Cluster)". NASA. Retrieved 2018-04-23.
  13. ^ "It's the 25th anniversary of Earth's first attempt to phone E.T." 1999-11-12. Retrieved 2018-06-28.
  14. ^ "Science 2.0". In regard to the email from. Retrieved 2015-04-15.

External links

Coordinates: Sky map 16h 41m 41.44s, 36° 27′ 36.9″

1974 in science

The year 1974 in science and technology involved some significant events, listed below.

1994 National Hockey League All-Star Game

The 1994 National Hockey League All-Star Game was held in Madison Square Garden in New York City, home of the New York Rangers, on January 22, 1994.

Courtney Reum

Courtney Reum is an American entrepreneur, product developer and the co-founder of the Los Angeles based investment firm M13. He was a former investment banker at Goldman Sachs who worked with companies including Under Armor, Vitaminwater and Procter & Gamble . At Goldman Sachs he worked on the merger of Allied Domecq and Pernod Ricard, an experience that led to the creation of his own alcohol company, VeeV, which he launched in late 2007 with his brother, M13 co-owner, Carter Reum . VeeV became a national best selling brand available in bars, restaurants, national chains and retailers like Walmart, Target and Kroger stores. VeeV is also available on Virgin America flights and hotel chains like Hyatt and Marriott.

Frozen Fury

Frozen Fury was an annual pre-season ice hockey game between the Los Angeles Kings and the Colorado Avalanche of the National Hockey League (NHL), held in Las Vegas, Nevada from 1997 to 2016. On three occasions, the Los Angeles Kings faced different teams instead of the Avalanche, once each against the Arizona Coyotes, the San Jose Sharks, and the New York Rangers. The 15th Frozen Fury was originally supposed to take place on September 29, 2012, but was cancelled due to the NHL lockout. It resumed September 27–28, 2013, with the New York Rangers making their debut in the series.

The first game to be played in Las Vegas was also the first outdoor game in the league's history: 14,000 fans came to a rink set up outside Caesars Palace to see the Kings defeat the New York Rangers 5–2 on September 28, 1991. The air temperature was 85 °F (29 °C) during the game. The game served as a predecessor to both the Frozen Fury series (which was played indoors) and the NHL Winter Classic, the annual regular season game held on New Year's Day that began in 2008.

From 1997 to 2015, these games were played at MGM Grand Garden Arena; in 2016, they were played at T-Mobile Arena. The 2016 games were the end of the tradition, because of the launch of the Vegas Golden Knights in the 2017–18 season.

Hans Ludendorff

Friedrich Wilhelm Hans Ludendorff (Dunowo, 26 May 1873 - Potsdam, 26 June 1941) was a German astronomer and astrophysicist. He was the younger brother of General Erich Ludendorff.

After studying Physics, Mathematics and Astronomy in Berlin, he started to work as assistant at the Hamburg observatory in 1897. The following year he changed to the Astrophysical Observatory of Potsdam, where became Observator (1905) and Chief Observator (1915). From 1921 until his retirement in 1938 he was Director of the Observatory. Between 1920 and 1930 he belonged to the Board of the Astronomical Society.

He authored several astronomical and astrophysical works (the first was about asteroids, following his graduation in 1896), but is better known for the Ludendorff Catalogue, that lists the most important stars in the globular cluster Messier 13, published in 1905.

In 1908 he established the binary character of the star Mizar B (period: 175.6 days), together with American astronomer Edwin Brant Frost.

He also authored several studies on the astronomy of Pre-Columbian civilizations, especially that of the Mayas.

List of Stanley Cup champions

The Stanley Cup is a trophy awarded annually to the playoff champion club of the National Hockey League (NHL) ice hockey league. It was donated by the Governor General of Canada Lord Stanley of Preston in 1892, and is the oldest professional sports trophy in North America. Inscribed the Dominion Hockey Challenge Cup, the trophy was first awarded to Canada's amateur ice hockey clubs who won the trophy as the result of challenge games and league play. Professional clubs came to dominate the competition in the early years of the twentieth century, and in 1913 the two major professional ice hockey organizations, the National Hockey Association (NHA) (forerunner of the NHL) and the Pacific Coast Hockey Association (PCHA), reached a gentlemen's agreement in which their respective champions would face each other in an annual series for the Stanley Cup. After a series of league mergers and folds, it became the de facto championship trophy of the NHL in 1926, though it was nominally still subject to external challenge. After 1947, the Cup became the de jure NHL championship prize.

