sexta-feira, 3 de fevereiro de 2017

A longa e sinuosa constelação Hydra, a Hidra Fêmea


Olá!

Caro Leitor,
a constelação da Hidra Fêmea, Hydra, 
é composta por estrelinhas bem tímidas
- com a boa exceção de sua estrela-alpha Alphard! -,
que vão desenhando a figura de um longo corpo
enrolando-se e enredilhando-se e serpenteando
 através um longo espaço dos céus estrelados!
- quase como que realizando uma linha divisória 
entre algumas constelações do Zodíaco
- Virgem, Leão e Caranguejo -
(com o Corvo e a Taça e o Sextante 
colados ao corpo da Hidra
voltado para o norte)
e constelações mais ao sul
- Centauro, Lobo, Navio (Quilha, Popa e Vela)
(com as constelações Máquina Pneumática (Antlia) 
e Bússola (Pyxis)
coladas ao corpo da Hidra voltado para o sul)!


É sempre uma emoção podermos visualizar a Hydra 
por inteiro e a olho nú...,
afinal, é maior constelação em termos de área ocupada!

No entanto, 
é sempre importante que estejamos sob céus escuros e transparentes
e em noites de ausência de Lua!


Stellarium




É sempre bem interessante que possamos divisar
a Cabeça da Hidra
que se posiciona um tantinho ao sul da tímida constelação do Caranguejo
- onde podemos também divisar a olho nú, usando nossa visão enviesada,
a Colmeia de Abelhas ou Presépio ou Objeto Messier 44 ou Manjedoura
ou Berçário de Estrelas!

Stellarium




A Cabeça da Hydra é considerada como um Asterismo 
formado pelas estrelas Epsilon, Delta, Zeta, Ro, Eta, Sigma 
e suas magnitudes vão desde quase 4,
passando por 5 e por 6 e 12 e ainda além.


Stellarium



Certamente, após termos divisado o objeto celeste Presépio
e, um tantinho ao sul, o Asterismo formando a cabeça da Hidra,
nos deixamos encantar diante de
o coração da Hydra sugerido pela estrela-alpha Hydrae, Alphard,
maravilhosamente amarelada/alaranjada e esmaecida 
- porém a mais brilhante
de toda esta longa constelação!


Stellarium




Como você poderá perceber,
Caro Leitor,
a constelação da Hydra é composta por estrelinhas bem tímidas
- com a boa exceção de sua estrela-alpha Alphard, é claro! -,
que vão desenhando a figura de um longo corpo enrolando-se
e enredilhando-se através um longo espaço dos céus estrelados!




http://hubblesite.org/newscenter/archive/releases/2013/23/video/b/still/1/



Nesta Postagem,
estaremos comentando um tantinho 
sobre a belíssima (e tímida) 
constelação da Hydra, a Hidra Fêmea,
 a mais longa constelação no céu 
e também a maior em termos de área ocupada. 

Esta constelação é composta de estrelinhas 
que vão se enroscando, serpenteando através os céus estrelados
- quase como que realizando uma linha divisória
 entre algumas constelações do Zodíaco:

A cabeça da Hydra é um asterimo 
que surge acima do equador 
em direção à constelação de Câncer, o Caranguejo.

O coração da Hydra é sugerido pela estrela-alpha Hydrae, Alphard,
maravilhosamente amarelada/alaranjada e esmaecida 
- porém a mais brilhante
de toda esta longa constelação!

O corpo de cobra vai serpenteando através o céu do sul,
 começando em Câncer e tendo o Leão ao norte, 
depois o Sextante e então a Taça e o Corvo
 e ainda Virgem até terminar sua cauda fina em Libra, a Balança.
Ao sul, a Hydra faz seus encontros com o Cão Menor, 
o Monoceros, a Popa do Navio, o Peixe Austral, 
Antlia e o Centauro.

Nesta Postagem,
estaremos comentando 
sobre a constelação da Hydra e suas estrelas.

