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Markarian's Chain208 viewsDate: 07/03/2011
Telescope: William Optics Zenithstar 110
Mount: EQ6
System: Hutech Focal Reducer 0,85X
Camera: Canon EOS 350Da with LPS clip filter
Exposure: 37X300 sec (3 hours) @ 800asa RAW + darks
Autoguiding: Mitsuboshi Off-Axis Guider with ALccd5 + PHD guiding
Treatment: Deepskystacker and Photoshop
Remarks: first light for the OAG. Great tool. Mar 08, 2011
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Orion Nebula M42237 viewsDate: 30/01/2011
Telescope: William Optics Zenithstar 110
Mount: EQ6
System: Hutech Focal Reducer 0,85X
Camera: Canon EOS 350Da with LPS clip filter
Exposure: 28 min @ 800asa RAW + darks
Autoguiding: Vixen Guidescope with ALccd5 + PHD guiding
Treatment: Deepskystacker and Photoshop
Remarks: bad weather... Feb 05, 2011
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Heart & Soul Nebulae in Cassiopeia239 viewsDate: 17/10/2010
Telescope: Contax Zeiss Sonnar 135mm f:4
Mount: EQ6
System:
Camera: Canon EOS 350Da with Astonomik 13nm h-alpha clip filter
Exposure: 17 X 480 sec @ 1600asa RAW + darks
Autoguiding: Vixen Guidescope with ALccd5 + PHD guiding
Treatment: Deepskystacker and Photoshop
Remarks: First attempt to shoot h-alpha with the modified eos 350da. Needs more exposure...Oct 22, 2010
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Moon and Venus in the West.225 viewsCanon Eos 40d and Sigma 50-150mm at 50mmAug 20, 2010
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 | Backyard Amateur AstronomyWe shall not cease from exploration
And the end of all our exploring
Will be to arrive where we started
And know the place for the first time. . . .
T. S. Eliot
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 | AstrophotographyBetween my 12 and 18 years astronomy was my passion. It was the start of my interest in photography. That's the reason that I became a professional photographer and now a photography dealer.
That why I'm also interested in historical Astrophotography.
After 20 years of occasional observing I took up again my passion.
Necessity creates possibilities: discovering the unexepted possibilities of my equipment is a creative exploration of the mind.
My professional life is very stressing but when looking to the stars the stress disappears. It's a source of energy.
Not the scope is goal but observing as much as possible.
If you should have any comments of questions, don't hesitate to contact me: xavier@debeerst.com.
Xavier Debeerst |
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 | Historical AstrophotographyAstrophotography was one of the first photographic subjects. Photography needed to help astronomers to find answers to some basic questions: is there life on the Moon, how much stars are there and how big is the Universe.
In 2006 I organized a photo exhibition called "Who's afraid of the Dark?" with a lot of unique astrophotos.
In this section you can find a selection of this exhibition. |
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Deep Sky or the photography of the invisible
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Deep Sky or the photography of the invisible
We talk about real astrophotography in photo history when photos are more than just experiements. The start of astrophotography is situated in 1850 (Michael Maunder, the Photohistorian, 09/2005)
Photographers and astronomers of the 19th century were confronted with two restrictions when photographing stars: the low sensitivity of the Daguerreotype and the errors of the telescopes. Since the Earth turns around its axis it's almost as if the stars evolve round an imaginary point (the polar star). Take a look at the nice picture by J.R. Eyerman, 1950. These are 2 problems that modern amateur photographers still have to cope with.
The development of more sensitive emulsions was boosted under the influence of, amongst others, astronomers. The problems concerning the sensitivity of emulsions were solved with the discovery of the wet Collodium and more importantly the improvement of the dry Silver Bromide glass negatives (1874).
In the meantime telescopes and mounts were optimized for astrophotography. All self-respecting observatories installed special telescopes to experiment with the new inventions.
In 1880 the idea was launched to make a photographic star atlas. The Observatoire de Paris took the initiative. The Brothers Henry (Paul, 1818-1905; Prosper, 1848-1903) were important pioneers of this project. In the exhibition you can find an early phto by the Henry Brothers (1886). From a modern point of view this photo isn't that impressive, but in 1886 these photos were very revolutionary. 45 minutes of exposure time was no exception.
