Nebula | |
---|---|
Observation data: J2000 epoch | |
Right ascension | 9h 0m 17s [1] |
Declination | −45° 54′ 57″ [1] |
Distance | 815 ly |
Apparent magnitude (V) | +12.0? |
Apparent dimensions (V) | 30'x7' |
Constellation | Vela [2] |
Physical characteristics | |
Radius | ~5.0 ly |
Designations | NGC 2736, Pencil Nebula |
NGC 2736 (also known as the Pencil Nebula) is a small part of the Vela Supernova Remnant, located near the Vela Pulsar in the constellation Vela. The nebula's linear appearance triggered its popular name. It resides about 815 light-years (250 parsecs) away from the Solar System. It is thought to be formed from part of the shock wave of the larger Vela Supernova Remnant. The Pencil Nebula is moving at roughly 644,000 kilometers per hour (400,000 miles per hour).
On 1 March 1835, John Herschel discovered this object at the Cape of Good Hope and described it as "eeF, L, vvmE; an extraordinary long narrow ray of excessively feeble light; position 19 ±. At least 20' long, extending much beyond the limits of the field...". This agrees perfectly with the ESO- Uppsala listing N2736 = E260-N14, a nebula with dimensions 30'x7', position angle of 20 and notes "Luminous filament". Harold Corwin adds that on the ESO IIIa-F film this nebula is the brightest patch of a huge supernova remnant (Gum Nebula) whose delicate whisps cover the field. A relatively bright star is immersed in N2736 (mentioned by Herschel). [3]
Vela is a constellation in the southern sky, which contains the Vela Supercluster. Its name is Latin for the sails of a ship, and it was originally part of a larger constellation, the ship Argo Navis, which was later divided into three parts, the others being Carina and Puppis. With an apparent magnitude of 1.8, its brightest star is the hot blue multiple star Gamma Velorum, one component of which is the brightest Wolf-Rayet star in the sky. Delta and Kappa Velorum, together with Epsilon and Iota Carinae, form the asterism known as the False Cross. 1.95-magnitude Delta is actually a triple or quintuple star system.
Messier 100 is a grand design intermediate spiral galaxy in the southern part of the mildly northern Coma Berenices. It is one of the brightest and largest galaxies in the Virgo Cluster and is approximately 55 million light-years from our galaxy, its diameter being 107,000 light years, and being about 60% as large. It was discovered by Pierre Méchain in 1781 and 29 days later seen again and entered by Charles Messier in his catalogue "of nebulae and star clusters".. It was one of the first spiral galaxies to be discovered, and was listed as one of fourteen spiral nebulae by Lord William Parsons of Rosse in 1850. NGC 4323 and NGC 4328 are satellite galaxies of M100; the former is connected with it by a bridge of luminous matter.
The Eagle Nebula is a young open cluster of stars in the constellation Serpens, discovered by Jean-Philippe de Cheseaux in 1745–46. Both the "Eagle" and the "Star Queen" refer to visual impressions of the dark silhouette near the center of the nebula, an area made famous as the "Pillars of Creation" imaged by the Hubble Space Telescope. The nebula contains several active star-forming gas and dust regions, including the aforementioned Pillars of Creation. The Eagle Nebula lies in the Sagittarius Arm of the Milky Way.
Centaurus A is a galaxy in the constellation of Centaurus. It was discovered in 1826 by Scottish astronomer James Dunlop from his home in Parramatta, in New South Wales, Australia. There is considerable debate in the literature regarding the galaxy's fundamental properties such as its Hubble type and distance. NGC 5128 is one of the closest radio galaxies to Earth, so its active galactic nucleus has been extensively studied by professional astronomers. The galaxy is also the fifth-brightest in the sky, making it an ideal amateur astronomy target. It is only visible from the southern hemisphere and low northern latitudes.
NGC 7331, also known as Caldwell 30, is an unbarred spiral galaxy about 40 million light-years (12 Mpc) away in the constellation Pegasus. It was discovered by William Herschel in 1784. NGC 7331 is the brightest galaxy in the field of a visual grouping known as the NGC 7331 Group of galaxies. In fact, the other members of the group, NGC 7335, 7336, 7337 and 7340, lie far in the background at distances of approximately 300-350 million light years.