Em Postagens seguintes,
Caro Leitor,
você encontrará informações
sobre os Obejtos Messier
encontrados nesta constelação.
(M48, M68 e M83)

No enrolar ou enredilhar do longo corpo sinuoso

 e serpenteado da Hydra,
existe uma fantástica Nebulosa Planetária
 denominada de O Fantasma de Júpiter, NGC 3242


Existe a belíssima imagem 
realizada através a interação entre duas Galáxias, 
uma espiral e outra elíptica
- NGC 2936 e NGC 2937 -
formando o Objeto denominado ARP 142
ora 
chamado de Pingüim (e seu ovo)
ou
ora chamado Golfinho... ou Boto...
e também, quem sabe, figurando um passarinho....

326 milhões de anos nos separam desta maravilha!  

É UMA DANÇA CÓSMICA!


Realmente, Hydra é uma constelação interessantíssima
de ser observada a olho nú
- somente em noites de céus escuros e transparentes
e de ausência da luminosidade da Lua!

E, através potentes telescópios,
Hydra é, certamente, uma constelação
que nos apresenta Objetos Celestes de tirar o fôlego!

Boa Observação e Bons Estudos!

Com um abraço estrelado,
Janine Milward




Mario Jaci Monteiro - As Constelações, Cartas Celestes




 HYDRA, A HIDRA FÊMEA

Posicionamento:
Ascensão Reta  8h8m / 14h58m    Declinação +6o.8 / -35o.3

Mito:
Esta constelação representa a serpente marinha encontrada pelo Corvo 
e usada como desculpa para que não tenha podido trazer a água na Taça 
na missão solicitada por Apollo.

Algumas Informações Interessantes acerca esta Constelação:
Hydra é a mais longa constelação no céu e também a maior em termos de área ocupada.

Fronteiras:
 A cabeça da Hydra surge acima do equador 
em direção à constelação de Câncer, o Caranguejo, 
e seu corpo de cobra vai serpenteando através o céu do sul, 
começando em Câncer e tendo o Leão ao norte, depois o Sextante 
e então a Taça e o Corvo e ainda Virgem 
até terminar sua cauda fina em Libra, a Balança. 
Ao sul, a Hydra faz seus encontros com o Cão Menor, 
o Monoceros, a Popa do Navio, o Peixe Austral, Antlia 
e o Centauro.


6a. Edição do Atlas Celeste
de autoria de Ronaldo Rogério de Freitas Mourão,
Editora Vozes, Petrópolis, ano de 1986


http://www.iau.org/static/public/constellations/gif/HYA.gif


Estrelas, em Hydra:

A Cabeça da Hydra é considerada como um Asterismo
 formado pelas estrelas Epsilon, Delta, Zeta, Ro, Eta, Sigma 
e suas magnitudes vão desde quase 4, passando por 5 e por 6 e 12 
e ainda além.

Alphard.  Alpha Hidrae
Ascensão Reta 09h 26,6m - Declinação - 08o 35’
Magnitude visual 2,16 - distância 94 anos-luz
Uma estrela laranja no pescoço da Hidra.  De Al Fard al Shuja,  A Estrela Solitária na Serpente.  Freqüentemente chama de O Coração da Hidra.

U Hydrae - Estrela Variável Irregular
Ascensão Reta 10h35m    Declinação -13o.07
Magnitudes: Max 4,8  Min 5,9  
Tipo IRR    Espectro N2

R Hydrae - Estrela Variável
Ascensão Reta  13h26m       Declinação -23o.01
Magnitudes:  Max 3,5     Min  10,9      Período 387,0
Tipo PLG     Espectro M7e

W Hydrae - Estrela Variável
Ascensão Reta 13h46m           Declinação -28o.07
Magnitudes:  Max 6,5    Min   8,0       Período 380,0
Tipo   PLG       Espectro M4e

6a. Edição do Atlas Celeste
de autoria de Ronaldo Rogério de Freitas Mourão,
Editora Vozes, Petrópolis, ano de 1986


http://en.wikipedia.org/wiki/File:HydraCC.jpg

Description
English: Photography of the constellation Hydra, the water snake
Deutsch: Fotografie des Sternbildes Hydra, der Wasserschlange
Date
SourceOwn workAlltheSky.com
Author




Hydra is the largest of the 88 modern constellations, measuring 1303 square degrees. Also one of the longest at over 100 degrees, its southern end abuts Libra and Centaurus and its northern end borders Cancer.[1] It has a long history, having been included among the 48 constellations listed by the 2nd century astronomer Ptolemy. It is commonly represented as a water snake. It should not be confused with the similarly named constellation of Hydrus.

