N 81 is a cloud of reddening gas, which shelters from young and brilliant stud. The reddish glow of this nebula is the result of the ultraviolet radiation emitted by its most brilliant two stars, 300 000 times as brilliant as the Sun. N 81 is in the Small Cloud of Magellan, itself small satellite galaxy of the Milky Way. The recent and massive stars inside N 81 lose their matter very quickly, creating powerful solar winds and shock waves drilling the cocoon of the outside nebula. The most brilliant both stars seen on the image of Hubble under the shape of a pair very moved closer near the center of N 81 emit strong ultraviolet radiations, returning the fluorescent nebula.

ESO: photo realized on December 21st, 2006

The nebula is situated in the approximately 2000 years light of the Earth in the direction of the constellation of the Unicorn. It is the last moments of the spectacular system of binary stars that we see on the photo opposite in the center of the nebula. These two stars are so close as they orbit the one around the other one in 16 days. Even with Hubble, the pair of stars cannot be seen as two separate constituents. The astronomers think that one of the stars, by evolving developed to become a red giant and literally absorbed her companion.

Stars swirled together in spirals, and most of the external layers of the red giant were ejected in a dense disk which surrounds now the central star. The nebula is also rich in clouds of dust, among which some form of long streak sink who point far from the central star. The spatial telescope Hubble arrested this image of the nebula in shape "of wing of butterfly", NGC on 2346.

La nébuleuse du papillon vue par Hubble

The nebula of the Head of Horse (officially known under the name of Barnard 33; IC434 is a dark nebula in the constellation of Orion. The nebula is just below Alnitak (ζ Ori), the star most east of the belt of Orion. This nebula, situated in 1500 light years was discovered for the first time in 1888 on a photographic plate taken in the look-out observatory of Harvard College. It is easily recognizable by the shape at the head of horse which gave it its name. Indeed, behind the nebula is some hydrogen which, ionized by the brilliant star close Sigma Orionis, gives a red color.

The nebula of the head of horse

The nebula of the Hull is cataloged under the reference NGC 3372, it covers approximately three degrees of the sky at the distance of 8800 years light, what corresponds to a diameter of 460 years light. She can be observed in the bare eye. It is the region HII We call regions HII, nebulas to emission constituted by clouds mainly consisted of hydrogen and with which most of the atoms are ionized, and sometimes extending over several light years. The ionization is produced by the nearness of one or several very warm stars, spectral type O or B, which shine strongly in the extreme ultraviolet ray, so ionizing the gas surrounding, from which these stars originally formed.  (region of ionized hydrogen) the most brilliant of the Milky Way. Its angular diameter exceeds 4° on photography. The small said dark nebula of the " Hole of lock ( Keyhole) " (the cloud absorbing in the center of the nebula) juxtaposes on the most brilliant part of the nebula where the star a hour Carinae nests there.

M17 is a nebula in emission discovered by Cheseaux in 1746 then rediscovered by Messier in 1764 situated in the Sagittarius. Also known under the names of nebula Omega, the Swan, the Horseshoe, or the Lobster, this very brilliant nebula, about the pinkish colors, is visible in the bare eye under the low latitudes (magnitude is similar 6). This is of for the fact that it shelters young stars arisen from the nebula and which irradiate the gas surrounding, so creating a region HII We call regions HII, nebulas to emission constituted by clouds mainly consisted of hydrogen and with which most of the atoms are ionized, and sometimes extending over several light years. The ionization is produced by the nearness of one or several very warm stars, spectral type O or B, which shine strongly in the extreme ultraviolet ray, so ionizing the gas surrounding, from which these stars originally formed. , a red color of the nebula is moreover that some ionized hydrogen. In infrared, we were able to observe an important quantity of dusts, favorable to the formations of stars there.

The nebula of the horseshoe

Pleiads, or heap M45, are a heap opened by stars which observes in the north hemisphere, in the constellation of the Taurus.
The origin of the name "Pleiads" results from the Greek mythology: Pleiads are seven sisters, girls of Atlas and Pleione: Asterope, Merope (or Dryope, or Aero), Électre, Maïa, Taygete, Celaeno (or Selene) and Alcyone. We count approximately 500 stars today composing this heap, a dozen of which is visible in the bare eye. It extends over 2 °, is the

equivalent of 4 times the visible diameter of the Moon. its density is thus relatively weak with regard to the others heap opened. The age of the heap is estimated at 100 million years, but he should not live for a long time because he should part in 250 million years, partially because of his weak density.

