The roof and the observatory: floor fourteen

Floor 14 is the roof: a lounge with a pool, a viewing deck with three telescopes, and a white dome with a working sky inside it. The sky matches the real one over New York at the time you are standing there.

The deck and the scopes

The lift comes up into a small housing built round the shaft. Its door opens onto timber decking, facing the front of the building. The roof has no ceiling. The sky is the one the street already paints round the building, with a city skyline added round the horizon.

The lounge takes the front of the roof. A stone fire table with a glass guard and flames along it has sofas and deck chairs round it. Planters run along the parapet, which is 3.5 feet high, so you can look over it. String lights hang from posts overhead. A bar stands under a pergola on the east side, with a counter against the parapet and shelves over it.

A pool runs along the west parapet, 30 feet long and about 10 wide, with an infinity edge at the front. You can’t walk in it, and you can’t walk on its loungers either.

The back of the roof is the plant deck, on the grey membrane every flat roof is finished in. Condensers and a vent stack stand behind a fence in the west corner. I fenced them because a condenser fan is not something a guest at the bar should lean on, and I kept them to the back so the lounge faces the view.

The viewing deck is a raised timber deck in the front east corner, 10 feet wide and 18 and a half deep, facing the street, the park and the southern sky. Three telescopes stand along the front parapet, and each opens an eyepiece view when you press E beside it.

Scope	Field of view	When
Tower viewer	9 degrees	Day and night. By day it looks at the park.
Refractor	1.6 degrees	Night
Dobsonian	0.8 degrees	Night

The tower viewer is a coin-op binocular on a pedestal, painted municipal green. The refractor is on a tripod, pointed at the southern sky. The Dobsonian is a big tube in a plywood rocker box. At night you get a round field on the brightest thing up, and left and right move to the next one.

Cloud and rain cap the view. The deck asks the weather for New York, and the eyepiece tells you what it finds: “Raining over New York. Nothing to see tonight.” Snow and fog give the same answer, a storm says the scopes are capped, and heavy cloud says to try again when it clears. A star wheel stands on a post at the back of the deck, and red safety lights sit low at the corners.

The dome and its console

The observatory is a white dome on a dark drum, 20 feet across, west of the lift housing, so the walk from the lift to the lounge goes down its east side. The door faces east onto that walk. Inside, a reflecting telescope stands on a pier that you walk round.

The dome turns. The shutter opens at sunset in New York and shuts at sunrise, and the telescope tilts up through the slit when it is open and parks low when it is shut. A red night light, the one colour that doesn’t spoil your eyes for the sky, and a warm dome lamp come up after dark.

Against the west wall is the control desk. Its left screen shows the moon phase and how much of it is lit, the planets that are up, and either “dome open” or the time the dome opens. A door on the north wall is lettered caelum.network. Press E there and the Caelum site opens in a new tab. Caelum is the observatory project, and this is the room where the building meets it.

Press E at the control desk and the sky console opens. It gives:

• the place, the time, and sunset and sunrise
• the moon’s phase, its percentage lit, whether it is up, and when it rises and sets
• the bright planets above the horizon, with their height and compass direction
• up to ten targets that are up tonight
• the next visible pass of the International Space Station over New York in the next three days
• the night’s meteor shower, if there is one

Pick a target and the dome turns and the telescope swings to its real altitude and azimuth, at 9 degrees a second. Each target links to its page on caelum.network. The panel also shows Caelum’s network status and latest observations when the building is connected to it, and says so when it isn’t.

The panel ends with a warning: positions are worked out here to about a fifth of a degree, and they are not for pointing a real telescope.

Three buttons open larger views:

• Look up. Drag to look around. Scroll or press plus and minus to zoom down to a field of 1 degree. N turns names on and off, K constellation lines, G the city’s glow, V starts the show, and Escape goes back.
• Show. The planetarium show.
• Station view. The ISS cupola over the earth, with the station’s latitude, longitude, height in kilometres and speed, a note on whether it is over the day or night side and in sunlight, and a yellow line showing its next orbit’s ground track.

The show

The planetarium show runs about six minutes. The shutter shuts, the house lights go down, and the dome becomes the sky. The steps are:

1. Tonight’s sky over New York, with the orange haze low down that is the city’s light.
2. An hour every three and a third seconds, so the whole sky turns round Polaris.
3. The Big Dipper and the pointers to Polaris, then Cassiopeia.
4. Orion, with the belt leading down to Sirius.
5. The Summer Triangle of Deneb, Vega and Altair, and Scorpius with red Antares.
6. The planets along the path the sun takes, then a month of the moon in 36 seconds.
7. The city’s lights turned off, so the Milky Way appears.
8. A meteor step, only when a shower is active.
9. A view out past the moon looking down on the solar system, with orbits drawn to scale.
10. The station, about 260 miles up.
11. Back to tonight. The shutter opens again after the show if it is dark outside.

Escape ends the show at any point and brings the lights back up.

Meteors and the weather

The sky follows nine annual showers by the real calendar, from the Quadrantids in early January to the Ursids in late December. The rate each night depends on how high the radiant is, how dark the sky is, and how bright the moon is. A sign on the viewing deck lists the shower, its peak date, the best time to watch and where the radiant is. On a peak night, lawn chairs appear on the deck, reclined toward the radiant. On other nights they are hidden.

Meteors streak across the sky on a shower’s nights, over the roof and in every sky view.

The weather comes from New York’s current conditions, read through the office’s own server and refreshed every ten minutes. It changes the dome, the eyepiece and the street below. The street is the subject of the next post.