Features

The constellation Hydra as it can be seen by the naked eye.

Stars

Despite its size, Hydra contains only one reasonably bright starAlphard, designated Alpha Hydrae. It is an orange giant of magnitude 2.0, 177 light-years from Earth. Its traditional name means "the solitary one". Beta Hydrae is a blue-white star of magnitude 4.3, 365 light-years from Earth. Gamma Hydrae is a yellow giant of magnitude 3.0, 132 light-years from Earth.[1]
Hydra has one bright binary starEpsilon Hydrae, which is difficult to split in amateur telescopes; it has a period of 1000 years and is 135 light-years from Earth. The primary is a yellow star of magnitude 3.4 and the secondary is a blue star of magnitude 6.7. However, there are several dimmer double stars and binary stars in Hydra. 27 Hydrae is a triple star with two components visible in binoculars and three visible in small amateur telescopes. The primary is a white star of magnitude 4.8, 244 light-years from Earth. The secondary, a binary star, appears in binoculars at magnitude 7.0 but is composed of a magnitude 7 and a magnitude 11 star; it is 202 light-years from Earth. 54 Hydrae is a binary star 99 light-years from Earth, easily divisible in small amateur telescopes. The primary is a yellow star of magnitude 5.3 and the secondary is a purple star of magnitude 7.4.[1] N Hydrae (N Hya) is a pair of stars of magnitudes 5.8 and 5.9. Struve 1270 (Σ1270) consists of a pair of stars, magnitudes 6.4 and 7.4.
The other main named star in Hydra is Sigma, σ, Hydrae, which also has the name of Minaruja, from the Arabic for snake's nose. At magnitude 4.54, it is rather dim. The head of the snake corresponds to the Āshleshā nakshatra, the lunar zodiacal constellation in Indian astronomy.
Hydra is also home to several variable starsR Hydrae is a Mira variable star 2000 light-years from Earth; it is one of the brightest Mira variables at its maximum of magnitude 3.5. It has a minimum magnitude of 10 and a period of 390 days. V Hydrae is an unusually vivid red variable star 20,000 light-years from Earth. It varies in magnitude from a minimum of 9.0 to a maximum of 6.6. Along with its notable color, V Hydrae is also home to at least two exoplanets.[2] U Hydrae is a semi-regular variable star with a deep red color, 528 light-years from Earth. It has a minimum magnitude of 6.6 and a maximum magnitude of 4.2; its period is 115 days.[1]
The constellation also contains the radio source Hydra A.