Nebula of pleiads

Nebula of the eagle or M16.
The image opposite combines three colors emitted specifically and was taken by the telescope of 0,9 m of Kitt Peak, in Arizona, in the USA.

M57 is among objects the most known for the catalog Messier. It was discovered in 1779 by Darquier. It is an annular nebula which looks like the nebula Helix a lot. The real diameter of the ring is 1,3 al, is about a visible diameter 2 min of bow. The visible ring consists of oxygen and nitrogen ionized. The outside edge of the ring consists as for him of hydrogen. The dark part inside the ring is made by helium, and emits in the ultraviolet ray. M57 is often named Misty of the Ring, Nebula of the Lyre or simply The Lyre, the name that she pulls of her constellation host. A global nebula is a fine disk, in the irregular forms and in the luxurious colors. We so called up them, because seen in a small instrument, in the debuts of the observations, they appeared as weak planets. They appear as a nebula of

small angular dimensions, often very symmetric circular shape and bounded well, by opposition at the diffuse nebulas which seem to dilute in the space and of irregular shape. Numerous global nebulas have a shape of ring, as the ring of the Lyre, opposite. They show a density of matter stronger in suburb than inside. A star is always in the center. At the end of life, when they exhausted their hydrogen, stars see their peripheral layers dilating and cooling, whereas the heart collapses and warms up to reach the melting point of the helium. Certain stars go as far as ejecting their peripheral layers creating an expanding cocoon. The heart put in nude is a star of type W or O which shines a lot of ultraviolet light and which incites the nebula.
Nebula planetary of the Lyre or M57 image Hubble

In 1764, the French astronomer Charles Messier described this magnificent cloud cosmic as an oval nebula without star. Cataloged under the name of M 27, it is now known under the name of Nebula Dumbbell ("barbell" in English) because of its lengthened shape, what the eyes of Messier had noticed. This deep image of brilliant misty global reveal the central star of Dumbbell and a network of stars of front and back plan in the pinkish constellation of the Fox (Vulpecula in Latin). The dissimilar image adds up 8 hours of pose through a filter intended to record only the light resulting from atoms

of hydrogen, drawing the structure of the weak outside halo of the nebula which extends over light years. The Nebula Dumbbell, is a nebula similar to the fact that will happen our Sun when it will have exhausted its nuclear fuel. The central star (at the origin of the nebula) has a visible magnitude of 13,5, what makes it with difficulty observable for an amateur astronomer. It is a dwarf white with very warm blue color (85 000K). It is accompanied with another stud, even weaker (magnitude 17).
Nebula planetary Dumbell ou M57

The nebula of the Cone or the Christmas tree looks like a creature of nightmare, it is really a heap of gas and dusts, situated in 2500 light years of us in the Constellation of the Unicorn. NGC 2264 is a finger of dark matter pointing towards a group of stars. We are here in front of the visible part of a gigantic cloud of dense and opaque interstellar matter, consisted of dust and hydrogen. This nebula has the peculiarity to be for a variable brightness because of the star which illuminates the cloud and which varies in a irregular way.

Nebula of the Cone or NGC 2264
Image taken by Hubble in April, 2002. NASA, H. Ford (JHU), G. Illingworth (UCSC/LO), M. Clampin (STScI), G. Hartig (STScI), the ACS Science Team and ESA.

The nebula NGC 7000 reminds that of the American continent, where from its name.
 

To the naked eye, the light of the heap is dominated by a red global light which is provoked by the brilliant gaseous hydrogen, whereas dark strands result from the absorption by dense bands of dust. The image opposite, taken by the telescope Curtis-Schmidt, show the nebula in emission in three precise colors emitted specifically by the hydrogen, the oxygen and the sulfur. The Nebula of the Lagoon is situated in approximately 5000 light years of the Earth in the constellation of the Sagittarius. The nebula covers a region furthermore with three times the diameter of the Full moon.

The nebula lagoon or NGC 6523 or M8

Nebula NGC 1893

stud with the heap are visible just below the vast dark cloud of dust close to the center of the image. Within 7 hours of this sight with big field detailed well, we notice two relatively dense currents of matter seeming to pass by central regions of the nebula. Possible places of formation of stars, these cosmic tadpoles measure about 10 light years of length.
The nebula NGC 1893 or IC 410