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C A N C E R

 

ori.gif (1448 bytes) Mythologya and history

Mitología de Cáncer

   The history of the celestial Crab called Cancer takes to the adventures of Hercules and their twelve arduous works to us. The heroic Hercules was another son of Zeus, born ilegítimamente of a mortal mother.

    Juno (or Hera), wife of Zeus, jealous of that divine infidelity, decided to take revenge themselves in the sprout, since Zeus was beyond his reprimands. For that reason, it invoked several terrible punishments against the young hero, including the one of madness; finally, it gave like slave to a Greek king, who imposed 12 works to him (hercúleos); after fulfilling them without failing no, it would leave it in freedom.

     The second work was the one to kill the Hidra de Lerna, a frightful creature of the marshes whose breath is poisonous, of enormous body and that has 8 or 9 heads of serpent. If the head of the center is cut, immediately it returns to grow of double size.

     Hera, contemplating the encounter of Hercules with Hidra, decided to take part in favor of the monster and sent a gigantic crab so that it distracted the hero, when attacking it with its pliers. Cancer, the Crab, was thus sentry of the Hidra and a creature of the Gods. Juno compensated to him by its action although it was useless, giving a place him between stars near the victim of another one of the works of Hercules, Leon.

     The Crab is a very resistant and old species. It is armed of a shell and it is equipped of pliers like arms; he is energetic and it strikes quickly to his predators and without no fear.

     But the Greeks, on the contrary, saw in her two asses (represented, in individual, by stars g and d), thus honoring the animals that helped to Jupiter in their fight against the giants. To his presence he must the definition of Posebre that occurs to the greatest cluster. Schiller, in its reestrucuturación in Christian key of the constellations, assimilated the Crab to San Juan Evangelista

 

Characteristics

       It is a constellation that is a total star absence shining the area of the sky that occupies Cancer extends good part of the line that unites to luminous b Geminorum with Regulus or a Leonis. It limits the north with Lynx, to the east with Gemini and Canis Minor, to the south with the Hydra and the west with I read is between the parallels 10º and North 30º therefore, visible during the months of November to April in the North hemisphere and during the austral summer in the south. The ecliptic crosses by half the constellation between end of Julio and principles of August.

    Cancer is to 30º North al of the milky Route, by as much, is characterized to be observed two precious stellar and many double star, weak accumulations of brightness. It includes 500º square of sky.

    The constellation of Cancer I located   January 2nd, 1982 to a the age of 14 years-old.

 

Constelación de Cancer

 

Main stars

       Alpha, a; denominated Acubens, Sertan or Sartan,  or the pliers, of magnitude 4.30, almost white yellow color. Light of us is to 170 years and is fifty times more luminous than our Sun Is a visual binary system with a companion of magnitude 11.0 to main, visible 11"of the secondary one with medium telescopes.

     Beta, b; denominated Altarf, of magnitude 3.5 being most shining of the constellation. One is in the South limit of the constellation next to the Hydra.  Light is to 290 years, is of orange color. It forms a binary system with a white dwarf of magnitude 14 to 29", visible with great telescopes.

     Gamma, g; call also Asellus Borealis or ass of the north as it defined Tolomeo in his Almagesto.  Of brightness 4,6, white  and that is to 158 years light of us.

     Delta, d; call  Asellus Australis or ass of the south, located in the center of the constellation and peculiarly the ecliptic one happens to only 3' of arc to the south of the star.  Of 4,2 magnitude and yellow color light  is to 136 years.

     Iota, i; one is in the North zone of the constellation, of yellow color and of magnitude 4.20 light of us is to 300 years. It forms a binary system separated to 30"of arc. 

Other objets

     M 44 or the Praesebre, wonderful cluster of 3.10 magnitude combine at first visible. The ass of north or g and the ass of the south or d are between . Bayer astronomer observed it as a star and catalogued as and Cancri whose star is immersed in the cluster. Galileo solved this agglomeration contanto 36 stars. But already he was famous in the antiquity, in fact, Pliny the Old one mentions it like trustworthy indicator of the metereológico time. It is a physical system distributed on a relatively great zone 95' of arc. Light of us is to 590 years and moves to todsas stars of the accumulation to a 27 speed of km/s. Tiene an age of 660 million years.

     M 67, another precious cluster located to the south of the constellation, formed by five hundred stars that are to 2400 years light of us. He is much more old that the Manger, its age is considered in 3.900 million years. It has an angular diameter of 30' of arc.

 

ori.gif (1448 bytes) Observations by telescope

D O U B L E

Nom:S 1177 R.A.: 08h.03m.

Dec: 27º40'

Mag: 6.5, 7.3 Sep.: 3.5" P.A.: 354º Nat:f? Spec.:F,A
AOC: 94 DSC: 67 D. of S.D.: 00-Ene.-1984

sigma1177

    NOTE: One is in a partially rich zone; it is one double that emphasizes on the field, therefore, his identification it is simple, it is unfolded with the eyeglass of 100x, being a slight difference of magnitude between the components.

 

D O U B L E

Nom:OS 97 R.A.: 09h.05m.

Dec: 24º44'

Mag: 8.5,8.5 Sep.: 51" P.A.: 58º Nat:? Spec.:K,A
AOC: 533 DSC: 381 D. of S.D.: 19h.18m.(UT);16-Mar.-1986 (prisma)

osigma97

   NOTE: One is in a poor zone; both components have the same magnitude, is the star most shining of the field and therefore, it does not present/display difficulty at the time of unfolding it with the eyeglass of 50x.

