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,[9] 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.[10] 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.[11]

Many amateur astronomers consider it one of the finest northern globular clusters, following only Messier 13.[2] M3 has an apparent magnitude of 6.2,[5] 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.[2]

This cluster is one of the largest and brightest, and is made up of around 500,000 stars.[10] 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.[12]

Messier 3
Messier3 - HST - Potw1914a
Hubble image of Messier 3.[1]
Observation data (J2000 epoch)
ConstellationCanes Venatici
Right ascension 13h 42m 11.62s[3]
Declination+28° 22′ 38.2″[3]
Distance33.9 kly (10.4 kpc)[4]
Apparent magnitude (V)+6.2[5]
Apparent dimensions (V)18′.0
Physical characteristics
Absolute magnitude-8.93
Mass4.5×105[6] M
Radius90 ly
Tidal radius113 ly (30 pc)[mean][7]
Metallicity = –1.34[8] dex
Estimated age11.39 Gyr[8]
Other designationsNGC 5272[5]


Messier 3 - Adam Block - Mount Lemmon SkyCenter - University of Arizona

Mount Lemmon SkyCenter image of Messier 3


Arcturus can be used to help locate M3


Messier 3 with amateur telescope


  1. ^ "Blue rejuvenation". Retrieved 8 April 2019.
  2. ^ a b c Thompson, Robert Bruce; Thompson, Barbara Fritchman (2007), Illustrated guide to astronomical wonders, DIY science O'Reilly Series, O'Reilly Media, Inc., p. 137, ISBN 978-0-596-52685-6.
  3. ^ 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.
  4. ^ 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.
  5. ^ a b c "M 3". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2006-11-15.
  6. ^ Marks, Michael; Kroupa, Pavel (August 2010), "Initial conditions for globular clusters and assembly of the old globular cluster population of the Milky Way", Monthly Notices of the Royal Astronomical Society, 406 (3): 2000–2012, arXiv:1004.2255, Bibcode:2010MNRAS.406.2000M, doi:10.1111/j.1365-2966.2010.16813.x. Mass is from MPD on Table 1.
  7. ^ Brosche, P.; Odenkirchen, M.; Geffert, M. (March 1999). "Instantaneous and average tidal radii of globular clusters". New Astronomy. 4 (2): 133–139. Bibcode:1999NewA....4..133B. doi:10.1016/S1384-1076(99)00014-7.
  8. ^ 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.
  9. ^ Machholz, Don (2002), The observing guide to the Messier marathon: a handbook and atlas, Cambridge University Press, ISBN 978-0-521-80386-1.
  10. ^ a b Garner, Rob (2017-10-06). "Messier 3". NASA. Retrieved 2018-04-13.
  11. ^ Valcarce, A. A. R.; Catelan, M. (August 2008), "A semi-empirical study of the mass distribution of horizontal branch stars in M 3 (NGC 5272)", Astronomy and Astrophysics, 487 (1): 185–195, arXiv:0805.3161, Bibcode:2008A&A...487..185V, doi:10.1051/0004-6361:20078231.
  12. ^ Cacciari, C.; Corwin, T. M.; Carney, B. W. (January 2005), "A Multicolor and Fourier Study of RR Lyrae Variables in the Globular Cluster NGC 5272 (M3)", The Astronomical Journal, 129 (1): 267–302, arXiv:astro-ph/0409567, Bibcode:2005AJ....129..267C, doi:10.1086/426325.

External links

Coordinates: Sky map 13h 42m 11.23s, 28° 22′ 31.6″

1979–80 Edmonton Oilers season

The 1979–80 Edmonton Oilers season was the Oilers' eighth season, their first season in the National Hockey League (NHL), as they were one of the teams that were part of the WHA-NHL merger that took place on June 22, 1979.

The Oilers were led offensively by rookie superstar Wayne Gretzky, as he tied for the lead league in points at 137, however lost the Art Ross Trophy due to scoring fewer goals than winner Marcel Dionne. Gretzky, however, would win the Hart Memorial Trophy as MVP of the NHL, but was declared ineligible for the Calder Memorial Trophy due to his playing days in the WHA.

