Observatorio " Real de 14 "

[rsbfoto]

Hi,

After 10 weeks building this is my new Observatory

http://rainerehlert.com/ObsReal14/cons/Pano-Obser-07.jpg

and if you want to see the whole construction process look here http://rainerehlert.com/OR14html/

Thanks for looking

[iceman]

Thanks looks fantastic, Rainer. Looks very solid!

Has it had first light?

[h0ughy]

absolutely stunning!! you are indeed lucky and fortunate bloke. It certainly makes use of the area available.

[rsbfoto]

Thanks. Not yet as I am Starting now to install the equipment. 2 Losmandy G11 (not original. modified by me with special worm holders) , 4 tak scopes and a lot of cables ...

As I do not live there permanently I go up there evey 2 weeks, a drive of 420km, it will take some time till I finish.

[rsbfoto]

Thanks, well that is my second one. The room on the left lower side existed alredy when I bought the house so I thought I put on top of it the warm room and on the right side the cold room and so the piers got that huge elevation. Weight of each pier is about 6,000kg. You can see how they were build in the page I set up for the construction process.

[erick]

:scared::scared::scared:

[gmbfilter]

Looks fantastic cant wait to see final pictures
Good Luck

[netwolf]

Looks like a Dream come true Ranier. Congrats.

[spearo]

wow!

[AlexN]

Fantastic set of photos.. And what a lovely finish to the whole observatory...

Looks absolutely stunning! :)

I cant wait to see more pics with all the gear set up :)

Very nice mate!

[rsbfoto]

Hi,

Thank you all for your kind words. Today I am heading 420km North-North West to the Observatory site with the Minivan full of astronomy stuff and a plastic bag with my personal belongings eg. a trouser and a shirt :lol:

Today afternoon I will start laying in the rubber mats in the cold room and then start installing the mounts and telescopes. As we are heading towards Full moon maybe I can focus the Mewlon 250 onto the moon and at least see again the moon :hi:

Hopefully I will be able to post some images with the equipment on top of the piers.

Yesterday the architect did send me some images with the carpenter setting up the furniture and he finished yesterday.

[Ian Robinson]

The building looks like it's concrete , will have a lot of thermal inertia , how much do you think this will effect seeing and imaging from inside the observatory building ?

Will take a long time to equilibrate with the ambient air temp at night I expect so the structure will generate a plume of unsteady turbulent air that you need to view through. Did you take this into account ?


Not on topic : what do you Mexicans make of the american presidential election nonsense that's been going lately ?

[rsbfoto]

Hi Ian,

I appreciate upir concerns bnut the building is not concrete. Is is build with brick which has a completely different mass as concrete.

Here you can see the whole building progress

http://rainerehlert.com/OR14html/

I painted it white in order to have as low as possible heating.

The cold room has 6 ventilation holes in the bottom each 6" diameter and the lower part of the cold room ege. where you can see both piers does not get any Sun in Winter when we have here the best onserving season.

Each pier has a mass of 6,000kg and I guess that is also a good source of lower temperature against the ambient. I have in each pier 2 holes into which I will put a temperature sensor in order to find out how the temperature of the piers evolve with the time.

Yes I did take your concerns into account as there is another astronomer here in Mexico who build his Observatory in a similar way and he has not reported any trouble with the heat generated by his walls and yes he has concrete block walls ando no vents like I did.His Observatory is sitting on top of a water reservoir.

I did take into consideration what you wrote and I said to myself. Better to use in such environment my telescopes as often as I can instead of waiting and having then collecting dust and waiting to go out maybe 2 -3 times a year to a dark site.

I am setting up the equipment and I will see what comes out. As last remedy I can specialize in Moon and Planet imaging which is a lot fo fun too ...

I am working also at the moment to be able to control the observatory remote from where I live.

Anyway I appreciate you having mentioned that posible risk I have and yes as I said I am aware of the possibilities ...

The best telescope one has is the one you use most often.

[rsbfoto]

No Comment.

Honestly :eyepop: I have other problems to think about and they concern the installation of my Astronomy equipment

[Ian Robinson]

If the walls are made of a homogenous material , you need only know the outside and inside temperatures at the surface and the history of the air temperature inside and outside to get a picture of the rate at which the structure will equilibrate. This can all readily be determined marthematically and modelled.

The thermal mass of the walls , suspended floor and massive pedestals will all be significant.

There is a good reason why professional observatories use materials and structures that are of low thermal mass.

The hugely massive piers will heat up slowly in summer and hold most of that heat at night and will radiate and conduct heat to air , .... bad for steady seeing above in the observatory. Gets hot in Mexico I hear , not good. Built now , so maybe you should consider encasing the piers in a low thermal inertia insulating material , this way it wont matter much what the thermal mass of the solid structural piers is, the surface of the insulation will equilibrate quickly and will prevent thermal cycling of the pier and reduce the bouyancy effect that degrades seeing. My reasoning is based on many years as pyromet process engineer and my accumulated experience in thermal engineering.

