Observatories that I have visited:
Rijeka Observatory, Croatia 2022

Content:

1. The walkway up to Rijeka observatory
2. The panorama terrace and old wooden Newton telescopes
3. The 16" Schmidt Cassegrain telescope
4. The planetarium
5. Old archive photographs

2: The panorama terrace and old wooden Newton telescopes

Our appointment was 2 pm o'clock, we planned to be here earlier to take the outdoors photos before.

Rijeka Observatory:

The stairs climbing are not over yet, but this one isn't many steps. We walk into the building and come to a cafe where we could get something to drink, coffee and juice.

After 15 minutes rest we continue to investigate the observatory. Behind the bar is another staircase that take us up to the panorama terrace.

Our legs tell us that we now have climbed at least thousand of steps.

What a lovely place, an observatory where you can sit at with panorama views with your favorite drink.

This is the view to the Southwest, over the Rijeka harbor. As you see there are parking place up here if you plan to come by car. We saw photos when they have star meetings on the parking place where they have setup their telescopes.

At the end of the terrace is this monocular to get terrestrial views from, or maybe of the night sky too.

The doom to the main telescope.

It has a free 360 degree view. I wish that we had something similar at home in Stockholm.

In the Northern direction it's a mountain, but it's far away and it doesn't block the view.

I'm in pose in front of the dome, happy me !

Gunilla is happy as well to come to this place.

It took us more than three hours to walk to this place but we did almost a one hour stop at the fortress.

At the other end of the terrace is another platform to get views from, Eastern direction.

Elio, our guide:

Now it's time to meet our guide, the staff I was in contact with told that Elio will guide us through the observatory. There are a lot of things here to look at but I said that the telescope is most important and we started with that. Gunilla and I followed him to the control and class room.

Wooden Newton telescopes:

I immediately saw two wonderful Newtonian telescopes. They are so beautiful and I said, wait I must take some photos of them.

They are homebuilt in wood with some plastic and metal parts. This is the eyepiece holder.

This is the smaller of the two telescopes. It has a mirror of 140 mm diameter which was big in the 1970s. The focal length is 1400 mm and with the different eyepieces they used they could get a magnification from 50 to 250 times. The eyepieces must then had focal lengths from 28 mm to 6 mm. It's a f/9.3 opening telescope, called a slow telescope with todays standard.

The mount is built as an Alt-Azimuth mount and this telescope is used for visual observations.

A lid cover the opening to the primary mirror. On a mirror telescope there are demands to adjust the primary mirror, often.

A forum friend to me in Australia have information about this telescope.
Bojan (who lived in Croatia long time ago):
"About that 140 mm Newtonian. I think or guess that it's built with a mirror kit (primary and small rectangular secondary) that was manufactured by "Juraj Vega", optical company from Ljubljana (Slovenia)."

"BTW, my very first telescope was also a 'Vega' (refractor ø45 mm, FL 700 mm). This mirror kit was on sale up to mid 1970s, and I used it to build my second Newtonian, mounted into a frame built using 20 mm extruded aluminum 'L' profile. After the first light, I became aware of the existence of 'pinched optics' (mirror was very thin and had a conical back side)."

Bojan sent me this link about the mirror:

• https://www.astronom.si/ galerija/ index.php? n=6766
(Mirror AT-140)

This is the other Newtonian telescope, it's bigger.

This telescope has a primary mirror with a diameter of 250 mm which was very big at that time. If he grinded the mirror himself he had spent many hours on this telescope. With a focal length of 1500 mm and a primary mirror diameter of 250 mm it gives f/6 opening, a fast telescope. It's suited to observe weak objects like nebulosas.

Even this telescope has an Alt-Azimuth mount. A fine threaded precision screw is used to fine adjust the telescope straight on the object.

The eyepiece holder is of the same construction as on the smaller telescope. It looks to have some fine adjustment of the focus, the black screw behind.

A metal plate with information of the telescope. Made by Prof Dr Ivan Kozulic, 1980. You find more information about this telescope on the last page.

More information about Newton telescope's construction:

• https://en.wikipedia.org/ wiki/ Newtonian telescope
(Newtonian telescope, Wikipedia)