A Blog by International Students at Leiden University

Sterrewacht Open Sunday – a fun day!



Alright then here is my first blog and it’s about last Sunday – not a good start. Well ideally I should have written this at least 11 days ago so that some of you could have shared my experience but I promise I’ll take care in the future. So, last Sunday was the annual open day at Leiden Observatory (Sterrewacht ) where the telescopes are open to the public for the whole day and for FREE. Since I am a student in the Astronomy department I got an opportunity to show people around the observatory, assist with the telescopes and answer questions from curious Leideners. I must confess that for some of the questions which I didn’t have a clear answer for I would give them a number and say it is within an order of magnitude of the quoted value. I didn’t want to misinform them but didn’t want them to be disappointed at not receiving an answer at all (it always comes in handy if you find yourself in a sticky situation :P).

Although Leiden Observatory dates way back to 1633,  a proper modern establishment was only put in place in 1861 under Friedrick Kaiser. In the 17th and 18th centuries it was housed on the roof of the academy building at Rapenburg. Ours is the oldest university based observatory in the world predating the likes of the Greenwich and Paris observatories.

Image                                                                                            Back in the day

The history of the Sterrewacht is a fantastic read in itself but let me focus on the main attractions here i.e. the telescopes.


(Broadly speaking there are two kinds of telescopes, a refractor where two lenses are used to collect and focus light from a source such as a star to the observer. A reflector does the same job but uses two mirrors instead. Refractors suffer from chromatic aberration which is essentially a rainbow around the object being observed. But these are still usually better than reflectors because some light is always lost in reflection and also the second mirror blocks out some of the light. Also telescopes are characterized by the size of their lens at the front.)

So here’s a quick run of the telescopes open to public:

1) 6 inch Refractor


This is the oldest telescope at the observatory, in fact it is even older than the building itself dating back to 1838. This instrument was used extensively by Kaiser and it is good enough for observing small planets. Since it was daytime we had this pointing to a windmill which happened to be moving.



GenNext Astronomer


Some people found playing with the dome steering quite therapeutic

2) 10 inch Refractor

If I am not wrong then this is the largest refractor in the Netherlands. It was the result of an American-German collaboration back in 1885( when Doc Emmett Brown was rescued by Marty Mcfly). The Americans, Alvin Clark and Sons also made the lenses for the Yerkes Observatory in Wisconsin, which at 40 inch still stands as the world’s largest refractor.


And if you ever visit this and are tired then there is a very special chair to relax your poor muscles. It has been here for decades and Einstein is said to have graced it on several nights so we call it the Einstein chair. Don’t forget to warm it on your next visit!


The Einstein chair

And finally we had a ‘Millionaire’ style Astronomy quiz for kids and rather appropriately the prize was ‘mars’ and ‘milky way’ bars!


There are two other telescopes but these are only open on tour nights and are not used actively. I had great fun showing people around and I promise the next time we have an open event or I am giving a tour I’ll post it here in advance.

Must watch movie # 1

This week’s suggestion is the 1993 thriller ‘The Fugitive’. This is my all time favorite with a gripping story line coupled with James Newton Howard’s musical genius. It almost makes you want to be wrongly accused of killing your wife and run(ride) around the city.

One comment on “Sterrewacht Open Sunday – a fun day!

  1. Sean
    June 30, 2014

    Thank you!

Leave a Reply


This entry was posted on November 6, 2013 by in Authors, Shourya and tagged , , , .

Hit Counter

  • 889,423 total visits!
%d bloggers like this: