A highly conspicuous constellation, Cepheus is easy to find as it faces the W of Cassiopeia and is also found above Cygnus. It represents the husband of Cassiopeia and is aptly adjacent to Cassiopeia. The shape of the pattern of stars is reminiscent of a house with a pointy roof and this roof can be used to locate Polarus, the Pole Star. The constellation adorns the sky throughout most of the year and it contains a wealth of awesome nebulae and spiral galaxies.
Cepheus is home to a special class of variable stars, the Cepheids. Cepheids are used to measure distances and they were one of the factors in determining the distance to the Andromeda Galaxy by Edwin Hubble in the 1920's.
|The Iris Nebula is a cosmic flower that lies at a distance of 1500 light years and is embedded in a cloud of dust.
The delicate pastel hues form a truly unforgettable spectacle that wouldn't exist without the presence of the bright 7th magnitude central star.
|Image copyright D. Goldman|
|IC 1396 and Elephant Trunk Nebula:|
IC 1396 is a gigantic emission nebula whose angular size is so large that it is 6 times bigger than the Moon. The star that would have to illuminate a nebula of this size would also have to fairly massive and this is the case, it is a class O6 blue giant and is part of the Cepheus OB association.
The whole nebula can be glimpsed under dark skies with the naked eye south of the red giant Mu Cephei, which is popularly known as the Garnet Star. Because of its large size, it is difficult to view the whole nebula in the biggest telescopes. In fact, what is seen with the eye is actually the central star cluster Trumpler 37, the nebulosity is far too dim to be detected without any optical aid. The star cluster explodes into detail with a small telescope and it contains at least 50 stars. Most of the nebula complex is obscured by dark venomous looking patches that have their own separate designations in the Barnard dark nebula catalogue.
In the middle of the right half, lies the snaking dark glowing form of the Elephant Trunk Nebula. This is invisible to the naked eye and requires a telescope to be seen. It is one of the few bright rimmed globules and factors in creating these are hot stars and cold gas. The globule faces a bright OB star and it ionizes cold gas at the edge of the globule and this in turn glows while the rest remains dark. The Elephant Trunk Nebula is commonly designated as vdB142, this however is incorrect as the catalogue number refers to a miniscule reflection nebula towards the left of the globule, this can only be seen photographically.
|Iris Nebula (NGC 7023):|
Sprouting its petals into the cold heart of the surrounding darkness, this reflection nebula is a heavenly sight. Looking like an eye made by a celestial sculptor out of lapis lazuli and turquoise marble, this multi hued cloud resembles many things including an iris flower and in some instances, an eye. The name fortunately fits both things that it resembles.
The entire nebula is lit by the energy from one single star at the centre. The gas and dust before the star was born was part of the main dusty complex and the star transformed the dull brown shades into glorious magentas and azure blue colours, which contrast beautifully with the remaining dust. In widefield images, there appears to be a column of dust reaching downwards from the main reflection nebula and this could be considered to be the stem of this galactic flower. The nebula is also known as vdB139.
In a constellation dominated by nebulae, it is surprising to find a spiral galaxy. This particular galaxy seems to embody stellar death as there has been a high rate of supernovae explosions. There have been eight supernovae since 1917 and this might suggest that this galaxy has many generations of stars. The last supernova in our galaxy was in 1604.
NGC 6946 is almost a galactic neighbour at a short distance of 10 million light years, which is very close for a galaxy. It has four large spiral arms spliced with dust lanes and sprinkled with HII regions. The most southern spiral arm has an enormous blue blob, a collection of multiple star clusters. This could easily be mistaken for a single super star cluster but this galaxy has been analysed in detail due to its closeness.
This spiral galaxy is similar to IC 342 in the respect that it has low galactic latitude and is obscured by foreground dust in the Milky Way. It is also catalogued as Arp 29.
|Five billion years is the immense age of this ancient open star cluster. It was discovered in 1831 by John Herschel, son of the discoverer of planet Uranus. The total count of the number of stars is 120, which is surprising considering it's age although many stars must have died in the past. The main star type are yellow giants.|
|One of the sparse number of planetary nebulae in Cepheus, this intriguing planetary isn't well known but deserves to be. It consists of a round pink circle with lobes coming off opposite sides. The middle is a interweaving lattice of electrifying nebulosity wrapped around the penetrating glare of a magnitude 11 central star. Some observers call this the Bow Tie Nebula, the view through a small telescope shows the brightest parts of the nebula and they resemble the namesake. The resemblance is lost in photographs as the fainter parts are visible.|
|NGC 7380 and Sh2-142 :|
This gorgeous panoply of stars and vivacious pink nebulosity lies at an immense distance of 10 000 light years, which is quite far away for a nebula.
