architecture of observatories - help needed

4696 views
7 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    December, 2009
architecture of observatories - help needed
Posted by tarikBA on Tuesday, December 08, 2009 1:03 PM

I'm an architecture student and for my degree thesis i have to design small professional astronomy center. It has to include small planetarium, one bigger dome with telescope, and any other required additional spaces. I would be greatly thankfull if someone could tell me what other spaces are required (other than control room), and what should I include. Also, I have never been at any observatory, and currently I don't have a chance to visit one (I've been to planetarium once) :( Basicly, any kind of help is appriciated since I'm unable to find any literature on this subject.

Moderator
  • Member since
    July, 2002
  • From: Texas
Posted by chipdatajeffB on Tuesday, December 08, 2009 4:20 PM

If this is for a thesis project, then you should take the time to visit a real observatory. That would give you the best insight into the problems to solve.

Here is a short list:

  1. Type of observatory/size of instrument(s): is this for a giant telescope doing research, or something like an outdoor education center? If the former, then the design challenges will be more technical. If it's for the latter, then appearance and utilitarianism will be more important. Most such educational centers equipped with planetarium are designed as multi-use facilities, to allow generation of income to support the science activities.
  2. What sort of planetarium will it be and how many people will it seat? Will it be central to the operation, with small telescopes wheeled out for public observing nights, or will the observatory be the main operation with the planetarium used for cloudy nights (as a Plan B)?
  3. Any public building in the USA which hopes to raise funds as part of its operation needs to be ADA-compatible, with wheelchair ramps, doorways wide enough for access, etc.
  4. If the observatory has a telescope larger than just a few inches, it will need a concrete plinth set deeply into the group. This often requires several tons of concrete. The larger the scope, the large the plinth needs to be. The size of telescope dictates the size of the dome. The size of the dome dictates the strength needed in the ring wall that supports the dome. The type of telescope dictates how high it will be mounted (the base of the mount for a large refractor needs to be higher, to allow the scope to rise above the lower lip of the dome shutter for observing targets at low altitudes, for example, but a Schmidt Cassegrain can be mounted much lower (or the dome can be on shorter walls) because the optical tube is no more than half the length of a refractor of the same focal length.
  5. If the observatory is going to be in the mountains or other locations where snow can be a problem, then roof pitch needs to be steeper.
  6. Classrooms or media rooms may be needed for an educational center, but are less likely to be included in a research observatory setting.
  7. If the observatory is primarily for research, then it may be sited near a mountaintop with a visitor's center and control room at a lower elevation (for more comfortable use).

This list could get quite long. The important thing is to surf around for "observatory" and look at some of the buildings you see to determine how you want to design this. Many professional observatories have nearby learning centers or Visitors' Centers for public outreach. The McDonald Observatory, in Texas, has several large observatories, several smaller ones (including two dedicated to the Visitors' Center), plus a Visitors' Center / Learning Center / Gift Shop ... but no planetarium. The Griffith Planetarium (California) is planetarium first, observatory second, but accommodates both purposes. Many smaller college observatories are multi-use facilities incorporating a planetarium as about half the building, a large dining room, smaller meeting rooms, and small observatories (often separate buildings).

If you can't visit an observatory, at least search the Web for them. Then decide on the purpose of the facility prior to determining how much to build, and what it will house.

The universe is not only stranger than we imagine, it's stranger than we CAN imagine. --- JBS Haldane

Come visit me at Comanche Springs Astronomy Campus (we're on Google Maps) in Texas.

www.3rf.org

  • Member since
    December, 2009
Posted by tarikBA on Tuesday, December 08, 2009 9:37 PM

First of all, I would like to thank you for your effort - this is indeed valuable help for me.

 I'll try to reply point by point. I have a lot of questions, but I'm sure that I still won't ask everything i wanted :)

1. I have done a lot of web resarch on observatories, but most of available data is concerned with amateur observatories. I'm from Bosnia, and my project is supposed to be located here. Astronomy is not widely spread science here - in fact I managed to find only one professional astronomer here (although there are meny amateur astronomers), and couple of people from university that were involved in astronomy. He provided me with some basic info about astronomy and observatories. With his help I made some analysis about ideal location for new observatory, but soon I realised that I was heading in wrong direction. All my potential locations were suitable for, let's say, resarch used observatories - they were on higher altitudes with clear horizonts, but were far from cities so nobody but astronomers would ever come to visit it. Since there is only limited number of potential professional astronomers, I rejected that idea and turned to designing an observatory dedicated to popularisation of science. Something like that "multi-use facility" you mentioned - to satisfy both scientific and educational needs, but also to be able to make some income.

My questions would be - how big should the telescope be?