Edmonton played six goaltenders during the season, and was led by Eddie Mio's nine wins, while Ron Low, who came over in a trade with the Quebec Nordiques, would go 8–2–1 in 11 games with the Oilers.

They would make the playoffs, however were quickly swept out by the powerful Philadelphia Flyers in 3 games, but Oilers fans were very excited about being part of the NHL, and of the future of the team.

1984 Stanley Cup playoffs

The 1984 Stanley Cup playoffs, the championship of the National Hockey League (NHL) began on April 4, after the conclusion of the 1983–84 NHL season. The playoffs concluded on May 19 with the Edmonton Oilers defeating the four time defending champion New York Islanders 5–2 to win the Stanley Cup Finals four games to one, the franchise's first Stanley Cup.

1986 Stanley Cup playoffs

The 1986 Stanley Cup playoffs, the championship of the National Hockey League (NHL) began on April 9, after the conclusion of the 1985–86 NHL season. The playoffs concluded on May 24 with the champion Montreal Canadiens defeating the Calgary Flames 4–1 to win the series four games to one and win the Stanley Cup.

This was the last time to date that all active Canadian teams have qualified in the same season. It is also the second time that all seven active teams at the time qualified, the first occurring three years earlier. The playoffs of 1986 saw three first place teams eliminated in the opening round and the fourth, Edmonton, bowed out in the second. This would be the last time that all six Sutter brothers would participate in the playoffs in the same year.

The Montreal Canadiens decided to go with a rookie goaltender by the name of Patrick Roy. This decision proved to be a good one just like when the Canadiens rode rookie goalie Ken Dryden to a Stanley Cup championship in 1971. In the Final, the Canadiens beat the Calgary Flames, who were also riding a rookie netminder, Mike Vernon. Patrick Roy won the Conn Smythe Trophy as the playoff MVP and had a sparkling 1.92 goals against average along with 15 wins. St. Louis forwards Doug Gilmour and Bernie Federko led the playoffs in scoring with 21 points despite missing the finals; this feat was not repeated until 1999.

The 1986 playoffs marked the first time that all four former WHA teams made the playoffs in the same year. This would happen again the following year and in 1999, by which time 3 of those teams had moved, the Quebec Nordiques to Denver, the Winnipeg Jets to Phoenix, and the Hartford Whalers to Raleigh, North Carolina.

1988 Stanley Cup playoffs

The 1988 Stanley Cup playoffs, the championship of the National Hockey League (NHL), began on April 6, after the conclusion of the 1987–88 NHL season. It concluded on May 26, with the defending champion Edmonton Oilers defeating the Boston Bruins to win their second straight Stanley Cup and fourth in five years.

The Presidents' Trophy winning Calgary Flames had home ice advantage during the playoffs thanks in part to Edmonton's struggles without Wayne Gretzky, who missed a number of games due to injury. The Oilers, who had won the Cup in three of the previous four seasons, were still thought to have a good chance at repeating with Gretzky's return. The clash between the Flames and Oilers in the Smythe Division Final was highly anticipated.

The New Jersey Devils made the playoffs for the first time since their move from Denver, winning in overtime at Chicago Stadium on the season's final day to edge the New York Rangers for the Patrick Division's fourth spot. This was only the second time they made the playoffs including their Colorado and Kansas City days.

Gretzky set NHL playoff records with 31 assists in 18 games and 13 points in the Stanley Cup Finals.

1988–89 Minnesota North Stars season

The 1988–89 was the North Stars' 22nd season. It saw the North Stars finish in third place in the Norris Division with a record of 27 wins, 37 losses, and 16 ties for 70 points. They lost the Division Semi-finals in five games to the St. Louis Blues.

1991 Stanley Cup playoffs

The 1991 Stanley Cup Playoffs for the National Hockey League (NHL) championship began on April 3, 1991, following the 1990–91 regular season. The 16 teams that qualified, from the top four teams of the four divisions, played best-of-seven series with re-seeding after the division finals. The Conference Champions played a best-of-seven series for the Stanley Cup.