NGC 7380 is the star cluster embedded at one side of the nebulosity. It contains mostly OB stars and is very luminous compared to the background nebula.
Sh2-142 is the designation given to the nebula part of this magnificent object and seems to get darker from left to right. The nebula part requires a telescope to be seen. Below the star cluster is the rarest of astronomical rarities, a white reflection nebula. The pearly white colour is due to light in the blue wavelength not being scattered by dust.
|Ced 214 and NGC 7822:|
With shades of dark crimson and angry tones of scarlet, these two large emission nebulae are home to the Cepheus OB4 stellar association.
Ced 214 is a heart shaped nebula with fainter nebulosity extending to the right. The fainter nebulosity is blocked by the cold darkness of dark nebulae.
NGC 7822 is an almost straightened horizontal strip of reddened nebulosity with a star cluster seemingly attached to the right side. The star cluster is NGC 7762 and provides a necessary variety of colours that complement the red colours in this region. Be 59 is a bright blue star cluster between the two nebulae.
Both nebulae are also catalogued as a single Sharpless object, Sh2-171.
|The blazing blue furnaces of the open cluster NGC 7380 sparkle amongst the pink hydrogen gas of emission nebula Sh2-142. Like a pearl in an oyster shell, the uncommon sight of a white reflection nebula can be seen below the star cluster. The dark patches at the left are quite likely to be Bok globules.|
|Image copyright B. Fera|
|Cave Nebula (Sh2-155):|
This intergalactic cave would be impossible to inhabit, the radiation from bright young OB stars would just melt your body!
It consists of hydrogen alpha emission, which means that imaging this with a Ha filter reveals a blanket of surrounding faint nebulosity.
The interior of the cave is represented by blue nebulosity and this is rimmed by bright red emission nebulosity. At the north of the cave is a white cavity like structure that might be a bright rimmed globule.
Near the main structure is a dazzling array of multi coloured yellow and blue stars. There is also the faint blob of a reflection nebula below it and this is known as LBN 524. The LBN stands for 'Lynds Bright Nebula' although the majority of amateur astronomers would dispute the brightness of LBN nebulae. This nebula is also known as vdB155 and widefield images show some Herbig Haro objects nearby.
NGC 7129 is a rich tapestry of blue nebulosity and stars embedded in a dust cloud. It is a crowded jumble of a pillow shaped main cavity structure with a bright arch above the cavity and red and yellow blobs. These blobs are known as Herbig Haro objects.
Herbig Haro objects are created when outflows ejected by protostars collide with the surrounding interstellar medium and the shockwave produces ultraviolet radiation that ionizes the gas. There have been hundreds of this type of object discovered and they were independently discovered by George Herbig and Guillermo Haro in the 1950's.
The left part of the arch has a pinkish ridge along the right side of it. This is excited hydrogen gas and is proof that an extremely high rate of star formation is taking place in this innocuously fluffy cloud. The ultraviolet light from the young stars is beginning to ionize the surrounding gas. In a few thousand years time, the stellar winds will have blown most of the gas away leaving a brilliant sparkling cluster.
|Another one of the few planetary nebulae, NGC 7139 is a magnitude 13 glassy crystalline orb that is red with bright edges. Hydrogen alpha imaging reveals the gas surrounding the central star to be indigo and scarlet.|
|Sh2-129 and vdB140:|
|A C shaped arc of exceedingly faint red nebulosity, Sh2-129 is an 'underground' hit with astroimagers and many like to image it using Ha filters. It is to the right of the much brighter IC 1396 complex. It surrounds a group of stars that give it the ultraviolet radiation required for the ionization of the gas. Near the middle of the arc is a pinkish blob that seems to be attached to the rest of the nebula although it might be either a foreground or background object that shares the same line of sight. Below Sh2-129 is the brilliant glow of a reflection nebula, vdB140.|
This fantastically faint slice of brown dust is dominated by a reflection nebula on one side. The reflection nebula is catalogued as Cederblad 201 and is lit up by a magnitude nine star that had a chance encounter with the dust of a Bok globule called B175. Collectively both objects are known as vdB152.
vdB152 is so faint that it shines at a feeble magnitude 20! Nearby is the almost equally as faint planetary nebula, DeHt 5 and this glows with an ethereal lilac blue glow. The brightest part of this planetary nebula is catalogued as LBN 538.