The clearest nebulas could now be photographed. It was the Scottish astronomer Isaac Roberts (1829-1904) who was the first to photograph the arms of the Andromeda nebula in 1888. The Andromeda nebula is the closest galaxy to ours.
From that point onwards the discovery of new objects was wide open. Later on it were the American observatories (Lick, Mount wilson and much later Mount Palomar) which took over from European observatories.
The European observatories, which were mostly located near big cities (f.i. Ukkel near Brussels), suffered more from light pollution and became less interesting.
Under impulse of the American photographer Edward Emerson Barnard (1858-1932), who made the first photographic atlas of the galaxy, more and more investments were made in the photography of weaker sky objects. Especially the photos of Mount Wilson were revolutionary. In the exhibition you can see several photos made by the Mount Wilson Observatory.
By 1954 Mount Palomar Observatory made a complete photographical star atlas. This Palomar Sky Survey is still used today.
5 files, last one added on Apr 10, 2006
Album viewed 36 times
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Selonography
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Selenography or the history of the Moon
Stars can only be seen at night.
Photographing astronomical objects is very closely connected with the genesis of photography itself.
In 1838, one year before the announcement of the discovery of photography, by the astronomer - politician Arago before the French parliament, the first picture of the moon was taken by Daguerre. Since the beginning of photography the medium was destined to play an important role in astronomy. Or was it vice versa?
What is the influence of astronomy in the development of photography? Photography was nearly simultaneously discovered by Fox Talbot (1800-1877) in England and Louis Mandé Daguerre in France. Both had relationships in the astronomical scene. Daguerre via Arago and Talbot via Herschel. John Herschel (1792-1871) played an important role in the development of the negative / positive procedure. Hence the hommage of Paul Cava to this important astronomer. Paul Cava is a modern American Photographer who makes photo collages based on historical images. His work can only be viewed on rare occasions in Europe.
Within the Astronomy there were diffirent questions which photography could give a clear answer on: How many stars are there, exact location of the stars, the mutual brightness ratio of the stars, do the Moon and the Sun have an atmosphere.
All over the world, Photographers , opticians and astronomers were trying to answer these questions.
Obviously, the moon was the first object to be photographed. Several moon atlases had already been published before, but there were contradictions between the different publications. Every time there was the problem of the right level of detail. Photography could give a clear answer to this problem.
Whether or not there was life on the moon could also been answered by photography. Even after the first clear photos of the Moon there was still doubt. See "Les terres du ciel", 1884 of Camile Flammarion. Two original Moonphotos (Woodburry types) were published in there. One of those by James Nasmyth was first published in his own book "The Moon considered as a planet". This moonphoto wasn't an original image but a photo of a crater model made out of plaster. For Camille Flammarion it still wasn't clear whether or not there was life on the Moon.
The rare magic image lantern slides of 1870 give a good illustration on the common world view of those days.
It's only because the vulgarisation of the Moon photos in the form of stereo views that the world view would evolve and that it would become clear that the Earth probably was the only inhabited planet. Within the thinking of that time this was an important evolution that was accelerated by astrophotography.
The idea for a detailed photographical map of the Moon was launched in 1887 in Paris. Moritz Loewy (1833-1907) and Pierre-Henri Puiseux (1855-1928) supported by Charles le Morvan (1865-1933) started this ambitious project in 1880. Between 1894 and 1909, about 500 observation nights and over a 1000 takes later the map of the Moon was published in Heliogravure. It took 15 years because only under exceptionally good circumstances ("seeing") the moon could be photographed. The takes were made with the special Coudé refractor of the Obeservatoire de Paris. A refractor with a diameter of 74cm and a focal distance of 15 meters! For this time and age a huge telescope of 6.000 kg.
In the exhibition we have the "Carte Photographique de la Lune" of 1914. This is an addition to the "Atlas Photographique de la Lune" of 1905. The Atlas was completed based upon unpublished images. The photographic Moon atlas of Puiseux, Loewy and le Morvan has become very rare. This is a unique opportunity to view these photographs outside of a museum.