This was the first of the 25 consecutive years in which the Detroit Red Wings qualified for the Stanley Cup playoffs until their streak finally ended in 2017. Their streak is tied for the third longest in NHL history, and was the longest active playoff appearance streak in the four major American professional sports.

The finals concluded on May 25 with the Pittsburgh Penguins winning the Stanley Cup, defeating the Minnesota North Stars in the final series four games to two. Pittsburgh forward Mario Lemieux was awarded the Conn Smythe Trophy as Most Valuable Player of the playoffs.

This was the first NHL playoffs without any series sweeps since the 1972–73 season. In addition, this season set the record for most playoff games played with 92, which stood until 2014.

1992 Stanley Cup playoffs

The 1992 Stanley Cup playoffs, the championship of the National Hockey League (NHL) began on April 18, after the conclusion of the 1991–92 NHL season. It was the 100th anniversary of the first awarding of the Stanley Cup, and it was won by the Pittsburgh Penguins, defeating the Chicago Blackhawks.

The 1992 playoffs saw history being made, as for the first time ever, all four division winners were eliminated in the same round. In the division finals, the Norris Division champion Detroit Red Wings were swept by the Chicago Blackhawks in four straight games, and the Montreal Canadiens, who had won the Adams Division, suffered the same fate at the hands of the Boston Bruins. The Pittsburgh Penguins eliminated the Patrick Division titlists, the New York Rangers, in six games, while the Vancouver Canucks, the Smythe Division toppers, fell to the Edmonton Oilers, also in six games.

A record 54 games were played in the first round, with six of the eight series going the full seven games, in addition three series featured teams coming back from 3–1 series deficits, the most in a single playoff year; this record was equaled in 2003. The only two series that didn't go seven games were the Oilers' six-game win over the Kings, and the Blackhawks' six-game win over the Blues.

This was the last year the Hartford Whalers and Minnesota North Stars qualified for the playoffs. The franchises would not reach the post-season again until 1999 and 1994 respectively. By the time each franchise reached the playoffs again, they were known as the Carolina Hurricanes and the Dallas Stars, respectively.

Video replay was used to decide a playoff game for the first time in game six of the Detroit–Minnesota division semifinal. Sergei Fedorov of the Red Wings appeared to hit the crossbar behind Minnesota goalie Jon Casey during the first overtime, but after the North Stars iced the puck immediately afterward, referee Rob Shick called for a video review, which determined that the puck had entered the goal just below the crossbar and caromed off the frame at the back of the net. Fedorov was awarded the goal, giving the Red Wings a series-tying victory.

1995 Stanley Cup playoffs

The 1995 Stanley Cup playoffs, the championship of the National Hockey League was played between May 6 and June 24, 1995. The sixteen teams that qualified, eight from each conference, played best-of-seven series for the conference quarterfinals, semifinals and championships, and then the conference champions played a best-of-seven series for the Stanley Cup. In the Final, the New Jersey Devils swept the favored Detroit Red Wings in four games to win their first championship.

This was the only time Patrick Roy missed the playoffs in his career. His team, the Montreal Canadiens, missed the playoffs for the first time since 1970. The Canadiens and the Ottawa Senators missed the playoffs this year. Montreal and Ottawa would not miss the playoffs in the same year again until 2016, when all Canadian teams missed the playoffs. The Quebec Nordiques played their last ever playoff series during this time. They would move to Denver, Colorado during the summer. For the first time since 1980, no league semifinal/conference final games were played in Canada.

1996 Stanley Cup playoffs

The 1996 Stanley Cup playoffs, the championship of the National Hockey League (NHL), began on April 16, 1996. The 16 teams that qualified (8 from each conference) played best-of-seven series for conference quarterfinals, semifinals and championships, and then the conference champions played a best-of-seven series for the Stanley Cup. These playoffs are noted as being the first playoffs in which all Canadian teams were eliminated during the first round. The New Jersey Devils, who had won the Stanley Cup the year before, failed to qualify for these playoffs. This was the first time that both Florida teams—the Florida Panthers and Tampa Bay Lightning—made it to the playoffs.