The Bok globule B175 was discovered a century ago by Dr August Kopff in 1908. August Kopff was the assistant to the well renowned astronomer Max Wolf who discovered some of the nebulae that J.L.E Dreyer added to the Index Catalogue. After the discovery was made, Max Wolf imaged it using photographic plates and detected the reflection part. He dubbed it the Cave Nebula since it was previously unknown as well as the possibility of having the appearance of a cave in his eyes. In this modern age, the nebula catalogued as Sh2-155 is commonly referred to as the Cave Nebula.
In the time since this nebula was discovered, phenomenal technological advances in the fields of optics and electronic detectors have been able to reveal more of the universe. Near Ced 201 is the faint silky strands of an ancient supernova remnant that was discovered very recently in 2001. The supernova remnant is situated below the reflection nebula and between the planetary nebula and a yellow star. This would be impossible to detect through the eyepiece of a telescope, even with astrophotographical means it is almost invisible. Widefield images with exposures taken through a hydrogen alpha filter show two filaments quite clearly that lie at the same distance as vdB152, 1400 light years away. This supernova remnant will collide with the dust cloud in 1000 years time and quite possibly ignite a ferocious bout of star formation.
vdB152 lies in a very interesting area above the galactic plane of the Milky Way.
|Faint and small, this magnitude 13 planetary nebula requires a large aperture telescope to see the two sapphire blue interlapping shells. When observed under dark skies, the nebula is aesthetically pleasing to even the most disenchanted planetary nebula afficianado!|
|NGC 7354 is a brilliant vivid coloured planetary nebula that can only be fully appreciated in large telescopes as it is quite small.|
|A green planetary nebula, IC 1454 consists of a bright inner shell with a faint outer shell that is more apparent in photographs. This magnitude 14 planetary is also known as Abell 81.|
|Image copyright A. Block/August 2008 Workshop Participants/Mount Lemmon SkyCenter/University of Arizona|
|Like a ghost, this nebula is hauntingly mysterious. The tangle of dark nebulae jostle for space with yellowish nebulae, which is a rare colour. The brightest part is the area that contains the embedded star responsible for lighting up the gas and dust and appears as a whitish smudge. Surrounding the nebula are large swathes of dark brown dust that can only be seen in photographs. The nebula is set into a magical field of hundreds of stars, a few bright ones close to the nebula exacerbate the difficulty in seeing it visually. Another more commonly used designation for this nebula is vdB141.|
|NGC 2276 and NGC 2300:|
A curiosity, this pair of galaxies are 100 million light years away and NGC 2276 is known as Arp 25 and NGC 2300 is also Arp 114. The curiosity is due to one being a spiral
Although the deformed appearance of NGC 2276 suggests past interaction with
|Occasionally referred to as the Black Fish, this large dark nebula makes a triangle with Sh2-132 and NGC 7380. It lies near the star, Zeta Cephei as well as the emission nebula, Ced 199. It is visible due to obscuring the Milky Way that surges through Cepheus and rather than being one large obscuring mass, it consists of multiple strands and filaments that vaguely resemble a fish.|
|Gyulbudaghian's Nebula (HH 215):|
This surprisingly delightful nebula that also has an easy to pronounce name is an obscure gem lost in the ocean of the Milky Way.
Like a reflection of Hubble's Variable Nebula in Monoceros, it is a blue fan shaped variable reflection nebula that emanates from the variable protostar, PV Cephei. Since protostars tend to be energetic, a series of knotted jets protrude from the star but they are only visible in photographs. The reflection nebula is situated in front of a cloud of dust, which seems to be prevalent in this area of the sky as there are quite a few other reflection nebulae in Cepheus surrounded by dust.
This nebula was discovered by the Russian astronomer, Armen Gyulbudaghian while he was hunting for Herbig Haro objects at the Byurakan Observatory in 1977.
The 'HH' stands for Herbig Haro and is a compilation of more than 400 Herbig Haro objects that are in the Milky Way. Many of them are extremely tiny and the very few that have been imaged were by professional observatories and the Hubble Space Telescope. A large one that is easy for amateurs to image is the Waterfall Nebula
|Sh2-129 is a brilliant challenge object for experienced observers with large telescopes. The reflection nebula in the lower left corner is vdB140. The dark nebulae at the right are B148-9 and B150 and click the image for a closeup by Giovanni Benintende.|
|Image copyright D. Salman|