From 1914 to the end of the 2018 season, the trophy has been won 100 times. 24 teams have won the cup, 19 of which are still active in the NHL. Prior to that, the challenge cup was held by nine teams. The Montreal Canadiens have won the Stanley Cup 24 times and made the finals an additional ten times. There were two years when the Stanley Cup was not awarded: 1919, because of the Spanish flu epidemic, and 2005, because of the NHL lockout.

List of interstellar radio messages

This is a list of interstellar radio messages.

Messier 3

Messier 3 (M3 or NGC 5272) is a globular cluster of stars in the northern constellation of Canes Venatici. It was discovered on May 3, 1764, and was the first Messier object to be discovered by Charles Messier himself. Messier originally mistook the object for a nebula without stars. This mistake was corrected after the stars were resolved by William Herschel around 1784. Since then, it has become one of the best-studied globular clusters. Identification of the cluster's unusually large variable star population was begun in 1913 by American astronomer Solon Irving Bailey and new variable members continue to be identified up through 2004.Many amateur astronomers consider it one of the finest northern globular clusters, following only Messier 13. M3 has an apparent magnitude of 6.2, making it a difficult naked eye target even with dark conditions. With a moderate-sized telescope, the cluster is fully defined. It can be a challenge to locate through the technique of star hopping, but can be found by looking almost exactly halfway along an imaginary line connecting the bright star Arcturus to Cor Caroli. Using a telescope with a 25 cm (9.8 in) aperture, the cluster has a bright core with a diameter of about 6 arcminutes and spans a total of 12 arcminutes.This cluster is one of the largest and brightest, and is made up of around 500,000 stars. It is estimated to be 8 billion years old. It is located at a distance of about 33,900 light-years away from Earth.Messier 3 is located 31.6 kly (9.7 kpc) above the Galactic plane and roughly 38.8 kly (11.9 kpc) from the center of the Milky Way. It contains 274 known variable stars; by far the highest number found in any globular cluster. These include 133 RR Lyrae variables, of which about a third display the Blazhko effect of long-period modulation. The overall abundance of elements other than hydrogen and helium, what astronomers term the metallicity, is in the range of –1.34 to –1.50 dex. This value gives the logarithm of the abundance relative to the Sun; the actual proportion is 3.2–4.6% of the solar abundance. Messier 3 is the prototype for the Oosterhoff type I cluster, which is considered "metal-rich". That is, for a globular cluster, Messier 3 has a relatively high abundance of heavier elements.

Messier 92

Messier 92 (also known as M92, M 92, or NGC 6341) is a globular cluster of stars in the northern constellation of Hercules. It was discovered by Johann Elert Bode in 1777, then published in the Jahrbuch during 1779. The cluster was independently rediscovered by Charles Messier on March 18, 1781 and added as the 92nd entry in his catalogue. M92 is at a distance of about 26,700 light-years away from Earth.

M92 is one of the brighter globular clusters in the northern hemisphere, but it is often overlooked by amateur astronomers because of its proximity to the even more spectacular Messier 13. It is visible to the naked eye under very good conditions.Among the Milky Way population of globular clusters, Messier 92 is among the brighter clusters in terms of absolute magnitude. It is also one of the oldest clusters. Messier 92 is located around 16×10^3 ly (4.9 kpc) above the galactic plane and 33×10^3 ly (10 kpc) from the Galactic Center. The heliocentric distance of Messier 92 is 26.7×10^3 ly (8.2 kpc). The half-light radius, or radius containing half of the light emission from the cluster, is 1.09 arcminutes, while the tidal radius is 15.17 arcminutes. It appears only slightly flattened, with the minor axis being about 89% ± 3% as large as the major axis.Characteristic of other globulars, Messier 92 has a very low abundance of elements other than hydrogen and helium; what astronomers term its metallicity. Relative to the Sun, the abundance of iron in the cluster is given by [Fe/H] = –2.29 dex, which equates to only 0.5% of the solar abundance. This puts the estimated age range for the cluster at 14.2 ± 1.2 billion years, or roughly the age of the Universe.The cluster is not currently in a state of core collapse and the core radius is about 2 arcseconds. It is an Oosterhoff type II (OoII) globular cluster, which means it belongs to the group of metal poor clusters with longer period RR Lyrae variable stars. The 1997 Catalogue of Variable Stars in Globular Clusters listed 28 candidate variable stars in the cluster, although only 20 have been confirmed. As of 2001, there are 17 known RR Lyrae variables in Messier 92. 10 X-ray sources have been detected within the 1.02 arcminute half-mass radius of the cluster, of which half are candidate cataclysmic variable stars.