What are the size ranges of amateur and professional telescopes? (OK, I know that 3m telescope is not amateur :) ).

What are the benefits of bigger telescope? (e.g. Do you see further or clearer than with a smaller one?)?

 How big should the dome be? Can the dome floor be on the same level as other rooms (e.g. control room, maybe classroom, laboratory, office... etc.). I'm asking this because I've read that observatory walls should have low thermal mass which creates some issues about integrating it with other parts of the building.

2. Regarding the planetarium, I think that it should have around 35 seats - the size of  average school class. It should encourage all schools to send kids here to gain some knowledge about astronomy. Pretty straightforward idea as you can see. So, planetarium will mainly be used by public, but it could also serve for other purposes.

3. I'm aware of this, and I have acquired general EU regulations for people with disabilities. I'll aim to satisfy all of the requirements, and I've actually found manufacturer that provides instrument that allows handicapped access to the eyepiece for most telescopes.

4. I've managed to find several good sources about telescopes and domes. Construction itself is not my main concern at moment - I can get informations about domes and particular telescopes, and then solve construction problems together with my professor (provided i use prefabricated dome). I'm aware of the fact that telescope pier should be orientated true north-south (or celestial north), and that it should be made of concrete.

5-7. These are helpfull informations and I'll have them in my mind.

I've already surfed a lot, but as I've already mentioned, I'm unfortunatelly not in position to visit any observatory at this moment. There is a lot material on the web, but mostly about amateur observatories. I can't find any floorplans of bigger observatories which is still my main problem. I've found floor layout of Griffith observatory planetarium, and that was huuuuuge help and solved many of my questions regarding planetariums.

For the end, the most stupid question of all :) What do the astronomers do during the day in observatory, or when they can't observe the sky due to bad weather?

 Thanks again for everything, and I'm sorry for my ultra-newbie questions :)

Moderator
  • Member since
    July, 2002
  • From: Texas
Posted by chipdatajeffB on Wednesday, December 09, 2009 12:58 AM

tarikBA

1. ... All my potential locations were suitable for, let's say, resarch used observatories - they were on higher altitudes with clear horizonts, but were far from cities so nobody but astronomers would ever come to visit it. ...

My questions would be - how big should the telescope be?

My suggestion would be about a half meter ... Something like an RCOS or PlaneWave 24-inch scope is large enough to provide a Wow factor at the eyepiece yet still fit in a 20-foot diameter dome. Both are readily available commercially. The price tag for this combination will be in the $250,000 (USD) range, including quality construction. On the other hand, a 16-inch Schmidt Cassegrain from Meade, or a 14-inch Cassegrain from Celestron, including a smaller dome and quality construction, would be well under $100,000 if that's a more suitable budget.

What are the size ranges of amateur and professional telescopes? (OK, I know that 3m telescope is not amateur :) ).

The 200mm SCT is the most popular size of commercially available scope for amateurs. But that size is not large enough to give much of an impression when observing something like galaxies and nebulae. Your starting point should be about twice that. For typical public outreach programs in the US, many clubs have public viewing nights in public parks. Their members bring their telescopes and share with the public. It's pretty common to find at least one or two 300mm scopes at such events, and it is becoming more common to see something like a 400mm dobsonian scope there.

Typical dobsonian scopes are not well-suited to observatory placement. They're made for easy assembly/disassembly and are quite portable even in sizes up to 400mm to 500mm. In sizes above about 300mm, the average person needs a stepladder to reach the eyepiece ... hence these are not the best design for access by a broad range of people.

An SCT has its eyepiece on the bottom end, so it can be made accessible to those who must remain seated for observing. The periscope-like device that is used for accessibility by wheelchair-bound people works quite well with this design.

What are the benefits of bigger telescope? (e.g. Do you see further or clearer than with a smaller one?)?

A telescope gets it[is to gather light. The larger its aperture (diameter), the more light it gathers. The more light it gathers, the better it sees dimmer objects. Most galaxies and nebulae are too dim to see well in small scopes. The brighter planets (and the Moon, of course) do better with more magnification. Therefore, the SCT design (which packs a lot of focal length and aperture into a physically small package) is quite popular.


 How big should the dome be?

For public access, as large as possible. Ash Dome models are available up to about 28 feet in diameter ... almost 10 meters. Such a dome can accommodate about 25 to 30 people around a large amateur-class SCT on its pier without overcrowding. At Comanche Springs Astronomy Campus, where I work, we have such a dome, equipped with a 15-inch (~400mm) refractor. This is not the best choice for a public facility, but it was available to us at a good price. Such a telescope is quite impressive to look AT (if not as impressive as a larget SCT to look THROUGH), and the public really enjoys it. You can see it and the observatory at our Web site: www dot 3RF dot org), or click here.

