Messier 52 or M52, also known as NGC 7654, is an open cluster of stars in the northern constellation of Cassiopeia. It was discovered by Charles Messier on September 7, 1774. M52 can be seen from Earth with binoculars. The brightness of the cluster is influenced by extinction, which is stronger in the southern half.
R. J. Trumpler classified the cluster appearance as II2r, indicating a rich cluster with little central concentration and a medium range in the brightness of the stars. This was later revised to I2r, denoting a dense core. The cluster has a core radius of 2.97 ± 0.46 ly (0.91 ± 0.14 pc) and a tidal radius of 42.7 ± 7.2 ly (13.1 ± 2.2 pc). It has an estimated age of 158.5 million years and a mass of 1,200 M☉.
The magnitude 8.3 supergiant star BD +60°2532 is a probable member of M52. The stellar population includes 18 candidate slowly pulsating B stars, one of which is a δ Scuti variable, and three candidate γ Dor variables. There may also be three Be stars. The core of the cluster shows a lack of interstellar matter, which may be the result of supernovae explosions early in the cluster's history.
|Observation data (J2000 epoch)|
|Right ascension||23h 24m 48.0s|
|Declination||+61° 35′ 36″|
|Distance||4.6 kly (1.4 kpc)|
|Apparent magnitude (V)||5.0|
|Apparent dimensions (V)||13.0′|
|Mass||1,200 M☉ M☉|
|Estimated age||158.5 Myr|
|Other designations||C 2322+613, M 52, NGC 7654, OCl 260|
1997–98 Colorado Avalanche season
The 1997–98 Colorado Avalanche season was the Avalanche's third season.4 Cassiopeiae
4 Cassiopeiae is a wide binary star system in the northern constellation of Cassiopeia, located approximately 790 light-years away from the Sun. It is visible to the naked eye as a faint, red-hued star with a baseline apparent visual magnitude of 4.96. At the distance of this system, its visual magnitude is diminished by an extinction of 0.56 due to interstellar dust. This system is moving closer to the Earth with a heliocentric radial velocity of −39 km/s.The primary member of this system, component A, is an evolved red giant star, currently on the asymptotic giant branch, with a stellar classification of M2− IIIab. It is a suspected variable star of unknown type with a brightness that varies from visual magnitude 4.95 down to 5.00. As of 2011, the magnitude 9.88 secondary, component B, lay at an angular separation of 96.10″ along a position angle of 226° relative to the primary. In the sky, the open cluster Messier 52 is 40' to the south of it, near the constellation border with Cepheus.Chi Cassiopeiae
Chi Cassiopeiae (χ Cassiopeiae) is a solitary, yellow-hued star in the constellation Cassiopeia. It is visible to the naked eye with an apparent visual magnitude of +4.7. Based upon an annual parallax shift of 15.67 mas as seen from Earth, this system is located roughly 208 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction of 0.18 due to interstellar dust.With a stellar classification of G9 IIIb, it has the spectrum of an evolved, G-type giant star. It has an estimated age of a billion years and is a red clump star that it is generating energy through helium fusion at its core. The star has about double the mass of the Sun and has expanded to 11 times the Sun's radius. It is radiating 67.6 times the Sun's luminosity from its photosphere at an effective temperature of 4,746 K.HD 219623
HD 219623 is the Henry Draper Catalogue designation for a solitary star in the northern circumpolar constellation of Cassiopeia. It has an apparent visual magnitude of 5.59, which lies in the brightness range that is visible to the naked eye. According to the Bortle scale, it can be observed from dark suburban skies. Parallax measurements made by the Hipparcos spacecraft place it at an estimated distance of around 66.9 light years. It has a relatively high proper motion, advancing 262 milliarcseconds per year across the celestial sphere.This star has a stellar classification of F7 V, indicating that it is an F-type main-sequence star that is generating energy at its core through the thermonuclear fusion of hydrogen into helium. It is larger than the Sun, with 120% of the Sun's radius