Thermal properties that might be helpful are :

Bricks have a thermal conductivity k = 0.6-0.7 W/mK
Light concrete = 0.12-0.23 W/mK
aerated concrete = 0.12-0.23 W/mK
Foam glass = 0.04 W/mK
Rock wool = 0.04 W/mK
PVC-foam = 0.035 W/mK
Cavity wall isolation = 0.05 W/mK
cf
Air = 0.023 W/mK

Ideally you structure needs to approach the bulk k value for air to be a good as an observatory , for best possible seeing and imaging.
From Perry's Chem Engr's HB.

The k value will influence how long it takes for the floor and walls to heat up and cool down
The thermal resistance to heat diffusion is R = l/ k , l is the thickness in m.
and U = 1/ (Rso + ∑Rn + Rsi) ,
where Rso is external surface R
Rsi is internal surface R
Rn are other layers' R if different to Rso and Rsi
U is overall thermal conductance from the outside to inside covering all modes of heat transfer.

Qc = U * A * (T outside – T inside) is overall heat absorbed or released.

and the rate of heat transfer can be calculated in 1 dimension using the url here : http://hyperphysics.phy-astr.gsu.edu/Hbase/thermo/heatcond.html

The bouyancy of the warmed air that will flow over the walls is more difficult to calculate , but doable , need to calculate the Prandtl No and the
and the Grashof No to do the Free Convection Calcs. See http://rpaulsingh.com/teaching/LectureHandouts/Convection%20Heat%20Transfer_handou t.pdf.

And the example calcs in http://www.ercoftac.nl/database/test09/test09.html will give the picture of how the bouyancy effect of the warmed air that will effect seeing inside the observatory can be assessed.

Hope that all helped.

[rsbfoto]

Hi Ian,

yes it helped to make me now the most unhappy Observatory owner ...

Tanks a alot

:thumbsup:

[rsbfoto]

Well, looks like that I am not as unhappy as I thought :hi:

Well, I took some days off to install the equipment. Here a few images of how it looks now with some equipment as well as a lot of unsorted stuff everywhere

Entering the cold room (http://rainerehlert.com/ObsReal14/cons/OReal14-01.jpg)

Inside view from warm room to cold room (http://rainerehlert.com/ObsReal14/cons/OReal14-02.jpg)

View of the 2 piers with the G11 mounts and 4 Takahashi telescopes (http://rainerehlert.com/ObsReal14/cons/OReal14-05.jpg)

Mewlon 250 + FS-78 (http://rainerehlert.com/ObsReal14/cons/OReal14-06.jpg)

TOA 130 + Sky 90 (http://rainerehlert.com/ObsReal14/cons/OReal14-07.jpg)

Open Roll Off Roof (http://rainerehlert.com/ObsReal14/cons/OReal14-09.jpg)

Roof half open or half closed :-) (http://rainerehlert.com/ObsReal14/cons/OReal14-10.jpg)

Thanks for looking.

Taking reference to the long posting of Ian in regard to thermal currents I have been doing some temperature measurements at the inside and outside of the walls and it does not look that critical as I read in Ians posting.

Anyhow I am happy now that I can use again my telescopes after nearly 2 years of doing nothing eg. making test from the inside of my appartment in Mexico City.

[Ian Robinson]

:thumbsup:Glad you are happy .

The proof of the pudding will be in how the scopes perform when imaging and doing visual stuff.
And in summer when you are likely to have a larger dally variation in temperature from the coolest part of the night to the hottest part of the day.:D

[rsbfoto]

Hi Ian,

The advantage is that what you call Summer and Autumn here in this part of Mexico we have rain season so it does not matter :thumbsup:. Best time for observing is Winter and Spring.

Thanks

[h0ughy]

oh that is so nice, fantastic result and I love the way you have set things up. :thumbsup:

[Lester]

Fantastic, well done.

Have fun.

[AlexN]

Every back yard astronomers dream come true...

[rsbfoto]

Hi Alex,

Sorry for replying so late. I was busy fiddling out how to remote control my Observatory.

Yes it is nice to have a dry place for the equipment.

[h0ughy]

have a word to Peter ward on this site - he seems to be doing wonders doing just that -remote imaging from his home when he is OS?

[rsbfoto]

Hi Houghy,

Thanks, will do when I have time. The only real problem is at the moment to set up the communication via VNC using DynDNS static IP adress or NO-IP.

NO problem connecting with my PC on the remote location using LogMeIn, but I want to test alternatives