the sharpless catalogue


Sh2-86

Sh2-86, also known as NGC 6820, is an emission nebula that surrounds the open cluster NGC 6823 in Vulpecula. The center of the open cluster is about two million years old and is predominantly represented by many young, bright blue stars. Outer parts of the cluster intimately involving pillars of emission nebula NGC 6820, contain even younger stars. The huge pillars of gas and dust are probably formed when surrounding gas and dust is pushed and eroded away by radiation from nearby stars. Open star cluster NGC 6823 is about 50 light years across and lies about 6,000 light years away. The center of the cluster formed about two million years ago and is dominated in brightness by a host of bright young blue stars. Outer parts of the cluster contain even younger stars. It forms the core of the Vulpecula OB1 stellar association.

(Source: Wikipedia)


Sh2-101

Sh2-101 is a H II region emission nebula located in the constellation Cygnus. It is sometimes also called the Tulip Nebula. It was catalogued by astronomer Stewart Sharpless in his 1959 catalog of nebulae. It lies at a distance of about 6,000 light years from Earth. Sh2-101, at least in the field seen from earth, is in close proximity to microquasar Cygnus X-1, site of one of the first suspected black holes. Cygnus X-1 is the brighter of the two stars (lower star) in close vertical proximity just to the right of Sh2-101 in the image presented here.

(Source: Wikipedia)


Sh2-103

Sh2-103 (Veil Nebula) is a cloud of heated and ionized gas and dust in the constellation Cygnus. It constitutes the visible portions of the Cygnus Loop, a large but relatively faint supernova remnant. The source supernova exploded circa 3,000 BC to 6,000 BC, and the remnants have since expanded to cover an area roughly 3 degrees in diameter. The Far Ultraviolet Spectroscopic Explorer (FUSE) data supports a distance of about 1,470 light years.

(Source: Wikipedia)


Sh2-105

Sh2-105 (Crescent Nebula) is an emission nebula in the constellation Cygnus, about 5,000 light years away from Earth. It was discovered by Friedrich Wilhelm Herschel in 1792. It is formed by the fast stellar wind from the Wolf-Rayet star WR 136 (HD 192163) colliding with and energizing the slower moving wind ejected by the star when it became a red giant around 250,000 to 400,000 years ago. The result of the collision is a shell and two shock waves, one moving outward and one moving inward. The inward moving shock wave heats the stellar wind to X-ray-emitting temperatures.

(Source: Wikipedia)


Sh2-108

Sh2-108 (IC 1318) is the diffuse emission nebula surrounding Sadr or γ Cygni. Sadr lies in the center of Cygnus's cross. The Sadr region is one of the surrounding nebulous regions. It contains many dark nebulae in addition to the emission diffuse nebulae. Shown here is a part of the Butterfly Nebula (part of the γ Cygni Nebula).

(Source: Wikipedia)


Sh2-117

Sh2-117 covers not only the North America Nebula (NGC 7000) and Pelican Nebula, but IC 5068 as well, which lies below them. The North America Nebula and the nearby Pelican Nebula are parts of the same interstellar cloud of ionized hydrogen (H II region). Between the Earth and the nebula complex lies a band of interstellar dust that absorbs the light of stars and nebulae behind it, and thereby determines the shape as we see it. The distance of the nebula complex is not precisely known, nor is the star responsible for ionizing the hydrogen so that it emits light. If the star inducing the ionization is Deneb, as some sources say, the nebula complex would be about 1,800 light years away, and its absolute size (6° apparent diameter on the sky) would be 100 light years. The nebula was discovered by William Herschel, from Slough, England, on October 24, 1786.

(Source: Wikipedia)


Sh2-131

Sh2-131, also known as IC 1396, is a large ionized gas region located in the constellation Cepheus about 2,400 light years away from Earth. The Elephant's Trunk Nebula is a dark, dense globule (IC 1396A) within this complex. The bright rim is the surface of the dense cloud that is being illuminated and ionized by a very bright, massive star (HD 206267) that is just to the east of IC 1396A. The entire IC 1396 region is ionized by the massive star, except for dense globules that can protect themselves from the star's harsh ultraviolet rays. The combined action of the light from the massive star ionizing and compressing the rim of the cloud, and the wind from the young stars shifting gas from the center outward lead to very high compression in the Elephant's Trunk nebula. This pressure has triggered the current generation of protostars.

(Source: Wikipedia)


Sh2-142

Sh2-142, also known as the Wizard Nebula, is an open cluster discovered by Caroline Herschel in 1787. William Herschel included his sister's discovery in his catalog, and labelled it H VIII.77. It is also known as NGC 7380. This reasonably large nebula is located in Cepheus. Located 7,200 light years away, the Wizard nebula, surrounds developing open star cluster NGC 7380. Visually, the interplay of stars, gas, and dust has created a shape that appears to some like a fictional medieval sorcerer. The active star forming region spans about 100 light years, making it appear larger than the angular extent of the Moon. Although the nebula may last only a few million years, some of the stars being formed may outlive our Sun.

(Source: Wikipedia)


Sh2-162

Sh2-162, also known as the Bubble Nebula, is a HII region emission nebula in the constellation Cassiopeia. It lies close to the direction of the open cluster Messier 52. The bubble is created by the stellar wind from a massive hot, 8.7 magnitude young central star, SAO 20575. The nebula is near a giant molecular cloud which contains the expansion of the bubble nebula while itself being excited by the hot central star, causing it to glow. It was discovered in 1787 by William Herschel. The star SAO 20575 is thought to have a mass of about 44 M.

