gajdusek-kozelsky (15)

The Heliostat by Frantisec Kozelsky

The archive of the Zdanice is about 90 large cardboard boxes full of documents.
When I filled the boxes at the observatory I didn’t have the time to select or to look at the documents.  My time was so limited that I only could empty the cabinets ad fill the boxes
Now I have some more time and I discover box by box.  Not all the documents are interesting.  I don’t throw away any document.  I try to find some order and logic.
I don’t speak, write or read Czech.  I recognize some words. 
First I have to scan the documents with OCR soft and then I use Google Translate.  This is enough to get an idea what the document is about.
If it is interesting I rewrite the text. 

I think it will take a couple of years before the complete archive will be inventoried. 

Some documents are very relevant such as a letter by Frantisec Kozelsky about the motorization of the heliostat. 
The letter dates from 1998.  The observatory opened in 1963 and closed in 2002.  So it’s at the end of the observatory.
The project was to use the heliostat to project the solar disc on the roof of the planetarium.
The planetarium was never finished because of financial troubles.  Only the dome existed.  The Zeiss instrument was never installed.

I didn’t find the heliostat.  Only the unfinished optical system to enter the sunlight in the planetarium.

The letter and the plans illustrate very well the way Kozelsky prepared his projects.

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25 years anniversary of the Zdanicy Observatory

In 1991 the Public Observatory of Ždánice exited 25 years.  At this occasion an article was written in the Czech astronomy magazine Říšehvězd (Empire of stars).  The article briefly outlines the history of the observatory.

The construction of the hotel isn't mentioned in the article. 

The plans for the observatory were made by Ing. Marie Kotíková and Rudolf Pavlik.
Since July 1958 a workers brigade prepared the construction of the building by gathering the building material.  The pupils of the  Ždánice school cleaned  more than 60 000 used bricks.

The construction started on 11 October 1958. In 1964 the constructor OSP Hodonin head-quartered in Kyjov, was added to the workers brigade which finished the construction of the observatory in 1965.

On 28 November 1965 the Public Observatory in Ždánice was inaugurated with a regional astronomical workshops.

The names of the people who have most contributed to the construction of the observatory should be honoured. First of all the contractor of the observatory and its long time manager ing. Oldrich Kotik.  Furthermore, members of the astronomical club, of which the best volunteers were involved for more than 100  hours: Miroslav Kincl, Ing. Marie Kotíková, Oldrich Polacek, Francis Hegr, Antonin Balat, Jan Fiala, Oldrich Marta, Jaroslav Leskovská, Anthony Black, Stephen Skokan, Ladislav Stepanek and Ladislav Stork. They did an excellent job.

The creators of astronomical instruments are Ing. William Gajdušek from Ostrava, who was responsible for the optics and Frantisek Kozelský of Stará Bělá at Ostrava who made the telescope mounts.
Both made the following instruments: two refractors with a diameter of 155 mm and 200 mm on equatorial mounts installed in the domes of the observatory, a Schmidt camera, coelostat, two Cassegrain reflectors with a diameter of 250 mm, a refracting telescope with a diameter of 156 mm on portable azimuth mount.
The 10cm coronagraph was  made by JUDr. Karl-Hermann OTAVSKÉ from Černošice, (Prague) with optics made by Vilem Gajdušek.

At its opening the cost of the observatory was 813 thousand. CSK.  The trade unions paid 75% of the cost of the building. The cost for the telescopes and the interior design was 287 thousand. CSK. When the observatory was finished in 1965 the total cost of the observatory was 1.1 million CSK (€40.700)

The Public Observatory of Ždánice was during the first 25 years of it existence very popular with youngsters.  Since 1978 every year there was a summer school “observing variable stars”. This summer schools were not only popular in Czechoslovakia but also abroad.  
In total 26 astronomy youth camps were organized in Ždánice.

The local astronomy club let by Petr Kucera organizes public lectures and every week there was a public observation night.

In the first 25 years of its existence about 250.000 people visited the observatory.

 On the occasion of this jubilee organized by the Public Observatory of  ŽDÁNICE and in collaboration with the Observatory and Planetarium Nicolaus Copernicus from Brno on 1 and 2 December 1990 an astronomical seminar was organized.