and 122% of the solar mass; as such, it shines nearly twice as brightly as the Sun. HD 219623 is around 1.2 billion years in age, with a projected rotational velocity of 5.5 km/s. Compared to the Sun, it has a slightly higher abundance of elements other than hydrogen and helium—what astronomers term the star's metallicity. The effective temperature of the stellar atmosphere is about 6,138 K, giving it the yellow-white hued glow of an ordinary F-type star.In 2006, this star was examined using the MIPS instrument on the Spitzer Space Telescope. An infrared excess at a wavelength of 70 μm was detected with 3-σ certainty. The data suggests the presence of circumstellar disk of orbiting dust, which is likely being replenished via debris from comets or asteroids. The temperature of this dust indicates the inner edge of the disk annulus comes to within 0.4 AU of the host star, while the outer edge extends out to around 22 AU.HR 273
HR 273 is a chemically peculiar spectroscopic binary system in the northern circumpolar constellation of Cassiopeia. It has an apparent visual magnitude of 5.9 making it faintly visible to the naked eye from dark suburban skies. Parallax measurements with the Hipparcos spacecraft put this system at a distance of roughly 350 light years.The primary, HR 273 A, is an Ap star and the secondary is an Am star, making this a very unusual binary system. The primary has a magnetic field of 65 gauss, amongst the weakest seen in any Ap star. The magnetic field in the secondary is too weak to detect.Component A has a spectral type of A0 III, and has unusually strong lines of strontium, chromium, and europium so it is known as a SrCrEu star. Although some spectral lines of the secondary star can be clearly distinguished, its spectral type cannot be clearly assigned. It is thought to be a late class A star, cooler than the primary. The primary star has been rotationally braked so that its rotational period closely matches its orbital period.HR 297
HR 297 is a solitary star in the northern circumpolar constellation of Cassiopeia. It has an apparent visual magnitude of 5.8, making it faintly visible to the naked eye from dark suburban skies. Parallax measurements with the Hipparcos spacecraft put this system at a distance of roughly 263 light years.This is an F-type main sequence star with a stellar classification of F7V. Because of the stability of this star, it is used as a standard in the photometric WBVR system. The angular diameter of this star has been measured directly using the CHARA Array, yielding an estimate of 4.5 times the diameter of the Sun. Stellar models suggest a mass equal to about twice that of the Sun, with 25 times the Sun's luminosity.This is a young star with an estimated age of 1.3 billion years. It is rotating rapidly, with a projected rotational velocity of 42 km/s. The abundance of elements other than hydrogen and helium is about the same as that in the Sun. The effective temperature of the stellar atmosphere is 6,089 K, giving it the yellow-white hued glow of an F-type star.This star has been examined for the presence of an infrared excess, but no statistically significant amount was detected. The detection of such an excess can indicate the presence of a dusty circumstellar disk.List of NGC objects (7001–7840)
This is a list of NGC objects 7001–7840 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.List of open clusters
This is a list of open clusters located in the Milky Way. An open cluster is a gravitationally bound association of up to a few thousand stars that all formed from the same giant molecular cloud. There are over 1,000 known open clusters in the Milky Way galaxy, but the actual total may be up to ten times higher. The estimated half lives of clusters, after which half the original cluster members will have been lost, range from 150 million to 800 million years, depending on the original density.M52
M52, M/52 or M-52 may refer to:
M52 highway (Russia)
MEMS M-52/60, a submachine gun
M52 rifle grenade
M52 Self Propelled Howitzer, a 1950s US self-propelled 105mm Artillery, used by the Turkish Land Forces
BMW M52, a 1994 automobile piston engine
