Constellation Chart

The Swan

The constellation of Cygnus, The Swan, is seen in about zenith at northern hemisphere, and is one of most obvious asterisms in summer skies, which because of its shape is known as the Northern Cross. Alpha Cygni that marks the tail of swan is called Deneb, from "Al Dhanab al Dajajah" meaning of the Hen's tail. The star forms "The Great Summer's Triangle" with Altair (alpha Aquilae) and Vega (alpha Lyrae), and Deneb has the lowest magnitude in the trio, because of the star has the farthest distance of 1500 light years in bright stars with the first magnitude in heavens. Deneb is considered as a white supergiant. And beta Cygni positioned at the head of swan is also known as "Albireo", a magnificent binary system of gold and blue. The component is quite wide, marking it a popular object for binoculars.

Galaxies In Cygnus

NGC7000

NGC7000 is called "The North American Nebula" because of its shape. It's a bright emission nebula at about 3 degrees east of Deneb, alpha Cygni. The nebula is very photographed and attractive on long-exposure. Unfortunately you'll find it is extremely faint with a slightly greenish color. It's best seen in binoculars. The North American Nebula has very interesting shape by chance, and you can find one more unique shaped nebula of IC5067-70 just west of NGC7000. It has a nickname of " The Pelican Nebula".

IC1318

A central star in this picture is gamma Cygni (Sadr), and the star has been surrounded by the faint red nebula spread out like snatches of clouds. The nebula can hardly be detected with normal vision, but very photographed. It's the deepest region just east (left-hand side) of Sadr, clearly recognized that is tangled with dark nebulae.

IC5146

IC5146 is a small round reflection nebula near a border to Cepheus, with a size of 12 arc minutes. A nickname of "The Cocoon Nebula" has came from its round shape and dimmed impression. A dark filament of B168 is stretched westward from the cocoon nebula itself, and it seemingly looks like that the nebula is drifting in the Milky Way, very humorous view. The nebula is estimated about 5500 light years away.

I've captured the field of the part of swan's tail soaked in the summer's Milky Way around the zenith by using of a medium ranged telephoto lens. You can identify three popular emission nebulae in this picture, the North American Nebula around the center, IC1318 surrounding gamma Cygni at the right-hand side, and the Veil Nebula at the edge of lower side, respectively. These attractive red clouds in the Milky Way are emitting by neighbored stars.

IC 5076

IC 5076, NGC 1432, and the nebulosity are illuminated by 17 Tauri are reported. These observations are corrected for instrumentally scattered light and for variable sky background contamination. Similar observations of a fourth nebula Cederblad 201, are also discussed. Techniques for modelling the surface brightness distributions of nebulae are discussed, including two models for the nebula IC 5076. Using relatively well known grain properties at visible wavelengths, the geometry of each object and its ultraviolet brightness distributions are investigated.

NGC6992

Veil Nebula is a faint and vast loop spread at the south wing of swan, consists of east (NGC6992-5) and west (NGC6960) segments. They are fine filaments seemingly suspended in the space. East Side is brighter, and can be seen with binoculars in perfect conditions. The star 52 Cygni is in the same field as the western part, and a dimmed and vast cloud is spread between these two without being registered in any catalogues. It's considered that the nebula is a remnant of supernova exploded over ten thousand years ago, and is expanding outward with a velocity of about 100km (62 miles) per second. This elusive nebula has a real size of about 50 light years and a distance of 1300 light years.

NGC6826

NGC6826 is a small planetary nebula about 1.3 degrees east of theta Cygni, a tip star of Swan's western wing. The nebula has a diameter of 30 arc seconds and a visual brightness of 9th magnitude. The nebula looks almost oval figure and dimmed light is surrounding the central star. NGC6826 has a nickname of "The Blinking Plantary" maybe from its figure looks like an eye. You can distinguish the nebula from normal stars only with small telescopes, but it might be needed fairly larger scopes and high magnifying power to detect the central dwarf star. It's estimated the nebula is about 1700 light years away.

NGC6888

You can see a compact semicircular diffused nebula in this picture. The nebula of NGC6888 has a nickname of "The Crescent Nebula", positioned about 6 degrees southwest of gamma Cygni (Sadr). At around this field, very fine diffused nebula of IC1318 is floating and surrounding gamma Cyg. Actually, NGC6888 is part of IC1318, but the nebula is sufficiently bright by comparing with the nebulae in circumference, NGC6888 is noticeable in long-exposed films.

M29

M29 is a small open cluster found at about 2 degrees south of Sadr, gamma Cygni. The cluster is fairly modest for registered in the Messier's catalogue; not suitable for binoculars. You can detect four bright stars forming a tiny rectangle and some other members are surrounding with a magnifying power of about 30 or so. Actually, this field has a fine gaseous region of IC1318, and a fluffy nebula surrounds M29 itself.