The photographic Moon atlas remained a reference until 1970 when NASA needed a more detailed and more up-to-date Moon atlas to determine possible landing sites for the Apollo flights. Under supervision of the astronomer Kuiper the best moon photos worldwide were assembled. Amongst others, the ones from the Lick observatory were used.
With the uprising of space travel these atlasesl ost their importance. The Moon photos of the different manned and unmanned space flights are used now. See numerous examples in the exhibition.
The apotheosis and the ultimate proof of the absence of life on the Moon was delivered in 1969 with the first man on the Moon. Buzz Aldrin and Neil Armstrong wrote history and provided some icons of Photography. The most well known is probably the portrait of Buzz Aldrin made by Neil Armstrong.
5 files, last one added on Apr 10, 2006
Album viewed 23 times
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| EquipmentEquipment can never be a goal as such but is a priority to use the right equipment for observing and to take photos.
It takes a lot of time and skills to find and match the right tools. In this part of the website you can see the results of this never ending search. |
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| 316 files in 20 albums and 4 categories with 0 comments viewed 23,368 times |
 Random files |
Alcor and Mizar, Ursa Major136 viewsAlcor and Mizar in the constellation of Ursa Major
Date: 11/08/2005
Telescope: Intes M703
System: prime focus
Camera: Canon EOS 300D
Exposure: 10sec @ 3200ASA
Treatment: Photoshop
Remarks:
MIZAR (Zeta Ursae Majoris).
One of the most famed stars of the sky, second magnitude (2.27) Mizar, 78 light years away, is the Zeta star of Ursa Major, the Greater Bear, the second star in from the end of the handle of the Big Dipper, and the Dipper's fourth brightest star.
In large part its fame comes from the coupling of the star with a nearby visual companion, fourth magnitude Alcor, only 12 minutes of arc (a fifth of a degree) to the northeast.
The two, Mizar and Alcor, termed the "horse and rider" by the Arabians, are a good test of minimal vision. The star's Arabic name derives from a word meaning "the groin" of the celestial Bear that plods silently around the north celestial pole (the name mistakenly drawn from Merak, in the Dipper's bowl). However even without Alcor, Mizar takes its place in the celestial hall of fame as the first known "double star," one that consists of a pair of stars that orbit each other. Found to be double in 1650, Mizar is a prime target for someone with a new telescope, as the components are an easy 14 seconds of arc apart (at least 500 astronomical units), the two taking at least 5000 years to make their orbit about each other.
More remarkably, each of these two components is AGAIN double. The brighter of the two contains a very close pair a mere 7 or 8 thousandths of a second of arc apart (an angle made by a penny at a distance of 300 miles) that has an orbital period of 20.5 days; the fainter of them contains a pair with a period of about half a year. Mizar is thus actually a quartet of stars, a double-double. It is moving through space together with its more-distant companion, Alcor. Mizar and Alcor together therefore probably make a quintuple star, Alcor taking at least 750,000 years to make a single round trip around its quadruple companion.
All of the stars are similar, all "main sequence" hydrogen-fusing stars like the Sun, but of white class A (the brighter both A2, the fainter probably both A5 or A7) with temperatures ranging between around 7500 and 9000 degrees Kelvin and luminosities from 10 to 30 times solar. The orbit of the brighter double that makes Mizar has been observed with a sophisticated "interferometer" that makes use of the interfering properties of light. Analysis shows the component stars to have masses 2.5 times that of the Sun; the masses of the fainter pair are estimated at around 1.6 solar. The stars have odd chemical abundances as a result of slow rotation, which allows for quiet atmospheres and chemical separation. The brighter of the pair seen through the telescope is rich in silicon and strontium, whereas the fainter is a "metallic line star" that is deficient in aluminum and calcium but high in silicon and in rare earths like cerium and samarium.
ALCOR (80 Ursae Majoris).
Alcor, forever tied to Mizar, is hardly ever spoken of unless as "Mizar and Alcor," a naked eye double in the tail of Ursa Major that the Arabs referred to as the horse and rider.