The Cygnus Loop is a large supernova remnant (SNR) in the constellation Cygnus, an emission nebula measuring nearly 3° across. Some arcs of the loop, known collectively as the Veil Nebula or Cirrus Nebula, emit in the visible electromagnetic range. Radio, infrared, and X-ray images reveal the complete loop.
The Orion molecular cloud complex is a star-forming region with stellar ages ranging up to 12 Myr. Two giant molecular clouds are a part of it, Orion A and Orion B. The stars currently forming within the complex are located within these clouds. A number of other somewhat older stars no longer associated with the molecular gas are also part of the complex, most notably the Orion's Belt, as well as the dispersed population north of it. Near the head of Orion there is also a population of young stars that is centered on Meissa. The complex is between 1 000 and 1 400 light-years away, and hundreds of light-years across.
The Vela Pulsar is a radio, optical, X-ray- and gamma-emitting pulsar associated with the Vela Supernova Remnant in the constellation of Vela. Its parent Type II supernova exploded approximately 11,000–12,300 years ago.
The Vela supernova remnant is a supernova remnant in the southern constellation Vela. Its source Type II supernova exploded approximately 11,000 years ago. The association of the Vela supernova remnant with the Vela pulsar, made by astronomers at the University of Sydney in 1968, was direct observational evidence that supernovae form neutron stars.
NGC 246 is a planetary nebula in the constellation Cetus. It is the first known planetary nebula to have a hierarchical triple star system at its center. The nebula and the stars associated with it are listed in several catalogs, as summarized by the SIMBAD database. NGC 246 was discovered by William Herschel in 1785.
The Veil Nebula is a cloud of heated and ionized gas and dust in the constellation Cygnus.
The known history of supernova observation goes back to 1006 AD. All earlier proposals for supernova observations are speculations with many alternatives.
NGC 6334, colloquially known as the Cat's Paw Nebula, Bear Claw Nebula, or Gum 64, is an emission nebula and star-forming region located in the constellation Scorpius. NGC 6334 was discovered by astronomer John Herschel in 1837, who observed it from the Cape of Good Hope in South Africa. The nebula is located in the Carina–Sagittarius Arm of the Milky Way, at a distance of approximately 5.5 kilolight-years from the Sun.
NGC 2261 is a variable nebula located in the constellation Monoceros. The nebula is illuminated by the star R Monocerotis, which is not directly visible itself.
NGC 7252 is a peculiar galaxy resulting from an interaction between two galaxies that started a billion years ago. It is located 220 million light years away in the constellation Aquarius. It is also called Atoms for Peace Galaxy, a nickname which comes from its loop-like structure, made of stars, that resembles a diagram of an electron orbiting an atomic nucleus.
NGC 1187 is a barred spiral galaxy located about 60 million light-years away in the constellation of Eridanus. It was discovered on December 9, 1784 by the astronomer William Herschel.
NGC 134 is a barred spiral galaxy that resembles the Milky Way with its spiral arms loosely wrapped around a bright, bar-shaped central region. Its loosely bound spiral arms categorize it as Hubble-type Sbc. It is 60 million light years away, and part of the Sculptor constellation.
NGC 936 is a barred lenticular galaxy in the constellation Cetus. It is at a distance of about 60 million light-years away from Earth. Its nucleus and prominent bar have high surface brightness. Because of the shape of the prominent bar, the nucleus and the ring of stars at the end of the barrel, the galaxy has been compared with the shape of a TIE fighter, from the Star Wars universe, and thus NGC 936 has been named Darth Vader’s Galaxy or Darth Vader’s Starfighter. By measuring the radial velocity of the disc, Kormendy found in 1986 that the disc is stable, which is the reason why it is so smooth.
NGC 4490, also known as the Cocoon Galaxy, is a barred spiral galaxy in the constellation Canes Venatici. William Herschel discovered it in 1788. It is known to be of the closest interacting/merging galactic system. The galaxy lies at a distance of 25 million light years from Earth making it located in the local universe. It interacts with its smaller companion NGC 4485 and as a result is a starburst galaxy. NGC 4490 and NGC 4485 are collectively known in the Atlas of Peculiar Galaxies as Arp 269. The two galaxies has already made their closest approach and are rushing away from each other. It's been discovered that NGC 4490 has a double nucleus.