 

D O U B L E

Nom:S 1283 R.A.: 08h.47m.

Dec: 15º01'

Mag: 7.0, 8.1 Sep.: 16" P.A.: 124º Nat:? Spec.:K,A
AOC: 534 DSC: 382 D. of S.D.: 19h.38m.(UT);16-Mar.-1986 (Prisma)

sigma1283

      NOTE: One is in a quite poor zone; they are not very separated, there is a remarkable difference of magnitude, is unfolded without difficulty with the eyeglass of 50x.

 

D O U B L E

Nom: z R.A.: 08h.09m.

Dec: 17º48'

Mag: 5.4, 6.1 Sep.: 6.0" P.A.: 82º Nat: O Spec.:B,A
AOC: 535 DSC: 383 D. of S.D.: 19h.39m.(UT);16-Mar.-1986 (Prisma)

zeta

   NOTE: One is in a partially rich zone, is a small difference of magnitude between the components, is one double precious, easy to locate is unfolded with the eyeglass of 50x.

 

CLUSTER

NGC:2632

M:44

R.A.: 08h.37m.

Dec: 20º00'

Mag:3.7

Dim: 95' AOC: 548 N.& C.O.C. 153
D. of S.D.: 20h.23m.(UT);01-Abr.-1986 (prisma)  

m44

    NOTE: It is the famous stellar accumulation of the Manger, is in a rich zone; it is a shining, enormous stellar accumulation, nothing less than 95', is formed by one 140 stars of different magnitude, in the center of the stellar accumulation emphasizes three shining and precious triangles, emphasizes two steps of magnitudes in the accumulation, one formed by 23 stars, and the rest one hundred twenty of weak brightness. It is a formed stellar accumulation solely by fifty stars, although many are observed more, this makes suppose that intrusas emphasizes, is a moderate concentration towards the center, is to 160 pársec, the phantom of stars more young person is A0, and has an age of 660 million years.

 

CLUSTER

NGC:2682

M:67

R.A.: 08h.48m.

Dec: 12º00'

Mag:6.1

Dim:15' AOC: 549 N.& C.O.C. 154
D. of S.D.: 20h.45m.(UT);01-Abr.-1986 (Prisma)  

m67

    NOTE: One is in a very rich zone; it is a very pretty stellar accumulation and very grouped in only 15', it is observed totally granulated, telling at first sight 60 stars, his form is irregular but very similar to M11 in Scutum; it comes to be a semicircle in which an entrance of 5' exists, this figure is maintained by five stars in sense N-S only 4' of the accumulation; it is formed by two hundred stars, 60 are solely visible with the R-90mm.; is located to 800 pársec, and has an age of 3,200 million years, with the phantom of the youngest star is of the type B8.

 

D O U B L E

Nom:24 R.A.: 08h.24m.

Dec: 24º42'

Mag: 7.0,7.5 Sep.: 5.9" P.A.: 57º Nat:f? Spec.:A,G
AOC: 760 DSC: 559 D. of S.D.: 22h.36m.(UT);28-Feb.-1987 (Prisma)

24

    NOTA: One is in a partially rich zone, 6; there is a small difference of magnitude, are slightly together, is possible to mention that one is a triple, but components BC comprise of one double espectrocópica, unfolds with an eyeglass of 50x the ABC component the colors I do not distinguish them due to the brightness weakness, is one pretty double

 

D O U B L E

Nom:F2 R.A.: 08h.24m.

Dec: 27º06'

Mag: 6.0,6.4 Sep.: 5.3" P.A.: 217º Nat:ph Spec.:A,A
AOC:761 DSC: 560 D. of S.D.: 22h.40m.(UT);28-Feb.-1987

D O U B L E

Nom: F1 R.A.: 08h.24m.

Dec: 26º45'

Mag: 9.0,9.5 Sep.: 10" P.A.: 15º Nat:? Spec.:?,?
AOC: 762 DSC: 561 D. of S.D.: 22h.41m.(UT);28-Feb.-1987

D O U B L E

Nom: No catalog. R.A.: 08h.23m.

Dec: 26º36'

Mag: 9.5,9.5 Sep.: 10" P.A.: 270º Nat:? Spec.:?
AOC: 763 DSC: 562 D. of S.D.: 22h.41m.(UT);28-Feb.-1987 (Prisma)

fi2

    NOTA: F2: One is in a somewhat rich zone; there is a small difference of magnitude, are slightly together, is unfolded with the eyeglass of 100x, both components are white, is one pretty double.

    F1: It's locates to 20' to souht of  F2; it is one weak double but pretty, not very separated, profit not to identify the colors by the weakness of the components, is unfolded without difficulty with the eyeglass of 50x.

    CED562: To 15' of the previous one, one is another double catalogued but not identified in Sky Catalogue 2000,0 vol. 2, both components seem to have the same magnitude, profit not to identify the colors, due to the brightness weakness. The set in general is pretty by being able to observe nothing less than three doubles in the same field

 

D O U B L E

Nom:S 1245 R.A.: 08h.36m.

Dec: 06º37'

Mag: 6.0,7.2 Sep.: 10.3" P.A.: 25º Nat:? Spec.:F,G
AOC: 910 DSC: 692 D. of S.D.: 21h.56m.(UT);04-Mar.-1989 (Prisma)

sigma1245

   NOTE: One is in a rich zone; there is a slight difference of brightness between the components, the main one I see yellow it, and the secondary one seems to me white, is unfolded without difficulty with the eyeglass of 50x

 

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