Universiteit Leiden

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Open Dag

Open Day Old Observatory

Sunday 27 October 2019
Oude Sterrewacht
Sterrenwachtlaan 11
2311 GW Leiden

Practical Information

Free entrance. A small fee is charged for a limited number of activities.

We strongly recommend travelling to the Old Observatory by public transport. 

There are some parking spaces on the Sterrenwachtlaan, but these are reserved for residents of the street. These cannot be used by visitors of the Old Observatory. There are a number of parking lots available in Leiden. For their locations, you can look at the website of the Leiden municipality.

On Sunday 27 October, the annual open day of the Old Observatory will take place. During this day everyone can visit the Old Observatory for free and enjoy activities in the historic building.

The doors open at 12:00 and close again at 17:00. Visitors can participate in various activities from children's workshops and planetarium shows to lectures and quizzes; for young and old there is something fun to do.

Below you find the full programme for the Open Day.

The activities

SpaceEU ‘Step into Space’ - Exhibition

Room: B005 & B006, times: continuous, tickets: none

Step into Space is an exciting new touring exhibition developed by Ars Electronica, which brings together space sciences and art to inspire youths and their families.

Thousands of discoveries have been made in space that we now use in our everyday lives. Space exploration allowed us to innovate in health care, energy and the environment, everyday technology, and many other areas. It assists us in thinking about how to collaborate to protect our planet, and it continues to inspire us to think outside the box. The achievements of space science have shown us that we can make the impossible possible. Curiosity and exploration are vital to the human spirit and so we invite you to join us on a journey of discovery through this exhibition. We want to share the story of space and your part in it.

Exhibition Artists: Sarah Petkus (US), We Colonised the Moon (DE/ UK), Nuotama Bodomo (GHA/ US), Eva Rust (CH)

Exhibition Partners: Sentinel-hub EO-BrowserESA AppsNEUROTH



City tour ‘wandelen tussen de sterren’ - Jos van den Broek (NL)

Times: 13:30, 15:30, duration: 1 hour and 30 minutes, tickets: €4 (regular), €2 (student), gratis (<18 years), available at info point near the main entrance, maximum number of visitors: 15

In many places in Leiden you can see that man has always been fascinated by celestial phenomena: from ancient Egyptians in the museum of antiquities and Balinese and Aztecs in the museum of ethnology to Gerrit Dou's astrologer in De Lakenhal. More recently Einstein and De Sitter discussed the stars and Oort, Van de Hulst and Mayo Greenberg made important discoveries. Leiden research in physics and astronomy is also world-class now, with scientists such as Ewine van Dishoeck, Jan Zaanen, Carlo Beenakker, Xander Tielens and Marijn Franx. A scientific walk along physics and astronomy can therefore rightly be called 'walking between the stars'.


Guided Tours (Building and historic telescopes)

Room: Visitor centre, times: every 30 minutes, starting 12:30, duration: 30 minutes, tickets: €4 (regular), €2 (student), free(<18 years), available at info point near the main entrance, maximum number of visitors: 15

Are you curious what secrets and anecdotes are floating around in the hidden of the Old Observatory? Then let yourself be guided by an astronomy student! Each tour includes a visit to one telescope, plus some other spaces in the observatory building.


Above and Beyond - Exhibition

Room: visitor center, times: continuous, tickets: none

In the Observatory’s basement you can visit the temporary exhibition ‘Above and Beyond: Making Sense of the Universe for 100 Years’, which was designed in honour of the 100th anniversary of the International Astronomical Union. It showcases some of the most significant and surprising astronomical breakthroughs that have shaped science, technology and culture over the last century. The exhibition has an interdisciplinary and international scope, outlining that scientific discovery is not a one-off endeavour but a continuous process that takes decades to fully grasp and comprehend. It is underpinned by three core questions that are just as penetrating today as they were a century ago: What is the size and structure of the Universe? Is there life beyond the Earth? What powers the stars, how do they begin to shine and what happens when they die?


Planetarium shows

Room: C-hall, times: every 30 minutes, starting 12:30, duration: 30 minutes, tickets: €4 (regular), €2 (student), free(<18 years), available at info point near the main entrance, maximum number of visitors: 20

Due to the amount of light pollution in the Netherlands, it is very difficult to see many objects in the sky at night. But not during the Open Day! Take a journey in our planetarium through time and space to distant planets, nebulae and maybe even black holes!


Zunderman & Fotograaf telescopes

Room: towers outside, times: continuous, tickets: none

Two of our historic telescopes are placed in separate towers, outside the building; the ‘Fotograaf’, our biggest refracting telescope, that was used to take photos of astronomical objects, and the Zunderman telescope, a Reflecting telescope with a special history. 

These two towers can be visited freely during the open day! Specialists who can tell you everything there is to know about the telescopes will be present in the domes.


Light Lab (WLS)

Room: Kaiser room, times: continuous, tickets: none

Looking at stars involves more than just pointing a telescope. Light has all kinds of interesting and sometimes crazy properties that we have to take into account. Visit the Light Lab to see what kind of effects light can cause.


Children's activities

Room: Meridian Lounge, times: continuous, tickets: none

What would aliens look like? How do you build a good satellite? These kinds of questions keep the smartest astronomers busy every day. But that doesn't mean you can't think along! In the children's corner, you can try to come up with a solution for these problems yourself.


Space Lounge

Room: C003, times: continuous, tickets: none

Take some time to relax in the ‘Space Lounge’ and talk with your friends, family or Leiden astronomers about some topics that occupy astronomers as well as non-scientists.

Every once in a while there will be short lectures or quizzes to give you some food for thought. Enjoy the following activities:

  • Astronomy on Tap (EN) - quizzes
  • Book presentation ‘De Zaak Zonnestelsel’ - Simon Portegies Zwart
  • Lecture by SRON-scientist - Jochen Landgraf (EN/NL)

(More details will be added)

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