The playoffs ended on June 10 with the Colorado Avalanche sweeping the Florida Panthers in both teams' first-ever Finals appearance. It was Colorado's first-ever Stanley Cup championship in their inaugural season after relocating from Quebec City prior to the start of the regular season; in the previous years, they were known as the Quebec Nordiques. Joe Sakic was named playoff MVP and awarded the Conn Smythe Trophy.

For the second time in three years and the last time until 2013, all of the Original Six teams reached the playoffs. This is also the last time all three California-based teams missed the playoffs.

1997 Stanley Cup playoffs

The 1997 Stanley Cup playoffs, the championship of the National Hockey League (NHL), began on April 16, 1997, following the completion of the 1996–97 NHL season. The sixteen teams that qualified, eight from each conference, played best-of-seven series for conference quarter-finals, semi-finals and championships, and then the conference champions played a best-of-seven series for the Stanley Cup.

The Playoffs ended on June 7, with the Detroit Red Wings defeating the Philadelphia Flyers in a four-game sweep to win their eighth Stanley Cup championship in their history, and their first in 42 years. Red Wings goaltender Mike Vernon was awarded the Conn Smythe Trophy as the playoff's Most Valuable Player. It was also the first time since 1967 that the Boston Bruins failed to qualify to the playoffs, ending their 29-year consecutive playoffs appearances record.

Cluster diagram

A Cluster diagram or clustering diagram is a general type of diagram, which represents some kind of cluster. A cluster in general is a group or bunch of several discrete items that are close to each other.

The cluster diagram figures a cluster, such as a network diagram figures a network, a flow diagram a process or movement of objects, and a tree diagram an abstract tree. But all these diagrams can be considered interconnected: A network diagram can be seen as a special orderly arranged kind of cluster diagram. A cluster diagram is a mesh kind of network diagram. A flow diagram can be seen as a line type of network diagram, and a tree diagram a tree type of network diagram.

Dylan Walsh

Dylan Walsh (born Charles Hunter Walsh: November 17, 1963) is an American actor. He is best known for his role as Dr. Sean McNamara in the FX television series Nip/Tuck.

Globular cluster

A globular cluster is a spherical collection of stars that orbit a galactic core, as a satellite. Globular clusters are very tightly bound by gravity, which gives them their spherical shapes, and relatively high stellar densities toward their centers. The name of this category of star cluster is derived from the Latin, globulus—a small sphere. A globular cluster is sometimes known, more simply, as a globular.

Globular clusters are found in the halo of a galaxy and contain considerably more stars, and are much older, than the less dense, open clusters which are found in the disk of a galaxy. Globular clusters are fairly common; there are about 150 to 158, currently known globular clusters in the Milky Way, with, perhaps, 10 to 20 more, still undiscovered. Larger galaxies can have more: The Andromeda Galaxy, for instance, may have as many as 500. Some giant elliptical galaxies (particularly those at the centers of galaxy clusters), such as M87, have as many as 13,000 globular clusters.

Every galaxy of sufficient mass in the Local Group has an associated group of globular clusters, and almost every large galaxy surveyed, has been found to possess a system of globular clusters. The Sagittarius Dwarf galaxy, and the disputed Canis Major Dwarf galaxy appear to be in the process of donating their associated globular clusters (such as Palomar 12) to the Milky Way. This demonstrates how many of this galaxy's globular clusters might have been acquired in the past.

Although it appears that globular clusters contain some of the first stars to be produced in the galaxy, their origins and their role in galactic evolution are still unclear. It does appear clear that globular clusters are significantly different from dwarf elliptical galaxies and were formed as part of the star formation of the parent galaxy, rather than as a separate galaxy.