M39

M39 is an open cluster about 7 degrees north-east of North American Nebula (NGC7000). You can find the cluster just in the Milky Way between the tail of Cygnus and Cassiopeia, there are plenty of faint stars that form the autumnal Milky Way around this field. M39 is large and scattered, telescope is unsuitable for appreciating that, and you should need a small binocular. About 20 faint stars with about 7th magnitude are forming a rough triangle. The cluster is about 810 light years away.

S106

Subaru Telescope has successfully taken a sharp and deep infrared image of the star-forming region, S106. In addition, many objects with masses less than that of an ordinary star have been discovered in this region.

S106 is at a distance of approximately 2000 light-years from the Earth. There is a large massive star called IRS4 (Infrared Source 4) at the center of S106. The star is approximately one hundred thousand years old, and its mass is approximately 20 times that of the Sun. The hourglass appearance of S106 is thought to be the result of the way material is flowing outwards from the central star. A huge disk of gas and dust surrounding IRS4 produces the constriction at the center.

Ultraviolet rays emitted from IRS4 ionize the surrounding hydrogen gas, creating what astronomers call an HII region. As the excited hydrogen gas relaxes, it emits the blue glow we see in the inner part of the nebula. We call this an emission nebula. The red region towards the edge of the nebula is a reflection nebula, made as surrounding dust particles directly reflect the light emitted from IRS4. Since this infrared image is extremely sharp, we can see subtle details like ripples inside the emission nebula. Furthermore, the differences in color and structure between the emission and reflection nebulae are beautifully displayed. In comparison, a visible-light image of the same region taken with the Hubble Space Telescope barely shows any detail in the upper part of the nebula because visible light is strongly absorbed by the region's dust.

A study of this deep S106 image has revealed hundreds of faint young objects around IRS4 and throughout the surrounding nebula. The mass of these objects is less than 0.08 times that of our Sun, too small to sustain the nuclear burning of hydrogen gas that causes a normal star to shine. They are considered to be young brown dwarfs.

The lightest and faintest objects discovered have an estimated mass of only a few times that of Jupiter. A joint group of astronomers from the National Astronomical Observatory of Japan and the University of Tokyo have observed similar light objects elsewhere in the sky, in the nearby star-forming regions towards the constellation of Taurus and Chameleon. Other researchers have seen such objects in the constellation of Orion. While such objects would be called "planets" if they orbited a star, this is not appropriate for these independent objects. For this reason, we would refer to them as "floating small objects."

From the observation with Subaru Telescope, it's clear that many light objects are born out in space along with the ordinary stars we see, and that the relative number of such objects differs from place to place. But the birth mechanism for these objects is still unclear.

Planetary Destinations In Cygnus

Gliese 777A B is more like our own system's Jupiter than any other planet so far discovered. It was the first giant planet of Jupiter mass discovered orbiting more than 3 AU from a sun-like star without any closer giant companions. This makes the Gliese 777A a prime hunting ground for earth mass planets closer in. Unlike the legions of Hot Jupiters and eccentric planets found around other stars, this planet reminds us of home.

Gliese 777A

Gliese 777A planetary System

Parent Star: Gliese 777A (G6 IV+) in the constellation of Cygnus is located at a distance of 51.86 Light Years from our Solar system. Co-ordinates of Right Ascension: 20 03 37.4055 & 29 53 48.500. The apparent Magnitude of the star is 5.71. The Inner Edge of Habitability Zone is 0.52 AU & the Outer Edge of Habitability Zone: 1.64 AU and the estimated stellar lifespan of the star is 13717 million years. Orbiting around Gliese 777A are planets Gliese 777A c, Gliese 777A b. Alternate Designations: HD 190360A.

Gliese 777A cthe planet is believed to be a Clarified Neptunian and its existence has been confirmed. The planets appearance is Blue and cloudless. The planet is positioned out side of Habitability Zone at Mean Orbital Distance of 0.128 AU and the estimated radius of the planet is 0.057 Jupiters. The planet Orbits around the star every 17.1 Days and was discovered by VOGT S., BUTLER P., MARCY G., FISCHER D., HENRY G., LAUGHLIN G., WRIGHT J. & JOHNSON A in 2005.

Gliese 777A bthe planet is believed to be a Ammonia Cloud Jovian, Eccentric and its existence has been confirmed. The planets appearance is White ammonia and water ice clouds, brown hydrocarbon stains. The planet is positioned out side of Habitability Zone at Mean Orbital Distance of 4.8 AU and the estimated radius of the planet is 1.33 Jupiters. The planet Orbits around the star every 3902 Days and was discovered by M. Mayor, D. Naef, F. Pepe, D. Queloz, N.C. Santos, S. Udry on 18 Jun 2002.