Deep-sky objects

Planetary nebula Abell 33 captured using ESO's Very Large Telescope.[3]
Elliptical galaxy called NGC 3923.[4]
Hydra contains three Messier objectsM83, also known as the Southern Pinwheel Galaxy, is located on the border of Hydra and CentaurusM68 is a globular cluster near M83, and M48 is an open star cluster in the western end of the serpent.[1]
NGC 3242 is a planetary nebula of magnitude 7.5, 1400 light-years from Earth.[5] Discovered in 1785 by William Herschel, it has earned the nickname "Ghost of Jupiter" because of its striking resemblance to the giant planet.[6] Its blue-green disk is visible in small telescopes and its halo is visible in larger instruments.[1]
M48 (NGC 2548) is an open cluster that is visible to the naked eye under dark skies. Its shape has been described as "triangular"; this 80-star cluster is unusually large, more than half a degree in diameter, larger than the diameter of the full Moon.[1]
There are several globular clusters in Hydra. M68 (NGC 4590) is a globular cluster visible in binoculars and resolvable in medium amateur telescopes. It is 31,000 light-years from Earth and of the 8th magnitude.[1] NGC 5694 is a globular cluster of magnitude 10.2, 105,000 light-years from Earth. Also called "Tombaugh's Globular Cluster", it is a Shapley class VII cluster; the classification indicates that it has intermediate concentration at its nucleus. Though it was discovered as a non-stellar object in 1784 by William Herschel, its status as a globular cluster was not ascertained until 1932, when Clyde Tombaugh looked at photographic plates taken of the region near Pi Hydrae on 12 May 1931.[8]
M83 (NGC 5236), the Southern Pinwheel Galaxy, is an 8th magnitude face-on spiral galaxy.[1] It is easily observed in skies south of 40°N latitude, found by using 123, and 4 Centauri as guide stars.[9] It has been host to six supernovae, more than any Messier object. Large amateur telescopes - above 12 inches aperture - reveal its spiral arms, bar, and small, bright nucleus.[1][9] In a medium-sized amateur instrument, around 8 inches in aperture, the spiral arms become visible under good conditions. It is not perfectly symmetrical in the eyepiece, rather, the northwest side is flattened and the nucleus has a southwest-to-northeast bar. A smaller sister to the Milky Way, it is a grand design spiral galaxy 40,000 light-years across.[9]
NGC 2865 is relatively youthful and dynamic, with a rapidly rotating disc full of young stars and metal-rich gas.[10]
There are many other galaxies located in Hydra. NGC 3314, usually delineated as NGC 3314a and NGC 3314b, is a pair of galaxies that appear superimposed, despite the fact that they are not related or interacting in any way. The foreground galaxy, NGC 3314a, is at a distance of 140 million light-years, and is a face-on spiral galaxy. The background galaxy, NGC 3314b, is an oblique spiral galaxy, and has a nucleus that appears reddened because of NGC 3314a's dusty disk.[11] ESO 510-G13 is a warped spiral galaxy located 150 million light-years from Earth. Though most galactic disks are flat because of their rate of rotation, their conformation can be changed, as is the case with this galaxy. Astronomers speculate that this is due to interactions with other galaxies.[12] NGC 5068 may be a member of the M83 group, but its identity is disputed. It has a low surface brightness and has a diameter of 4.5 arcminutes. It is not perfectly circular, rather, it is elliptical and oriented on a west-northwest/east-southeast axis. However, it is of fairly uniform brightness throughout.[13]

Meteor showers[edit]

The Sigma Hydrids peak on December 6 and are a very active shower with an unknown parent body.[14] The Alpha Hydrids are a minor shower that peaks between January 1 and 7.[15]

History and mythology

Western mythology

Hydra and surrounding constellations, from Urania's Mirror (1825).
The Greek constellation of Hydra is an adaptation of a Babylonian constellation: the MUL.APIN includes a "serpent" constellation (MUL.DINGIR.MUŠ) that loosely corresponds to Hydra. It is one of two Babylonian "serpent" constellations (the other being the origin of the Greek Serpens), a mythological hybrid of serpent, lion and bird.[16]
The shape of Hydra resembles a twisting snake, and features as such in some Greek myths. One myth associates it with a water snake that a crow served Apollo in a cup when it was sent to fetch water; Apollo saw through the fraud, and angrily cast the crow, cup, and snake, into the sky. It is also associated with the monster Hydra, with its many heads, killed by Hercules, represented in another constellation.[17] According to legend, if one of the hydra's heads was cut off, two more would grow in its place. However, Hercules burned out the roots of the heads he severed to prevent them from growing again, and thus overcame the hydra.[18]

Mythology and equivalents in other cultures

In Hindu Mythology the star that equivalents Hydra is Ashlesha.[19] In Chinese astronomy, the stars that correspond to Hydra are located within the Vermilion Bird and the Azure Dragon. In Japanese culture, the stars are known as Nuriko.[citation needed]



The text is in the public domain.

[image ALT: a blank space]

p246
Close by the Serpent spreads; whose winding Spires
With ordered stars resemble scaly Fires.
Creech's Manilius.
Hydra, the Water-snake,
is the French Hydre, the German Grosse Wasserschlange, and the Italian Idra, and may be classed among the Argonautic constellations, as it was said to represent the Dragon of Aetes.
p247Its stars are now well defined under this single title, but anciently were described, with their riders Corvus and Crater, as Ovid [Fasti, II.266] wrote:
Anguis, Avis, Crater, sidera juncta micant.
This continued to the 18th century, Flamsteed and other early astronomers making of them even four divisions, Hydra, Hydra et Crater, Hydra et Corvus, and Continuatio Hydrae. Nepa and Nepas, originally African words for the terrestrial crab and scorpion, seem also to have been used for this constellation in classic times.