For those interested in the observatory can contact Peter Kucera.

At this occasion RNDr. Vladimir Kotik's wrote a booklet "25 years of the People's Observatory in ŽDÁNICE 1965-1990."
It has 92 pages, 52 figures and costs 15 CSK. It describes the  history of the construction and operation of the observatory and in the end also a brief history of the state-owned enterprise Šroubárna Narex Ždánice.

Vladimir Kotik

Říšehvězd, June 1991

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Other telescopes by František Kozelský

In my research for more background information about the Gajdusek-Kozelsky telescopes from the Zdanice Observatory I found an article in the Slovak astronomy magazine about a similar 20cm refractor build by Kozelsky.

After more than two years of hard work, the famous telescope builder František Kozelský from Old Běleja (Ostrava) build a refractor for observatories in his workshop.  The telescope will be installed in the observatoriy of Kysucké Nové Mesto.

It is the largest device of this type made by  František Kozelský and one of the  largest refractors in the Slovak Republic, dedicated to  amateur astronomy. We asked  the telescope designer a more detailed description of the new apparatus. He is willing and show the huge telescope. The telescope was completely setup in the hall of his house.  It’s the only place where he can mount the telescope.
In the next editions of our magazine we will report on the further installation of the telescope in the observatory

The device is built on a strong conical steel frame which ensures the stability of the telescope. The lens is from Zeiss Jena (type AS, 200 mm, f = 3000 mm). Equatorial mounting is driven by a synchronous electric motor (10 W, 3000 rpm] via a gear box with a planetary gear, which allows using the second electric motor, A hand box allows guiding in the right accession.  The drive is mounted in such a way that there is no vibration. The gearbox is permanently filled with oil. The telescope is equipped with hour circles for fine adjustments . On the setting circles eyepieces are installed for a detailed read out.

The focuser is designed for rapid exchange of eyepieces and other auxiliary equipment. On the telescope tube a Schmidt Camera is mounted with a mirror diameter of 200 mm f: 2.44.  The camera has a field of view of 7 degrees. The diameter of the film cartridge is 58 mm. The Schmidt camera was made by Ing. Wilhelm Gajdušek.

The telescope is equipped with a viewfinder with a diameter of 80 mm ff = 450 mm], which magnifies 16x. the viewfinder includes eyepieces for 75, 110, 150, 200, 313 and 600x.

Other accessories are: a zenith prism, also a Herschel wedge for direct observation of the Sun with polarizing filters and various other filters, a 3 eyepiece revolver for quick exchange of eyepieces and a solar projection screen 35 x 35 cm.

František Kozelský spend 2.5 years building this telescope

Kozmos, March 1980

The 20cm telescope described in this article is still in use in the Hlovohek Observatory.

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Spring in November.  That's the actual weather in Belgium. 
Very strange weather.  Mosquitoes in November...

Result of this warm weather is a lot of dew and fogging.  Not the best observation conditions.
A good dew controller is needed.


The 160mm f:15 Gajdusek-Kozelsky refractor is installed in the observatory on the Fullerscopes MK IV equatorial mount.  Tracking and GOTO is now possible.  The Fullerscopes MK IV is a classic heavy duty mount retrofitted with stepper motors and an FS2 controller.

The Gajdusek-Kozelsky refractor is originally mounted on the original altaz mount.  

It's only a 16cm refractor but it's an impressive heavy telescope.Steel tube with balance weights inside the tube.

With a length of 240cm and a weight of +/-30kg it's the limit for the MK IV.  But the system works very smooth.

The focuser is a nice oversized 2" rack and pinion.  Very smooth.  Perfect for fine focusing at high magnifications.

The zenith prisms are an original 30mm made by Kozelsky and a 2" made by Zeiss.

Observation report

First views were very disappointing.  Blown up stars and a very bad star test. Almost impossible to focus the image.  Compared the images with the views from the 10cm Polarex.  Pinpoint stars and almost textbook star test.

After 45 minutes the Gajdusek-Kozelsky was cooled down and ready for the real work. Pinpoint stars!
First object: Aldebaran.  Red giant.  Perfect colour and deep black background.  Started with a 50mm 2" Rini eyepiece.  Pushed the image to 400x with an Abbe Zeiss 6mm ortho eyepiece.  Dimmer view but almost no colour aberration.  A little green border.  Up to 300X no trace of false colour.  Remarkable result.
Enough technique.  Time to enjoy deepsky objects.