Miles M.52, a 1942 British supersonic jet project
Messier 52, an open star cluster in the constellation Cassiopeia
M-52 (Michigan highway)
M52, a Metrobus route in Sydney, AustraliaMessier 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.NGC 7635
NGC 7635, also known as the Bubble Nebula, Sharpless 162, or Caldwell 11, is an H II region emission nebula in the constellation Cassiopeia. It lies close to the direction of the open cluster Messier 52. The "bubble" is created by the stellar wind from a massive hot, 8.7 magnitude young central star, SAO 20575 (BD+60°2522). The nebula is near a giant molecular cloud which contains the expansion of the bubble nebula while itself being excited by the hot central star, causing it to glow. It was discovered in 1787 by William Herschel. The star BD+60°2522 is thought to have a mass of about 44 M☉.Nu Cassiopeiae
Nu Cassiopeiae, Latinized from ν Cassiopeiae, is a solitary star in the northern constellation of Cassiopeia. With an apparent visual magnitude of +4.89, it is a faint star but visible to the naked eye. Based upon an annual parallax shift of 7.92 mas as seen from Earth, this star is located around 410 light years from the Sun. Cowley et al. (1969) catalogued this star with a stellar classification of B9 III, indicating it has the spectrum of an evolved B-type giant star. However, Palmer et al. (1968) assigned it a class of B8 V, which would instead suggest it is an ordinary B-type main-sequence star.Omega Cassiopeiae
Omega Cassiopeiae (ω Cassiopeiae) is a binary star system in the northern constellation of Cassiopeia. It has a combined apparent visual magnitude of +4.99, which means it is a faint star but visible to the naked eye. Based upon an annual parallax shift of 4.65 mas as seen from Earth, this system is located roughly 700 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction of 0.16 due to interstellar dust.This is a single-lined spectroscopic binary star system with an orbital period of 69.92 days and an eccentricity of 0.30. The visible component has the spectrum of an evolved, B-type giant star with a stellar classification of B8 III. It is a helium-weak star, a type of chemically peculiar star that displays abnormally weak absorption lines of helium for a star of its temperature. Omega Cassiopeiae has an estimated 4.7 times the mass of the Sun and is radiating 488 times the Sun's luminosity from its photosphere at an effective temperature of around 12,737 K.Pi Cassiopeiae
Pi Cassiopeiae, Latinized from π Cassiopeiae, is a close binary star system in the constellation Cassiopeia. It is visible to the naked eye with an apparent visual magnitude of +4.949. Based upon an annual parallax shift of 18.63 mas as seen from Earth, this system is located about 175 light years from the Sun.
This is a double-lined spectroscopic binary system with an orbital period of nearly two days in a circular orbit. It is classified as a rotating ellipsoidal variable star and its brightness varies by 0.02 magnitudes with a period of 23.57 hours, which equals half of its orbital period. The spectrum matches that of an A-type main-sequence star with a stellar classification of A5 V.Psi Cassiopeiae
Psi Cassiopeiae (ψ Cassiopeiae) is a binary star system in the northern constellation of Cassiopeia.
The primary component, ψ Cassiopeiae A, is an orange K-type giant with an apparent magnitude of +5.0; it is a double star, designated CCDM J01259+6808AB, with a fourteenth magnitude star (component B) located 3 arcseconds from the primary. Located about 25 arcseconds distant there is a 9.8 magnitude optical companion CCDM J01259+6808CD, designated ψ Cassiopeiae B in older star catalogues, which is itself another double; CD comprises a 9.4 magnitude component C and a 10 magnitude component D.Tau Cassiopeiae
Tau Cassiopeiae (τ Cassiopeiae) is a solitary, orange hued star in the northern constellation of Cassiopeia. It is bright enough to be seen with the naked eye, having an apparent visual magnitude of +4.86. Based upon an annual parallax shift of 18.75 mas as seen from Earth, this system is located about 174 light years from the Sun.