Aratos called it Ὕδρη; Eratosthenes, Hipparchos, and Geminos, ῾Ύδρος, the Hydros of Germanicus, while others wrote it Ὕδρα; but Eratosthenes again had it all under Κόραξ, and Hipparchos also used Δράκων.

In Low Latin it has been Hidra, Idra, and Ydra; and, in the Almagest of 1551, Hydrus in the masculine, which, correct enough before Bayer's day, would now confound it with the new southern figure. Riccioli, and Hyde in his translation of Ulug Beg's catalogue, had it thus, showing its continuance till then as a common title, although often written Idrus and Idrus aquaticus, as well as changed to Serpens aquaticus.

Other names, also used for the northern Dragon, have been Draco, Asiua, and Asuia, or Asvia, which Bayer referred to as ἀσούγια non ἀσβία; but these are not Greek words, and doubtless are from Al Shujāʽ, the Snake, transformed, as only the late mediaeval astronomical writers and their immediate successors could transform classical and Arabic terms into their Low Latin and Greek; Chilmead wrote it Alsugahh. Still another conception and title may be seen in the Arabo-Latin Almagest's Stellatio Ydre: et est species serpentium; et jam nominatur Asiua. secur; where the last word, if an abbreviation for securis, "ax," seems not inappropriate when taking the western half of Hydra for a somewhat crooked handle, and Corvus for the ax-head. The Asina, or She Ass, which La Lande mentioned, is probably a continuation of some early type error in the barbarous Asiua.

Coluber, the Snake, and Echidna, the Viper, also obtain for Hydra, with the adjectives Furiosus, Magnanimus, and Sublimatus, here used as proper nouns, as they were for Orion. The Arabians similarly called it Al ayyah, another of their words for a snake, — El Havic in Riccioli'sNew Almagest.

Its representation has generally been as we have it, but the Hyginus of 1488 added a tree in whose branches the Hydra's head is resting; probably a recollection of the dragon that guarded the apple-trees of the Hesperides, although this duty really belonged to our Draco; and at times it has been shown as three-headed. Map-makers have always figured it in its present form, the Cup resting midway on its back, with the Raven peckingp248at one of its folds; Hydra preventing the latter's access to the Cup in punishment for its tattling about Coronis; or for its delay in Apollo's service. The minor constellation Turdus, or Noctua, only recently has been added to it.

Those who saw biblical symbols among the stars called Hydra the Flood; Corvus, Noah's Raven; and Crater, the Cup "out of which the patriarch sinned"; but Julius Schiller said that the whole represented the River Jordan.

The 7th sieu, Lieu, a Willow Branch, or Liu, a Circular Garland, — was the creature's head, 15° south of Praesaepe, δ being the determinant, and formed the beak of the Red Bird; it governed the planets and was worshiped at festivals of the summer solstice as an emblem of immortality.

Here, too, was the 7th nakshatra, Āçleshā, or Āçreshā, the Embracer, figured as a Wheel, with Sarpas, the Serpents, as presiding divinities;ε marking the junction with the nakshatra Maghā.

The 8th sieu, Sing, a Star, anciently Tah, was formed by ασ, and τ, with others smaller lying near them, α being the determinant. This asterism constituted the neck of the Red Bird, and, Edkins asserts, was also known as the Seven Stars.
The 9th sieu consisted of κυ1υ2λμφ, and another unascertained, and was called Chang or Tchang, a Drawn Bow, — Brown says "ancientlyTjung, the Archer," — υ1 being the determinant; the god Chang using this bow to slay the Sky Dog, our Crater. The stars between Corvus and Crater were Kien Mun, and those between γ Hydrae and Spica of the Virgin were Tien Mun, Heaven's Gate. These lie beyond the outlines of the Virgin's robe on the Heis map, but on Burritt's are included in the tip of her left wing.

Hydra is supposed to be the snake shown on a uranographic stone from the Euphrates, of 1200 B.C., "identified with the source of the fountains of the great deep," and one of the several sky symbols of the great dragon Tiāmat. Certain stars near, or perhaps in the tip of Hydra's tail and in Libra, seem to have been the Akkadian En‑te-na-mas‑luv, or En‑te-na-mas‑mur, the Assyrian Etsen-tsiri, the Tail-tip.