NGC 6207

NGC 6207 is a spiral galaxy located in the constellation Hercules. It is designated as SA(s)c in the galaxy morphological classification scheme and was discovered by William Herschel on 16 May 1787. NGC 6207 is located at about 30 million light years from earth. It is located near the globular cluster Messier 13.

November 16

November 16 is the 320th day of the year (321st in leap years) in the Gregorian calendar. 45 days remain until the end of the year.

Perry Rhodan

Perry Rhodan is the eponymous hero of a German science fiction novel series which has been published each week since 8 September 1961 in the 'Romanhefte' format (digest-sized booklets, usually containing 66 pages, the German equivalent of the now-defunct American pulp magazine) by Pabel-Moewig Verlag, a subsidiary of Bauer Media Group. As of February 2019, 3000 booklet novels of the original series plus 850 spinoff novels of the sister series Atlan plus over 400 paperbacks and 200 hardcovers have been published, totalling over 300,000 pages. Having sold approximately two billion copies (in novella format) worldwide alone, (including over one billion in Germany), it is the most successful science fiction book series ever written. The first billion of worldwide sales was celebrated in 1986.The first 126 novels (plus five novels of the spinoff series Atlan) were translated into English and published by Ace Books between 1969 and 1978, with the same translations used for the British edition published by Futura Publications which issued only 39 novels. When Ace cancelled its translation of the series, translator Wendayne Ackerman self-published the following 19 novels (under the business name 'Master Publications') and made them available by subscription only. Financial disputes with the German publishers led to the cancellation of the American translation in 1979.

An attempt to revive the series in English was made in 1997–1998 by Vector Publications of the US which published translations of four issues (1800–1803) from the current storyline being published in Germany at the time.

The series and its spin-offs have captured a substantial fraction of the original German science fiction output and exert influence on many German writers in the field. The series is told in an arc storyline structure. An arc—called a "cycle"—would have anywhere from 25 to 100 issues devoted to it, similar subsequent cycles are referred to as a "grand-cycle".Matthias Rust, the then-19 year old aviator who landed his Cessna 172 aircraft on the Red Square in Moscow in 1987, has cited Perry Rhodan's adventures as his main inspiration to penetrate Soviet airspace.

Question and Answer (novel)

Question and Answer is a science fiction novel by American writer Poul Anderson. It originally appeared in the June and July 1954 issues of magazine Astounding Science Fiction, and was later reprinted in 1956 as part of Ace Double D-199 under the title Planet of No Return, and again as a stand-alone Ace novel in February 1978 under the original title.

Star cluster

Star clusters are very large groups of stars. Two types of star clusters can be distinguished: globular clusters are tight groups of hundreds to millions of old stars which are gravitationally bound, while open clusters, more loosely clustered groups of stars, generally contain fewer than a few hundred members, and are often very young. Open clusters become disrupted over time by the gravitational influence of giant molecular clouds as they move through the galaxy, but cluster members will continue to move in broadly the same direction through space even though they are no longer gravitationally bound; they are then known as a stellar association, sometimes also referred to as a moving group.

Star clusters visible to the naked eye include the Pleiades (M45), Hyades, and the Beehive Cluster (M44).

Star hopping

Star hopping is a technique that amateur astronomers often use to locate astronomical objects in the night sky. It can be used instead of or in addition to setting circles.

Sucker Bait

"Sucker Bait" is a science fiction novella by American writer Isaac Asimov. It was first serialized in the February and March 1954 issues of Astounding Science Fiction, and reprinted in the 1955 collection The Martian Way and Other Stories. It has also been adapted as an episode of the BBC anthology television series Out of the Unknown.

The War in Space

The War in Space, released in Japan as Great Planet War: The War in Space (惑星大戦争 The War in Space, Wakusei Daisensō: Za uō in Supēsu"), is a tokusatsu science fiction film produced and released by Toho Studios in 1977.

The Wheel in Space

The Wheel in Space is the mostly missing seventh and final serial of the fifth season in the British science fiction television series Doctor Who, which originally aired in six weekly parts from 27 April to 1 June 1968. This serial is the first appearance of Wendy Padbury as companion Zoe Heriot. Only two of the six episodes are held in the BBC archives; four still remain missing.

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See also

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