vineri, 18 februarie 2011
duminică, 13 februarie 2011
One of the most identifiable nebulae in the sky, it is part of a swirling cloud of dark dust and gases, shaped like a horse's head (hence its name). Also known as Barnard 33, the unusual shape was first discovered in 1888 on a photographic plate taken at the Harvard College Observatory.
The red glow originates from hydrogen gas predominantly behind the nebula, ionized by the nearby bright star Sigma Orionis. The darkness of the Horsehead is caused mostly by thick dust, although the lower part of the Horsehead's neck casts a shadow to the left. Streams of gas leaving the nebula are funneled by a strong magnetic field. Bright spots in the Horsehead Nebula's base are young stars just in the process of forming.
The Cone Nebula (also known as NGC 2264) is an H II region in the constellation of Monoceros. It was discovered by William Herschel in 1785. The nebula is located about 800 parsecs or 2,600 light-years away from Earth.
The Cone Nebula is part of the nebulosity surrounding the Christmas Tree Cluster. The designation of NGC 2264 in the New General Catalogue refers to both objects and not the nebula alone.
Planetary Nebula M57 (also known as the Ring Nebula, NGC 6720 or Messier Object 57) is located in the constellation Lyra. It is among the most well known and recognizable examples of a planetary nebula. The nebula is located at 0.7 kpc(2300 light-years) from Earth and was discovered by Antoine Darquier de Pellepoix in 1779. The nebula has a visual magnitude of 8.8, and a photographic magnitude of 9.7. It is expanding at a rate of approximately 1 arcsecond per century (corresponding to 20-30 km/s). Its mass is approximately 1.2 solar mass.
M57 is illuminated by a central white dwarf of 14.7 visual magnitude. This star was discovered in 1800 by Count Friedrich von Hahn.
M57 is best seen through at least an 8-inch telescope, but even a 3-inch telescope will show the ring.
Right Ascention 18:53 Declination 33.02.
I've amde this 50X70 tempera painting of Ring Nebula when I was in highschool
The Boomerang Nebula was photographed in detail by the Hubble Space Telescope in 1998. It is believed that the nebula is a star or stellar system evolving toward the planetary nebula phase.
Keith Taylor and Mike Scarrott called it the Boomerang Nebula in 1980 after observing it with a large ground-based telescope in Australia. Unable to see the detail that only Hubble can reveal, the astronomers saw merely a slight asymmetry in the nebula's lobes suggesting a curved shape like a boomerang. The high-resolution Hubble images indicate that 'the Bow tie Nebula' would perhaps have been a better name.
To make it more interesting i made some boomerang UFOs in this painting.