Theon said that the Egyptians considered it the sky representative of the Nile, and gave it their name for that river.

After Al Sufi's day, in our 10th century, the figure was much lengthened, and now stretches for nearly 95° in a winding course from Cancer to Scorpio; this well agreeing with the fable of its immense marine prototype, the Scandinavian Kraken. Conrad Gesner, the 16th‑century naturalist, gave an illustration of this in its apparently successful attack upon the ship Argo. p249The constellation cannot be seen in its entirety till Crater is on the meridian. Argelander enumerates in it 75 stars; Heis, 153.

For an unknown period its winding course symbolized that of the moon; hence the latter's nodes are called the Dragon's Head and Tail. When a comet was in them poison was thought to be scattered by it over the world; but these fanciful ideas are now associated with Draco.
Al Sufi mentioned an early Arab figure, Al ail, the Horse, formed from stars some of which now belong to our Hydra, but more to Leo andSextans.
The Water-serpent's gleaming bend.
Brown's Aratos.
α, 2, orange.
Alphard, Alfard, and Alpherd, — Alphart in the Alfonsine Tables and Pherd with Hyde, — are from Al Fard al Shujāʽ, the Solitary One in the Serpent, well describing its position in the sky. Caesius gave Alpharad, which on the Reuter wall-map was Alphrad; and a still more changed title is Alphora. The Arabs also knew α as Al Faār al Shujāʽ, the Backbone of the Serpent; but Ulug Beg changed this to Al ʽUnk al Shujāʽ, the Serpent's Neck; and its shared the Suhel of other bright stars as Suhel al Fard, and Suhel al Shām, the Solitary, and the Northern, Suhail.

Tycho first called it Cor Hydrae, the Hydra's Heart, — Riccioli's Kalb Elhavich and Kalbelaphard, — which, with the alternative Collum Hydrae, the Hydra's Neck, is current even now.

In China it determined the 8th sieu, and was the prominent star of the Red Bird that combined the seven lunar divisions of the southern quarter of the heavens. Its longitude is said to have been ascertained there in the 19th century before our era, but the statement may be questionable; as also it was observed passing the meridian at sunset on the day of the vernal equinox during the time of the emperor Yao, about 2350 B.C. It culminates on the 26th of March.

β and ξ were the Chinese Tsing Kew, the Green Hill.

δεζηρ, and σ, 3d to 5th magnitudes, on the head, were Ulug Beg's Min al Azʽal, Belonging to the Uninhabited Spot.

ε is a remarkable triple, — an 8th‑magnitude 3½ʺ from a 3.8‑magnitude, the latter divided by Schiaparelli, in 1892, into two of nearly equal brightness 0ʺ.2 apart, — which probably form a rapid ternary system.

ι, a 4th‑magnitude, was the Chinese Ping Sing, a Tranquil Star.

κ, a 5th‑magnitude, and the stars of about the same brilliancy extending from it to β, with β Crateris, were Al Sufi's Al Sharāsīf, the Ribs.

p250σ, 4.6, was Ulug Beg's Al Minar al Shujāʽ, the Snake's Nose.

τ1, 4.9, flushed white, and τ2, lilac, with ι and the 5th‑magnitude A, form the curve in the neck, Ptolemy's Καμπή; but Kazwini knew them asʽUdah, the Knot.






Hydra constellation map.svg
Por Hydra_constellation_map.png: Torsten Brongerderivative work: Kxx (talk) - Hydra_constellation_map.png, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=10840093



Os desenhos formados pelas estrelas 
- as constelações -
são como janelas que se abrem para a infinitude do universo 
e que possibilitam nossa mente a ir percebendo 
que existe mais, bem mais, 
entre o céu e a terra...  
bem como percebendo que o caos, 
vagarosamente, 
vai se tornando Cosmos 
e sendo por nossa mente conscientizado.  

Quer dizer, 
nossa mente é tão infinita quanto infinito é o Cosmos.

COM UM ABRAÇO ESTRELADO,
Janine Milward


VISITE MINHA PÁGINA
DA TERRA AO CÉU E AO INFINITO