The pier of the Fullerscopes is made for the 30cm Cassegrain and not for a long tube refractor.  Not the most comfortable observing position.  So limited to lower situated objects. The pier should at least be 75cm higher. 

First deep sky object were the Pleiades, open cluster in Taurus.  Pin point stars.  The field of view is to small to observe the complete cluster.  Bud large enough to see the three triangles.

Of course the Orion Nebula.  Low at the horizon just above the houses.  Nice fit in the 31mm Nagler.  Compared to the 4" Polarex much more detail.
A long tube refractor is excellent for faint stars.  Challenge to observe the E-star (mag 10.3) in the Trapezium cluster inside the Orion Nebula.  Could easily see the E-star.  Not possible with the Polarex.

The three open clusters in Auriga were the next objects.  Already higher in the sky.  Not so easy to observe.  Seated on the ground of the observatory.  Beautifll.

The back to Orion for double star hunting. Beta Orionis or Rigel was an impressive split.  Already visible with the 31mm Nagler but best with a Circle T 12.5mm Ortho

The Quadruple of Sigma Orionis was very interesting.  The seeing wasn't longer good.  Could only see the C-star with averted view.  Same with the C-star of Struve 761.

Last object was the open cluster M35 in Gimini.  I always compare M35 with an open hand full of shiny diamonds.   The companion cluster NGC2158 was visible, faint, only with averted vision.

Ended the observation session at 4am...

It was a great night.  Enjoyed a lot the 160mm Gajdusek-Kozelsky refractor.  Would it be with the 20cm (8") refractor?

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The 16cm f:15 Gajdusek Kozelsky refractor is installed on the Fullerscopes MK IV mount.  This heavy duty mount from the 1950's carries the refractor very well.

Now it will be possible to observe more objects because the Fullerscopes has the GOTO function.

The equatorial mount will make it possible to use higher enlargements.  It will also be possible to use the refractor for astrophotography

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The Zdanice Observatory in the press

First newspaper article about the building of the observatory in 1960

News paper articles from the Zdanice Observatory archive. Starting in 1960 until 1989.
It must have been a famous observatory at that time.

Artist impression of the observatory

The observatory was build by the local community

The finished observatory without the hotel.

About 15.000 people a year spend the night in the hotel. A special rail road was build to Zdanice. The observatory was famous for the research of variable and double stars. A lot of visitors came from the USSR.

1986 Observatory and hotel

The 3 domes of the two refractors and the later added planetarium

The domes of the 20cm refractor and the planetarium

The 20cm f:15 Gajdusek-Kozelsky refractor? Now in our warehouse.

1961 the process of the building of the observatory

The 16cm Gajdusek-Kozelsky refractor

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Star Diagonal Prisms for the Gajdusek-Kozelsky refractors

Handmade Star Diagonal Prism for the 16cm refractors.
The eyepiece size is 30mm and not the contemporary 31,5mm.
Works very well with Leitz microscope eyepieces.

Large 2inch star diagonal prism for the 16cm refractor.
Heavy piece bud fits perfect the refractor.

There is no indication of a brand on this piece.

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First light of the 16cm f:15 Gajdusek - Kozelsky refractor

7 June 2015

Last first light for the Gajdsuek_Koselsky 16cm refractor on the Alt Azimuth mount.
I don't know when it was the last time scope saw star light?

Two photos of how I found the scope laying in one of the domes.

The other photo is the scope standing in the garden ready for observation.

Refractorphil and his son joined for the first light.

It was a little puzzling to find the right pieces to fit the eyepieces. When you use an Altaz mount it's difficult to use high power eyepieces. Between 60x and 150x were ideal.

First object was Venus. Clean view with no secondary colors. Second object was Jupiter. Splendid view. Lot's of details in the clouds and a beautiful shadow transition. Details of the poles. Crispy.

Startest: textbook. What I hoped.
Double-Double in Lyra: clear split at 100x.
M13: Beauty
M57: lot of details.

Conclusion: The scopes is great. Easy to use. The focuser is a joy. Simple mount.

