Aquilegia

History

This constellation is one of oldest which exists, perhaps oldest, in spite of its weak luminosity. Descriptions of a goat or a goat-fish were found on Babylonian shelves going back to 3 000 years. It is true that at that time, the Winter solstice took place when the Sun was there and this position of a Sun reappearing before its rise lasting spring probably contributed to its creation.

The Capricorn is usually drawn like a goat with cut in front. Some Greek identified it with Amalthée, the goat which nourishes Zeus at the time of its childhood. Others think that it represents Pan when he fled the monster Typhon. It had been transformed into goat and while wanting to plunge in water, it missed its transformation and only the back train became fish.

The Planet Neptune was discovered in this constellation by the German Astronome Johann Galle, close to Deneb Algedi (δ Cape), on September 23rd 1846.

Observation of stars

; Situation of the constellation The constellation is relatively easy to locate compared to great alignments:

It is located on the way (almost) right which leaves Large Ourse, passes by the heart of the Dragon and its head, to come to touch Véga of the Quadrant, then Altaïr. Véga alignment - Altaïr makes it possible to locate 20° more with the south α Capricorn and the two “feet” of the Capricorn 15° further. For the observers located sufficiently at the south, this alignment is prolonged to Al ir Na' (α Gruis), with an about sixty degrees of Altaïr.
In the other direction, the Capricorn is between PEGASE and the Verseau on a side, and the Sagittarius of the other, in an immense alignment which makes the turn of the sphere, and which is an axis of major location of the vault of heaven. On the basis of the Great square of PEGASE, this alignment passes by Algol, Capella, Castor and Pollux, Alphard (Hydre, the end of the Voiles then Acrux and Alpha Centauri, Shaula (λ Scorpii), the arc and the head (σ Sgr) of the Sagittarius, then goes up by the head of the Capricorne (β Cape), along the axis of the Verseau, to buckle on the diagonal of the Grand square of PEGASE.
Compared to the “headlights” of the area, the Capricorn is located about halfway between Véga of the Lyre and Fomalhaut of the southern Poisson.

; Form constellation The constellation of the Capricorn is the weakest constellation of the Zodiac after the Cancer. Its star S most brilliant is located about on a triangle having its tops in α, δ and ω Capricorni. Attention not to confuse this triangle with that formed by α Cape, β Aqr and ι Aqr, more in north and more visible.

the star easiest to locate is β Cape, located in the axis of the “head” of the Aigle. This star marks the “head” of the large goat, and a small neighbor 3° more with north, α Cape, marks the point of the horn.
In the alignment of these the first two stars, to 10° more in the south, one falls on a small pair from stars ψ and ω Cape, also with ~3° one of the other.
Perpendicular to this first direction, towards the east, one finds an alignment of four rather brilliant stars, which points a little in lower part of the “head”: θ, ι, γ, and finally δ Cape, most brilliant, which marks the end of the “tail”.

The “triangle” requires good conditions (mag 4) to be visible. When the conditions are excellent, one can guess underlinings of small intermediate stars which cut out this triangle in a “head” and a “body”. Compared to this cutting, α and β Cape rather appear the two horns of the Capricorn.

; Close constellations Towards the east, the limits with the Aquarius, itself weak and little structured, are not very obvious. The alignment which forms the “back” of Aquarius, in the axis of the diagonal of the Grand square of PEGASE, seems to be prolonged naturally until α Cape. Conversely, the “back” of the goat, alignment θ, ι, γ, and δ Cape (the “tail”), seem to finish naturally until.

Southern part, one sees with the feet of the Capricorn an appreciably East-West alignment, which points on Fomalhaut (in bottom on the left of the figure). Two stars in the axis Head - Shoes with 5° more in the south belong to the constellation (without interest) of the Microscope, the remainder of alignment towards the east belongs to the southern Poisson.

Principal stars

See also: List of stars of the Capricorn

Deneb Algedi (δ Capricorni)

Deneb Algedi ( the Tail of the Arab Child in ), δ Capricorni, is the most brilliant star of the constellation of the Capricorn. It is a white star, “metal” because its spectrum present of many traces of element S such as the Zinc, the Baryum, etc Its classification is not known exactly and it is thought that it is about a star in the last states of the principal sequence.

Deneb Algedi is a star doubles: it has a companion far from luminous (of Magnitude connect 15,8) who it eclipse every 1,023 days, lowering its own magnitude of 0,2. Taking into account time between two eclipses, the two stars are extremely close, perhaps even almost in contact. Deneb Algedi also has two other more remote companions, also far from luminous.

Dabih (β Capricorni)

Dabih (β Capricorni) is the 2nd star of the constellation. It is actually about an extremely complex stellar system. In first approach, it is about a double system. β^A Cape is most brilliant (magnitude 3,1). β^B Cape is just visible with the naked eye (magnitude 6,2). The two stars are distant from at least 21 000 ua and turn one around the other in at least 1 million years.

β^B Cape ( Dabih Minor ) is a supergéante (B9 class), abnormally enriched in mercury and Manganèse. It has itself a companion, distant from 30 ua, probably a standard star of class F, magnitude 13.

β^A Cape ( Dabih Major ) is more complex. Around it turns, in 3,8 years and with the distance from 4 ua, a giant star magnitude 9. But it also has another companion who orbits in only 8,7 days.

Algedi (α Capricorni)

Algedi (α Capricorni), “the Child” in Arabic, is the 3rd star of the constellation and owes its designation with its position, more in the west of stars of the Capricorn visible with the naked eye. Actually, Algedi is made up of two stars distinct, almost discernible with the naked eye (what in fact an almost single case among all the stars) and which do not have any bond between them strictly. Most distant (687 light-years), α¹ Cape, is the least brilliant (magnitude 4,75). Nearest (109 light-years, six times less further), α ² Cape, has a magnitude connect of 3,58. Both are dying yellow stars, α¹ Cape, also named PRIMA Giedi , is a supergéante of G3 class, α ² Cape, named Secunda Giedi , is a giantess of G8 class.

α¹ Cape is a multiple star. It has three companions, magnitude 9,6,14,1 and 14,2.

α ² Cape is also a multiple star. Two stars him Orbit NT around, on a very close orbit, each one magnitude lower than 11.

Other stars

The constellation of the Capricorn has two more other stars having of the proper names: Nashira (γ Capricorni) and Alshat (ν Capricorni).

Celestial objects

The constellation of the Capricorn shelters the Amas globular M30, magnitude 7,2, distant of 26 000 light-years.

See too

List of stars of the Capricorn

Zh-yue: 摩羯座

Random links:

James Schwarzenbach | Costa Faced | Al Yarmouk | Baja Destruction | Pierre Karl Péladeau