Jan Oort

Jan Hendrik Oort ( or ; 28 April 1900 – 5 November 1992) was a Dutch astronomer who made significant contributions to the understanding of the Milky Way and who was a pioneer in the field of radio astronomy. His New York Times obituary called him "one of the century's foremost explorers of the universe"; the European Space Agency website describes him as "one of the greatest astronomers of the 20th century" and states that he "revolutionised astronomy through his ground-breaking discoveries." In 1955, Oort's name appeared in Life magazine's list of the 100 most famous living people. He has been described as "putting the Netherlands in the forefront of postwar astronomy."Oort determined that the Milky Way rotates and overturned the idea that the Sun was at its center. He also postulated the existence of the mysterious invisible dark matter in 1932, which is believed to make up roughly 84.5% of the total matter in the Universe and whose gravitational pull causes "the clustering of stars into galaxies and galaxies into connecting strings of galaxies". He discovered the galactic halo, a group of stars orbiting the Milky Way but outside the main disk. Additionally Oort is responsible for a number of important insights about comets, including the realization that their orbits "implied there was a lot more solar system than the region occupied by the planets."The Oort cloud, the Oort constants, and the Asteroid, 1691 Oort, were all named after Jan Oort.

List of NGC objects (5001–6000)

This is a list of NGC objects 5001–6000 from the New General Catalogue (NGC). The astronomical catalogue is composed mainly of star clusters, nebulae, and galaxies. Other objects in the catalogue can be found in the other subpages of the list of NGC objects.

The constellation information in these tables is taken from The Complete New General Catalogue and Index Catalogue of Nebulae and Star Clusters by J. L. E. Dreyer, which was accessed using the "VizieR Service". Galaxy types are identified using the NASA/IPAC Extragalactic Database. The other data of these tables are from the SIMBAD Astronomical Database unless otherwise stated.

Messier object

The Messier objects are a set of 110 astronomical objects cataloged by the French astronomer Charles Messier in his Catalogue des Nébuleuses et des Amas d'Étoiles ("Catalogue of Nebulae and Star Clusters").

Because Messier was interested in finding only comets, he created a list of non-comet objects that frustrated his hunt for them. The compilation of this list, in collaboration with his assistant Pierre Méchain, is known as the Messier catalogue. This catalogue of objects is one of the most famous lists of astronomical objects, and many Messier objects are still referenced by their Messier number.

The catalogue includes some astronomical objects that can be observed from Earth's Northern Hemisphere such as deep-sky objects, a characteristic which makes the Messier objects extremely popular targets for amateur astronomers.A preliminary version first appeared in the Memoirs of the French Academy of Sciences in 1771,

and the last item was added in 1966 by Kenneth Glyn Jones, based on Messier's observations.

The first version of Messier's catalogue contained 45 objects and was published in 1774 in the journal of the French Academy of Sciences in Paris. In addition to his own discoveries, this version included objects previously observed by other astronomers, with only 17 of the 45 objects being Messier's.

By 1780 the catalogue had increased to 80 objects. The final version of the catalogue containing 103 objects was published in 1781 in the Connaissance des Temps for the year 1784.

However, due to what was thought for a long time to be the incorrect addition of Messier 102, the total number remained 102. Other astronomers, using side notes in Messier's texts, eventually filled out the list up to 110 objects.The catalogue consists of a diverse range of astronomical objects, ranging from star clusters and nebulae to galaxies. For example, Messier 1 is a supernova remnant, known as the Crab Nebula, and the great spiral Andromeda Galaxy is M31. Many further inclusions followed in the next century when the first addition came from Nicolas Camille Flammarion in 1921, who added Messier 104 after finding Messier's side note in his 1781 edition exemplar of the catalogue. M105 to M107 were added by Helen Sawyer Hogg in 1947, M108 and M109 by Owen Gingerich in 1960, and M110 by Kenneth Glyn Jones in 1967.

Shapley–Sawyer Concentration Class

The Shapley–Sawyer Concentration Class is a classification system on a scale of one to twelve using Roman numerals for globular clusters according to their concentration. The most highly concentrated clusters such as M75 are classified as Class I, with successively diminishing concentrations ranging to Class XII, such as Palomar 12. (The class is sometimes given with numbers [Class 1–12] rather than with Roman numerals.)

Timeline of epochs in cosmology

The timeline of cosmological epochs outlines the formation and subsequent evolution of the Universe from the Big Bang (13.799 ± 0.021 billion years ago) to the present day. An epoch is a moment in time from which nature or situations change to such a degree that it marks the beginning of a new era or age.

Times on this list are measured from the moment of the Big Bang.

See also

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