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A family shot of the different focuser of the scopes.

On the left the Cassegrain Focuser, middle the 16cm refractor focuser and right the 20 cm focuser.

The eyepiece attachment system is very similar to the Zeiss system.
This are the 3 different eyepiece dovetails from the different focuser's. It are Zeiss style dovetails. Or are it original Zeiss dovetails?
More and more I find indications that Kozelsky knew very well the Zeiss Jena material.
The large Zeiss Jena scopes were "common" in Eastern Europe.

The sizes are:
The smallest from the Cassegrain: focuser side: 63.5mm, eyepiece side 54,7mm
Medium size from the 16cm refractor: focuser side 71,6mm, eyepiece side 71,2mm
Large size from the 20cm refractor: focuser side 94,5mm, eyepiece side 88mm

All the focuser and draw tubes have different sizes.

For the people who love stories.  Found all the adapters in a cooking pot in one of the hotel chambers ;-)

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Vilém Gajdušek and František Kozelský

Vilém Gajdušek (1895–1977) was Czech optician and prominent telescope designer. Asteroid 3603 Gajdušek is named for him.

Asteroid 8229 is named in honor of František Kozelský (1913–2003 ), a Czech telescope maker well-known for his work in collaboration with V. Gajdušek. Kozelský. Kozelský made several 60cm Cassegrains and a series of 20cm refractors for observatories in Czech Republic, Slovakia and the rest of former Eastern Europe.

Hvězdárna Ždánice (1963) was the first big project by Gajdušek and Kozelský.  The Public Observatory had two domes with a 20cm and 16cm equatorial mounted refractors, two 25 cm Classical Cassegrain and a set of smaller optical instruments.  With it annual 15 000 visitors it was one of the most succesfull observatories of Eastern Europe in the 1960’s and 1970’s.
Now the observatory is closed.

155mm f = 2 400 mm achromatic refractor made by Vilém Gajdušek, optics and František Kozelský, telescopes and mount.
The refractor is mounted on a 250kg equatorial mount  The optics were made in 1958 and the telescope in 1962

200mm f = 2 870 mm achromatic refractor made by Vilém Gajdušek, optics and František Kozelský, telescopes and mount.
The refractor is mounted on a 250kg equatorial mount  The optics and the telescope were made in 1969

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Tale of an abandoned Czech Public Observatory

About a month ago a received an offer for buying the abandoned Public Observatory of Zdanice in the Czech Republic.
The observatory was build in the 1960’s, the communist era of Czechoslovakia.  It was abandoned after the revolution when the subventions dried up and the founder died.
The Observatory consists of two parts: the original Observatory and a later added hotel.
The hotel is in very bad condition.  Very expensive to restore and no added value to the observatory.  The observatory is worth restoring.
My initial idea was to keep the observatory and to take down the hotel.  Impossible to get a permit.
The only option was to buy only the inventory of the observatory.  
After we closed the deal I got the message that I only got one week to remove the inventory.  Panic but ok.  Found a team of six people and a transporter.
It’s a ones in a lifetime opportunity.  So adrenaline is very helpful ;-)
In the inventory are included a 20cm f:15 and 16cm f:15 equatorial mounted refractors in 4.5meter domes.  Another 16cm refractor and two 25cm Classical Cassegrains on altaz mounts.
A 20cm Schmidt camera and 10cm Coronagraph who were mounted on the  scopes.
Fantastic instruments build by Prof. Ing. Vilém GAJDUŠEK (optics) and Frantisek Kozelsky (mounts and hardware).
The scopes are very professionally made.
The mounts weight about 250kg.
Beside the optical instruments there was a library, movie theatre and a planetarium.  Unfortunately the planetarium projector was already moved to the Brno observatory.
It was a huge library of about 15.000 books in Czech, Russian, German and some in English.  
Only a small part was astronomy related.  The library also served the local community.
In the movie theatre I found about 60 astronomical films.
The observatory was very successful and was one of the largest public observatories in Eastern Europe.
The future of the building is very uncertain.  There are several claims on the ground and building.  

I found the observatory as a time capsule.  Very weird.
It was like they closed the doors fifteen years ago and we opened it again for the first time.  
All the rooms and offices were intact. 

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