The spectrum of this star indicates it is an evolved, K-type giant star with a stellar classification of K1 IIIa. It is a suspected variable star of unknown type. Tau Cassiopeiae is 3.9 billion years old with about 1.44 times the mass of the Sun and 10 times the Sun's radius. It is radiating 40 times the Sun's luminosity from its expanded photosphere at an effective temperature of around 4,617 K.Theta Cassiopeiae
Theta Cassiopeiae (θ Cas, θ Cassiopeiae) is a solitary star in the northern constellation of Cassiopeia. It shares the traditional name Marfak with μ Cassiopeiae to the southeast, which is derived from the Arabic term Al Marfik or Al Mirfaq (المرفق), meaning "the elbow". At an apparent visual magnitude of 4.3, it is visible to the naked eye. Based upon an annual parallax shift of 24.42 mas, it is located about 134 light years from the Sun. It has a total annual proper motion of 0.227 arcseconds per year.In Chinese, 閣道 (Gé Dào), meaning Flying Corridor, refers to an asterism consisting of θ Cassiopeiae, ι Cassiopeiae, ε Cassiopeiae, δ Cassiopeiae, ν Cassiopeiae and ο Cassiopeiae. Consequently, θ Cassiopeiae itself is known as 閣道四 (Gé Dào sì, English: the Fourth Star of Flying Corridor.)This is an A-type main sequence star with a stellar classification of A7 V. The measured angular diameter of this star is 0.58±0.02 mas, which, at the estimated distance of this star, yields a physical size of about 2.6 times the radius of the Sun. It is about 650 million years in age and is spinning with a projected rotational velocity of 103 km/s. This is a candidate Vega-type system, which means it displays an infrared excess suggesting it has an orbiting debris disk. It is a suspected Delta Scuti variable.Upsilon1 Cassiopeiae
Upsilon1 Cassiopeiae (υ1 Cassiopeiae) is an astrometric binary star system in the northern constellation of Cassiopeia. It is visible to the naked eye with an apparent visual magnitude of 4.82. Based upon an annual parallax shift of 9.93 mas as seen from Earth, this system is located about 330 light years from the Sun.
The visible component is an evolved K-type giant star with a stellar classification of K2 III. With an estimated age of 4.75 billion years, it is a red clump star that is generating energy through the fusion of helium at its core. The measured angular diameter, after correction for limb darkening, is 1.97±0.02 mas. At the estimated distance of the star, this yields a physical size of about 21 times the radius of the Sun. It has 1.39 times the mass of the Sun and is radiating 174 times the Sun's luminosity from its expanded photosphere at an effective temperature of 4,422 K.There is a magnitude 12.50 visual companion at an angular separation of 17.80 arc seconds along a position angle of 61°, as of 2003. A more distant magnitude 12.89 companion lies at a separation of 93.30 arc seconds along a position angle of 125°, as measured in 2003. Neither star appears to be physically associated with υ1 Cas.Xi Cassiopeiae
Xi Cassiopeiae (ξ Cassiopeiae) is a blue-white hued binary star system in the northern constellation of Cassiopeia. It has an apparent visual magnitude of +4.81 and thus is faintly visible to the naked eye. Based upon an annual parallax shift of 2.28 mas as seen from Earth, this system is located roughly 1,400 light years from the Sun. At that distance, the visual magnitude of the system is diminished by an extinction factor of 0.20 due to interstellar dust. It is advancing in the general direction of the Sun with a radial velocity of roughly −10.6 km/s.This is a single-lined spectroscopic binary star system with an orbital period of 940.2 days and an eccentricity of 0.4. The visible component has the spectrum of a B-type main-sequence star with a stellar classification of B2.5 V. It has an estimated 10.1 times the mass of the Sun and around 4.5 times the Sun's radius. At the age of 19 million years, it has a high rate of rotation with a projected rotational velocity of about 139 km/s. The star is radiating 2,873 times the Sun's luminosity from its photosphere at an effective temperature of around 15,585 K.
New General Catalogue 7500 to 7840