HD 187123

Parent Star: HD 187123 (G5) in the constellation of Cygnus is located at a distance of 163.2 Light Years from our Solar system Co-ordinates are Right Ascension: 19 46 57.45 & Declination: +34 25 15.8. The apparent Magnitude of the star is 7.9. The Inner Edge of Habitability Zone is 0.62 AU & the Outer Edge of Habitability Zone: 1.94 AU. Orbiting around HD 187123 is planet HD 187123 b is believed to be a Cloudy Hot Jupiter and its exitence has been confirmed. The Planets Appearance is Silicate clouds over dark sodium haze. The planet is positioned out side of Habitability Zone at Mean Orbital Distance of 0.042 AU. The planet Orbits around the star every 3.097 Days and was discovered by G. Marcy et al in 1998.

HD 187123 appears similar to the Sun in mass, age, chromosphere, and rotation rate. Although unlikely, non-Keplerian explanations for the Doppler variations, such as spots and pulsation, cannot be ruled out and require future photometry and spectroscopy

16 Cygni B

Parent Star: 16 Cygni B (G2.5 V) in the constellation of Cygnus is located at a distance of 85 Light Years from our Solar system Co-ordinates are Right Ascension: 19 41 51.8 & Declination: 50 31 03. The apparent Magnitude of the star is 6.2. The Inner Edge of Habitability Zone is 0.58 AU & the Outer Edge of Habitability Zone: 1.82 AU. Orbiting around 16 Cygni B is planet 16 Cygni B b is believed to be a water cloud jovian, eccentric and its exitence has been confirmed. The Planets Appearance is white water ice clouds . Planet at outer edge of habitability zone at mean orbital distance of 1.67 AU. The planet Orbits around the star every 798.938 Days and was discovered by Marcy and Butler and (separately) Cochran and Hatzes in 1996. Alternate Designations: HD 186427, HR 7504, HD 186427,

HD 188753 is a triple star system consisting of a K and an M class star orbiting each other, with the pair in turn orbiting a G class primary. The pair orbit the primary at an average distance of 12.3 AU, although the orbit has a high eccentricity bringing the pair as close as 6.2 AU and as far as 18.5 AU. The pair have a combined mass of 1.63 solar masses and are separated from each other by an average of 0.66 AU. The pair take 25.7 years to orbit the primary and 156 days to orbit each other.

HD 188753 A

Parent Star: HD 188753 A (Spectral Type: G) in the constellation of Cygnus is located at a distance of 149 Light Years from our Solar system Co-ordinates are Right Ascension: 19 54 58.37 & Declination: +41 52 17.5. The apparent Magnitude of the star is 7.43. The Inner Edge of Habitability Zone is 0.63 AU & the Outer Edge of Habitability Zone: 1.97 AU. Orbiting around HD 188753 A are HD 188753 Ab (Dark Hot Jupiter), HD 188753 c (Red Dwarf Star Companion of HD 188753 A), HD 188753 b (Orange Main Sequence Star Companion of HD 188753 A).

HD 188753 Ab is the first planet discovered in a triple star system. The HD 188753 system is made up of a G class primary orbited at an average distance of 12.3 AU by a pair of stars, class K and M, which orbit each other at a distance of 0.66 AU. The planet itself is a Hot Jupiter somewhat more massive than Jupiter itself. The existence of a planet in this system challenges prevailing planet formation models. Current theory suggests that gas giant planets form multiple AU from their central stars. Once formed, some of these planets may migrate close to their stars due to interactions with the protoplanetary disk. Such planets become Hot Jupiters.

The issue with HD 188753 is that its protoplanetary disk would have been truncated at about 1.3 AU from the primary star by the presence of the pair of secondary stars. A gas giant should not have been able to form so close to the primary, and with no disk material beyond 1.3 AU, a planet should not have been able to form beyond that distance to migrate inward. So how did HD 188753 Ab form?

One possibility is that the planet may have formed before the stars had reached their current configuration. Perhaps the pair were once more distant than they are now. Or perhaps the planet was captured somehow.

HD 188753 Ab is believed to be a Dark Hot Jupiter and its exitence has been confirmed. The Planets Appearance is Dark sodium haze. The planet is positioned out side of Habitability Zone at Mean Orbital Distance of 0.044 ± 0.001 AU. The planet Orbits around the star every 3.3481 ± 0.0009 Days and was discovered by Maciej Konacki et al in 2005.

HD 188753 c is a Red Dwarf Star Companion of HD 188753 A and is located at a distance of 149 Light Years from our Solar system Co-ordinates are Right Ascension: 19 54 58.37 & Declination: +41 52 17.5. Spectral Type: M, Primary Star: HD 188753 A (G) The Distance from the Primary star: 12.3 AU & Orbital Eccentricity is 0.5.

HD 188753 b is a Orange Main Sequence Star Companion of HD 188753 A and is located at a distance of 149 Light Years from our Solar system Co-ordinates are Right Ascension: 19 54 58.37 & Declination: +41 52 17.5. Spectral Type: K Primary Star: HD 188753 A (G) The Distance from the Primary star: 12.3 AU & Orbital Eccentricity is 0.5.