I would suggest a minimum of 12 feet diameter for a dome for public use. You can shuttle people into the dome in groups of about a half dozen pretty readily.

Can the dome floor be on the same level as other rooms (e.g. control room, maybe classroom, laboratory, office... etc.). I'm asking this because I've read that observatory walls should have low thermal mass which creates some issues about integrating it with other parts of the building.

For public use, yes. This is why the Griffith facility has domes at the ends of the building. Low thermal mass is more important for research purposes. Public observatories often include air conditioning and heating, set appropriately for the season for observing rather than for comfort: enough hit in the wintertime to offset frost, for example. But for best observing, you want the inside air to be at the same temperature as the outside air. There is an effect called "dome seeing" (air turbulence induced by body heat and building heat) you want to avoid. The easiest way to do this is to minimize the number of people in the observatory (under the telescope) at one time, and to use a large dome shutter opening (to release heat to the atmosphere more readily). Most observatories I've seen use exhaust fans or very large doors at the four compass points, to move air through the dome more effectively. Generally, the idea is to keep the telescope objective or mirror (which can have very large thermal mass) as near as possible to ambient outside temperature, and to prevent rapid and large swings in temperature.

3. I'm aware of this, and I have acquired general EU regulations for people with disabilities. I'll aim to satisfy all of the requirements, and I've actually found manufacturer that provides instrument that allows handicapped access to the eyepiece for most telescopes.

I've seen the "inverted periscope" designs, which work best with SCT type scopes. To make large telescopes wheelchair-accessible, some facilities use ramps or lifts. It will be important to use an angled-fork mount to allow the eyepiece to be offset as far as possible from the pier ... for wheelchair accessibility.

For the end, the most stupid question of all :) What do the astronomers do during the day in observatory, or when they can't observe the sky due to bad weather?

Most observatories have a good library(!). For daytime use, consider a solar telescope. These work best when the observatory itself is closed to the outside air. In one popular design, a mirror called a heliostat outdoors reflects an image of the sun through a glass port or a tunnel into a darkened room, through a proper solar observing filter (these are either a white-light filter or an etalon or other hydrogen-alpha filter) indoors for observing. For a white-light telescope, the image can be projected onto a wall or a tabletop for direct viewing. The Mount Wilson and Kitt Peak public solar observatories use this method. But h-alpha filters are quite dark and generally you view the image from a digital camera, on a computer monitor.

The h-alpha design is more difficult to build as an indoor/outdoor setup, so most of these that I have seen are set up totally outdoors, with a portable shade used to minimize intrusion of stray light.

And, of course, the planetarium shows are your biggest draw for cloudy days/nights, or during the daytime.

The universe is not only stranger than we imagine, it's stranger than we CAN imagine. --- JBS Haldane

Come visit me at Comanche Springs Astronomy Campus (we're on Google Maps) in Texas.

www.3rf.org

  • Member since
    December, 2009
Posted by schizlee on Thursday, December 10, 2009 12:13 AM
“If you can't visit an observatory, at least search the Web for them. Then decide on the purpose of the facility prior to determining how much to build, and what it will house”.    

In order to have a good observatory has two parts what can seen and who get to see it. I say let the telescope size dictate planetarium size. The largest telescope in the USA only a small hand full get to see it. P.B.S  TV.  Both a telescope and a Planetarium must be electronicly linked together otherwise only telescope operators see all. We only see what they publish.  Telescope operators (they get very testy then it comes to their eye in sky or their bread & butter) they don’t want John Q Public around.

Tags: Missed used
  • Member since
    November, 2013
Posted by shona on Thursday, November 14, 2013 11:14 AM
hey..even i m doing my thesis on a astronomy center...i m getting problems in my thesis report, please can you help me..
  • Member since
    August, 2004
Posted by stars4life on Tuesday, December 10, 2013 7:13 PM

I don't know if this will help... or just make matters more confusing... Either way... enjoy!

http://www.hohmanntransfer.com/top/obs.htm#obsam

Moderator
  • Member since
    July, 2002
  • From: Texas
Posted by chipdatajeffB on Tuesday, December 10, 2013 9:55 PM

If you have specific questions not covered above, I might be able to help ...

The universe is not only stranger than we imagine, it's stranger than we CAN imagine. --- JBS Haldane

Come visit me at Comanche Springs Astronomy Campus (we're on Google Maps) in Texas.

www.3rf.org

Join our Community!

Our community is FREE to join. To participate you must either login or register for an account.

ADVERTISEMENT

FREE EMAIL NEWSLETTER

Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter.

ADVERTISEMENT
ADVERTISEMENT
Find us on Facebook

Loading...