| Messier 71 | |
| Observation data (J2000 epoch) | |
|---|---|
| Class | X-XI |
| Constellation | Sagitta |
| Right ascension | 19h 53m 46. In Astronomy, an epoch is a moment in time used as a reference for the Orbital elements of a Celestial body. In Astronomy, an epoch is a moment in time used as a reference for the Orbital elements of a Celestial body. 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 In common usage a constellation is a group of celestial bodies that are connected together in some arrangement typically stars to form a visible figure or picture This article is about the constellation for the trigonometric function see Versine. Right ascension (abbrev RA; symbol α) is the Astronomical term for one of the two Coordinates of a point on the Celestial sphere 11s[1] |
| Declination | +18° 46′ 42. In Astronomy, declination (abbrev dec or δ) is one of the two coordinates of the Equatorial coordinate system, the other being either 3″[1] |
| Distance | 12 kly (3. A light-year or light year (symbol ly) is a unit of Length, equal to just under ten trillion Kilometres As defined by 7 kpc) |
| Apparent magnitude (V) | +6. History The first direct measurements of an object at interstellar distances were undertaken by German Astronomer Friedrich Wilhelm Bessel in 1838 The apparent magnitude ( m) of a celestial body is a measure of its Brightness as seen by an observer on Earth, normalized to the value 1[1] |
| Apparent dimensions (V) | 7′. 2 |
| Physical characteristics | |
| Mass | kg ( M ) |
| Radius | 13 ly[2] |
| Estimated age | 9-10 Gyr |
| Other designations | M71, NGC 6838, GCl 115[1] |
| See also: Globular cluster, List of globular clusters | |
Messier 71 (also known as M71 or NGC 6838) is a globular cluster in the constellation Sagitta. The solar mass is a standard way to express Mass in Astronomy, used to describe the masses of other Stars and galaxies. The New General Catalogue ( NGC) is the best-known catalogue of Deep sky objects in Amateur astronomy. A globular cluster is a spherical collection of Stars that orbits a galactic core as a Satellite. This is a list of Globular clusters. The apparentmagnitude does not include an extinction correction A globular cluster is a spherical collection of Stars that orbits a galactic core as a Satellite. In common usage a constellation is a group of celestial bodies that are connected together in some arrangement typically stars to form a visible figure or picture This article is about the constellation for the trigonometric function see Versine. It was discovered by Philippe Loys de Chéseaux in 1746 and included by Charles Messier in his catalog of comet-like objects in 1780. Jean-Philippe Loys de Chéseaux (1718&ndash1751 was an astronomer from Lausanne in Switzerland. Year 1746 ( MDCCXLVI) was a Common year starting on Saturday (link will display the full calendar of the Gregorian calendar (or a Charles Messier ( June 26, 1730 &ndash April 12, 1817) was a French astronomer most notable for publishing an A comet is a small Solar System body that orbits the Sun and when close enough to the Sun exhibits a visible coma (atmosphere or a tail — Year 1780 ( MDCCLXXX) was a Leap year starting on Saturday (link will display the full calendar of the Gregorian calendar (or a It was also noted by Koehler at Dresden around 1775. Johann Gottfried Koehler ( December 15, 1745 – September 19, 1801) was a German Astronomer who discovered a number of Dresden (etymologically from Old Sorbian Drežďany, meaning people of the riverside forest, Drježdźany is the Capital city of the German Year 1775 ( MDCCLXXV) was a Common year starting on Sunday (link will display the full calendar of the Gregorian calendar (or a
M71 is at a distance of about 12,000 light years away from Earth and spans some 27 light years across. A light-year or light year (symbol ly) is a unit of Length, equal to just under ten trillion Kilometres As defined by EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 The irregular variable star Z Sagittae is a member of this cluster. For the astronomical object see Variable star. Variable Star is a 2006 novel written by Spider Robinson
M71 was long thought (until the 1970s) to be a densely packed open cluster and was classified as such by leading astronomers in the field of star cluster research due to its lacking a dense central compression , its stars having more "metals" than is usual for an ancient globular cluster, and further its lacking the RR Lyrae "cluster" variable stars that are common in most globulars. This article is about the Decade 1970-1979 For the Year 1970 see 1970. An open cluster is a group of up to a few thousand Stars that were formed from the same Giant molecular cloud, and are still loosely gravitationally Historically Astronomy was more concerned with the classification and description of phenomena in the sky while Astrophysics attempted to explain these phenomena In Astronomy and Physical cosmology, the metallicity of an object is the proportion of its matter made up of Chemical elements other than Hydrogen RR Lyrae variables are Variable stars often used as Standard candles RR Lyrae are pulsating Horizontal branch stars with a mass of around half the However, modern photometric photometry has detected a short "horizontal branch" in the H-R diagram of M71, which is characteristic of a globular cluster. Photometry is a technique of Astronomy concerned with measuring the Flux, or intensity of an Astronomical object 's Electromagnetic The horizontal branch ( HB) is a stage of Stellar evolution which immediately follows the Red giant branch in stars whose masses are similar to the Sun's The Hertzsprung-Russell diagram (usually referred to by the abbreviation H-R diagram or HRD, also known as a colour-magnitude diagram, or CMD The shortness of the branch explains the lacking of the RR Lyrae variables and is due to the globular's relatively young age of 9-10 billion years. The relative youth of this globular also explains the abundance of "metals" in its stars. Hence today, M71 is designated as a very loosely concentrated globular cluster, much like M68 in Hydra. Messier 68 (also known as M68 or NGC 4590) is a Globular cluster in the Hydra constellation. Hydra (ˈhaɪdrə is the largest of the 88 modern Constellations and was also one of the 48 constellations listed by Ptolemy. M71 has a luminosity of around 13,200 suns. Luminosity has different meanings in several different fields of science
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