(Source: Wikipedia)


Sh2-184

Sh2-184, also known as the Pacman Nebula (NGC 281), is a bright emission nebula and part of an H II region in the northern constellation of Cassiopeia and is part of the Milky Way's Perseus Spiral Arm. This nebulosity is also associated with open cluster IC 1590, several Bok globules and the multiple star, B 1. A recent distance from radio parallaxes of water masers at 22 GHz made during 2014 is estimated it lies 9,200 light years from us. E. E. Barnard discovered this nebula in August 1883, who described it as "a large faint nebula, very diffuse". Multiple star B 1 was later discovered by S. W. Burnham, whose bright component is identified as the highly luminous O6 spectral class star, HD 5005 or HIP 4121. It consists of an 8th magnitude primary with four companions at distances between 1.4 and 15.7 arcsec. There has been no appreciable change in this quintuple system since the first measures were made in 1875.

(Source: Wikipedia)


Sh2-190

Sh2-190, also known as the Heart Nebula (NGC 896, IC 1805), lies some 7,500 light years away from Earth and is located in the Perseus Arm of the Galaxy in the constellation Cassiopeia. It was discovered by William Herschel on 3 November 1787. This is an emission nebula showing glowing ionized hydrogen gas and darker dust lanes. The nebula's intense red output and its configuration are driven by the radiation emanating from a small group of stars near the nebula's center. This open cluster of stars known as Melotte 15 contains a few bright stars nearly 50 times the mass of our Sun, and many more dim stars that are only a fraction of our Sun's mass.

(Source: Wikipedia)


Sh2-199

Sh2-199, also known as the Soul Nebula (IC 1848), is an emission nebula located in Cassiopeia. The Soul Nebula houses several open clusters of stars, a large radio source known as W5, and huge evacuated bubbles formed by the winds of young massive stars. Located about 6,500 light years away, the Soul Nebula spans about 100 light years and is usually imaged next to its celestial neighbor the Heart Nebula (IC 1805).

(Source: Wikipedia)


Sh2-229

Sh2-229, also known as the Flaming Star Nebula, is an emission/reflection nebula in the constellation Auriga, surrounding the bluish star AE Aurigae. The nebula measures approximately 37.0' x 19.0', and lies about 1,500 light years away from Earth. It is believed that the proper motion of the central star can be traced back to the Orion's Belt area. The nebula is about 5 light years across.

(Source: Wikipedia)


Sh2-248

Sh2-248, also known as the Jellyfish Nebula and IC 443, is a Galactic supernova remnant in the constellation Gemini. On the plan of the sky, it is located near the star η Geminorum. Its distance is roughly 5,000 light years from Earth. IC 443 may be the remains of a supernova that occurred 3,000 - 30,000 years ago. The same supernova event likely created the neutron star CXOU J061705.3+222127, the collapsed remnant of the stellar core. IC 443 is one of the best-studied cases of supernova remnants interacting with surrounding molecular clouds.

(Source: Wikipedia)


Sh2-252

Sh2-252, also known as Monkey Head Nebula, is an H II emission nebula located in the constellation Orion and is associated with the open star cluster NGC 2175. It is thought to be located about 6,400 light years away from Earth. The nebula may have formed through hierarchical collapse. There is some equivocation in the use of the identifiers NGC 2174 and NGC 2175.

(Source: Wikipedia)


Sh2-273

Sh2-273 or NGC 2264 is the designation number that identifies two astronomical objects as a single object: the Cone Nebula and the Christmas Tree Cluster. Two other objects are within this designation but not officially included: the Snowflake Cluster and the Fox Fur Nebula. All of the objects are located in the Monoceros constellation and are located about 2,600 light years from Earth. NGC 2264 is sometimes referred to as the Christmas Tree Cluster and the Cone Nebula. However, the designation of NGC 2264 in the New General Catalogue refers to both objects and not the cluster alone. NGC2264 is the location where the Cone Nebula, The Stellar Snowflake Cluster and the Christmas Tree Cluster are all included in this emission nebula. The Stellar Snowflake Cluster is located 2,700 light years away in the constellation Monoceros. The Monoceros constellation is not typically visible by the naked eye due to its lack of colossal stars. The Snowflake Cluster was granted its name due to its unmistakeable pinwheel-like shape and its assortment of bright colors. The Christmas Tree star formation consists of young stars obscured by heavy layers of dust clouds.

(Source: Wikipedia)


Sh2-275

Sh2-275, the Rosette Nebula (also known as Caldwell 49) is a large spherical HII region (circular in appearance) located near one end of a giant molecular cloud in the Monoceros region of the Milky Way Galaxy. The open cluster NGC 2244 (Caldwell 50) is closely associated with the nebulosity, the stars of the cluster having been formed from the nebula's matter. The cluster and nebula lie at a distance of some 5,000 light years from Earth and measure roughly 130 light years in diameter. The radiation from the young stars excites the atoms in the nebula, causing them to emit radiation themselves producing the emission nebula we see. The mass of the nebula is estimated to be around 10,000 solar masses. A survey of the nebula with the Chandra X-ray Observatory has revealed the presence of numerous new-born stars inside optical Rosette Nebula and studded within a dense molecular cloud. Altogether, approximately 2,500 young stars lie in this star-forming complex, including the massive O-type stars HD 46223 and HD 46150, which are primarily responsible for blowing the ionized bubble. Most of the ongoing star-formation activity is occurring in the dense molecular cloud to the south east of the bubble. A diffuse X-ray glow is also seen between the stars in the bubble, which has been attributed to a super-hot plasma with temperatures ranging from 1 to 10 million K. This is significantly hotter than the 10,000 K plasmas seen in HII regions, and is likely attributed to the shock-heated winds from the massive O-type stars.

(Source: Wikipedia)