The name Alcor, however, was stolen from that for Alioth. Both come from an Arabic word that means the "black horse." The term was distorted in different ways as it was applied to each of the two stars. Oddly, the "rider" of the pair is the one with the name of the "horse," "Mizar" referring not to a horse but to the "groin" of the Great Bear. A great many stars with Bayer Greek letter names have no proper names. Alcor is one of the very few in reverse, a star that has a proper names but no Greek letter name. Instead, it is referred to as 80 Ursae Majoris. In the early 1700s, the English astronomer John Flamsteed organized a new catalogue of stars in which they were ordered from west to east within the constellations, Alcor number 80 in Ursa Major. "Flamsteed numbers" are commonly used when the Greek letter names run out.
Alcor is a fourth magnitude (4.01) white class A (A5) star with a temperature of 8000 Kelvin and a luminosity 12 times that of the Sun. It appears coupled with Mizar, but is it really a physical companion? We are still not sure. Mizar itself is a quadruple star on the "double-double" theme (two double stars in orbit about each other.) Precision parallaxes with the Hipparcos satellite show Mizar to be 78.1 light years away, but Alcor to be 81.1 light years distant.
Mizar and Alcor are part of the Ursa Major cluster, whose core consists of the middle five stars of the Big Dipper. A separation of over three light years, almost the distance between here and Alpha Centauri, would make a gravitational pairing unlikely as the neighboring stars would pull them apart.
The measured errors, however, allow a separation as close as 0.7 light years. The errors in the distances are suspected of being greater than listed, and the analysis of the orbit of Mizar A suggests that Mizar might actually be FARTHER than Alcor! If they are actually at the same distance, their minimum separation is only 0.27 light years, making them close enough so that they could truly orbit, though with a long period of three-quarters of a million years.
For a time Alcor was thought to be double, but it now appears that early astronomers were fooled and that it is really single, rendering Mizar and Alcor together a "quintuple star." While the Mizar stars are slow rotators with peculiar chemical compositions as a result of element separation, Alcor is a rapid spinner (218 kilometers per second, over 100 times solar). As a result, its atmosphere is stirred and its composition normal. It is, however, a slight pulsating variable. The inner five stars of the Big Dipper are all at roughly the same distance and all are normal hydrogen fusing main sequence dwarfs. Alcor's faintness next to the them is a vivid reminder of the role that mass plays in the stars. Alcor's mass is around 1.6 times that of the Sun. Alioth, on the other hand, with twice Alcor's mass, is almost 10 times brighter!
Sourcce: Stars. Written by Jim Kaler
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Perseid: 13/08/2005 00h05 CET45 views
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Double Cluster in Perseus (H & Chi Per) (Intes version)152 viewsDate: 08/09/2006
Lens: Intes M703 + Intes 0.7 Focal Reducer
System: prime focus
Camera: Canon EOS 300D
Exposure: 3 X 180 sec @ 800asa
Autoguiding: Vixen 70S + Atik
Treatment: DslrStar + Registax + Photoshop
Remarks: First attempt with the new combination of the EQ6 and the Intes Mak.
There different problems that need to be solved: finding the right Focal Reducer and of course the main problem remains autoguiding.
The Intes 0,75X Focal Reducer isn't bad. The image circle is large enough for a CCD but to small for a dslr. The result is vignetting. But dramatically, it can be removed with Photoshop. Next step is to test the Celestron 0,64 Focal Reducer. It's also a field flattener. That isn't needed with a Mak. Cas. If that doesn't work the last solution is the AstroPhysics Focal Reducer. The image circle of the AP Focal Reducer is larger than the Intes FR.
The EQ6 hasn't any problems with the Intes and the Vixen. They are sitting very smoothly on the mount. Autoguiding with K3CCD isn't so easy. I still can't manage it completely. For this photo it was ok, but not good enough. I need more usable images at a longer exposure time.
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half moon69 viewsDate: 17/12/2007
Telescope: Zenithstar 110 apo
Mount: Modified EQ6 with Astromeccanica motors and FS2 controler
System: Contax Zeiss Mutar II 2X
Camera: Canon EOS 350D (modified with the Baader filter)
Exposure: 23 photos @ 200asa
Autoguiding:
Treatment: Registax and Photoshop
Remarks:
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