Ad Astra Observatory

It’s been clear and cold here for the past 3 nights.

I went out two nights ago, and found out that I can see Alpha Columbae down near the horizon. A Col is around Dec -35º. Sure, it would go behind trees a lot, but I’d have a little time to get after it.

M8 is around Dec -25º, so that should pose no problem. I just have to make sure that the scope is situated in the dome to allow viewing down to no less than 15º above the horizon (Dec -47º from here, so call it Dec -32º or so). This actually helps out with observatory design a little, as a requirement of being able to see the horizon means the scope has to stay above the dome wall, but being able to protect the scope a little means a slightly lower pier… Needs to be figured in.

My wife has also suggested that she might take out a couple trees that would otherwise have been blocking my southern sky. Interesting. I’ll see how that figures in, too.

One way or another, between the house (which will block everything up to about 45º elevation in the west) and a very irritating patch of trees in the east (the New Nemesis Palm Tree… grr), I’ll need to model the horizon carefully, to see where the best placement of the observatory will be.

I sketched out what the building must look like if I want to do a lower “warm room” and an upper “scope room”, both with ceilings that are high enough for me to walk around in; I’m sure it comes as no surprise to anyone who’s ever done construction to hear that the two-story solution will result in a building that’s at least 18′ tall. I need to do more drawings.

I got some great news today! Turns out that I have a concrete contractor in the family. He’s offered to help me out with pouring the cement required for the observatory! Awesome! I haven’t really gotten to the part about what the cement will look like; obviously, I need at least a pier. The pier might need a “deadman” at the bottom, especially if it starts getting 10′ or 12′ high to make it into the “upper story”. But I’m not far enough along in design to know whether I want to do a simple deck or some kind of structure, or a foundation… honestly, I think I want to talk with him about the design aspect some, and let him help me figure some of it out. I am grateful to even be considered.

At the moment, I’ve pretty much decided on a dome. And that choice comes down to either a 10′ HomeDome, or a 12.5′ SkyShed POD MAX. The main sticking point right now is whether I buy the dome a la carte, and put a building under it myself, or whether I buy the dome “with walls” and learn to live with whatever compromises that entails regarding getting it just the way I want it. It’s certainly cheaper to build it myself (one assumes that for the approximately $2k – $4k extra that I’m going to be charged for the observatory building by the manufacturer, I could build a pretty extensive shed out of lumber and ply), but it’s more of a turnkey solution to just buy the thing and get running.

My main concern is that both HD10 and MAX have usability problems with the “wall” pieces. The HD10 is very flexible; you buy wall sections 1′ at a time, so you can make the thing any height you want. But essentially, my understanding is that the assumed “dome entry” is to open the dome slit and vault the wall. Also, the 1′ sections look pretty dumb. The MAX goes for more of a “they tried to guess what I’d want” solution, and end up with 6’4″ walls (meaning the scope has to be mounted pretty high up to peer over that, but otherwise nice), but with only a 5’6″ door (sorry, but that’s simply too short. I’m 6’2″, and I banged my head on the observatory door in CA more times than I can count). So either dome is going to need some modification to get the entry and height right, and once I’m going down that road, wouldn’t it be easier to just build the thing myself? I’m torn.

A simple solution might be to have the observatory up on a slightly elevated deck, so that you swing the door open, and there’s a little “trapdoor” in the floor of the observatory at knee level (for instance) that you swing up to reveal 2 or 3 stairs up into the shed. Then you get the shorter door, the benefit of a little more height, and all you have to do is climb a couple stairs. Flop the trapdoor down, and you wouldn’t even know it was there. Might be nice to have a crawlspace under the observatory, for easier access to..? who knows. Anyway, I’m still thinking about it.

If I put up an elevated deck, maybe I could build a foundation instead. I’ve been thinking about building something in brick or stone — makes it feel like I’m doing something permanent.

More drawings.