The imaging app
Astrophotography, everywhere.
One app, one workflow, the same experience on every platform. Ara speaks ASCOM Alpaca natively, so it connects straight to your AlpacaBridge device over the network. Set up at the scope, image from whatever machine is in front of you.
- Linux
- macOS
- Windows
- iOS
- Android
Ara is free and open source. Build it from source and it's yours. Ara Pro is the same app as a ready-to-run download, with support, and it keeps the project going.
Connect
Your rig, found automatically.
Launch Ara and it discovers your OpenAstro server over the network. No IP addresses to remember, no cables to your imaging machine.
Pick your rig and go.
Ara lists every OpenAstro server it can see. Tap one and you're in. Hostnames still work for the odd network, and offline mode lets you plan a night without a server in reach.
- Autonetwork discovery
- Offlineplanning mode, no server needed
Setup
Five screens and you're imaging.
The wizard reads your gear straight from AlpacaBridge and connects everything. The only thing it asks is which camera, and only if you have more than one.
Guiding, set up in the same pass.
The wizard connects to OpenAstro Guider, picks the guide camera and mount, fills in sensible defaults, and builds your dark library in the background.
- 1question, and only if you have two cameras
- Darksbuilt on the server, even if you close the app
Equipment, read from the bridge
Camera, mount, filter wheel, focuser, and rotator, confirmed in one step.
Tonight's checklist
Equipment, Smart Focus, polar alignment, and optional calibration frames, in order.
Smart Focus
Nothing to set up. It finds focus for you.
Most autofocus routines want a step size, a step count, and a backlash number before the first run, and a wrong guess gives you a bad curve. Smart Focus measures all of that on your own rig. Connect the focuser, press Run, and it brings the stars to focus.
Finds focus on its own
Start well out of focus. Ara measures stars on binned frames, where even a blurry disc shows up, and walks the focuser toward smaller stars until it passes the sharpest point. Then it sweeps a V-curve around the bottom.
Learns your rig
That first run records how wide your V-curve is and how much backlash your focuser has, and keeps both in your profile. Every move approaches focus from the same side, so backlash never bends the curve.
Refocuses in a few frames
After that, one frame tells Ara how far out of focus you are. It moves straight there and checks, in a handful of frames instead of a full sweep. If something looks off, like too few stars or an 8 °C temperature swing, it runs the full sweep instead.
A V-curve you can read.
Every run shows the measured points, the fitted curve, the star count, and the focused frame, so the result is never a mystery number. A sequence's autofocus leaves the same record, so you can check last night's refocus over breakfast.
- 0focus settings to tune before your first run
- R²fit quality, so you know when to trust it
Your guide scope, in focus too.
Guide scopes and off-axis guiders have hand-turned focusers, so they usually get focused once on a fuzzy star and forgotten. A soft guide star gives the guider less to lock onto, all night.
Ara gives the guide camera its own live focus readout. From the focal length, pixel size, and aperture it works out how small a star your guide optics can show on a typical night, and makes that the target. Turn the focuser, watch the number fall, and Ara calls it in focus when ten frames hold there.
Frames come through the guider, so nothing gets disconnected. With an off-axis guider it waits until the main scope is focused, since the two share focus.
- Targetstar size worked out from your guide optics
- Auto stoponce ten frames hold in focus
- OAGor guide scope, both covered
Manual focuser? Use a Bahtinov mask.
Fit the mask, pick a star, and Ara finds the spikes. A live readout shows how far the centre spike is from focus, in pixels and microns, and calls it the moment you're inside the zone.
- ±26 µmcritical focus zone, computed for your optics
- Livespike offset with a trend over frames
Polar align
Polar aligned, in plain words.
Ara aligns through your guide camera and a plate solver, so there's no polar scope to squint through. One slew measures the mount's axis, then every frame tells you which bolt to turn and which way.
An error you can picture.
Altitude and azimuth each get a plain direction, like Raise or Move east. The quality card says what the error means for your night: how far stars drift in a five-minute exposure, and how it compares with the width of the Moon. Under 2′ the bullseye turns into a fine reticle for the last arcminute.
Once guiding starts, Ara checks again. It reads the alignment that's really left from the guider's own corrections, which catches refraction and flex that a plate solve can't see.
- 1slew to measure the axis, then just turn the bolts
- Moonwidths and star drift, not just arcminutes
- 1 frameto tell you a bolt went the wrong way
A plate solver that uses every core.
Ara ships its own build of the ASTAP command-line solver, changed to spread frame loading, star detection, and the database search across every core of the rig. Same solver, same star databases, just more of the machine working on it. Solves run on the rig, so the laptop or tablet running Ara does none of the work.
No more guessing which star database to download. Setup works out the field of view of your imaging camera and your guide camera, then fetches the smallest database that covers each one. For most refractors that's 109 MB instead of 1.3 GB.
- 3×faster whole-sky solves than stock ASTAP on the same Pi
- ~4 sfor a whole-sky solve, no hint at all
- 0.7 sfor a hinted solve
Measured on a Raspberry Pi CM4 (4 cores) with a 26 MP frame and the D80 star database. Solver time only, compared with the stock ASTAP solver on the same hardware.
Plan
Tonight's Sky picks your targets.
Every object is ranked for your sky, your gear, and your dark window, with the reasoning spelled out. Plan at lunch or days ahead. Ara simulates tonight's sky for your site, and the runs you build are ready to fire when it gets dark.
Frame it on the atlas.
Drag a frame over the target, snap a mosaic grid, and see at a glance whether the object fills your field. Planning works offline, so you can do it anywhere.
- Scoredaltitude, moon, and framing, explained
- Mosaicsdrawn on the atlas, built in a click
Exposure plans, ready-made.
Pick a target and Ara offers exposure plans computed from your optics and sky. Choose one, tweak it if you like, and it becomes a sequence.
- SHOnarrowband
- LRGBbroadband
- Customper filter, everything editable
Sequences
Readable runs that roll with the sky.
Every run is a list of visible instructions: cool the camera, unpark, slew, autofocus, guide, image through each filter. Rearrange, validate, save. No hidden state.
Build it by dragging.
Frame a grid on the atlas and Ara expands it into one sequence per panel, each centred, rotated, and imaged through your filters. Coming from N.I.N.A.? Import the runs you've already built.
- Mosaicsexpand into per-panel sequences
- N.I.N.A.JSON imports, 3.2 and later
Stay in control while it runs.
Watch each step tick off with a live progress bar and time remaining. Clouds during OIII? Jump ahead without abandoning the rest of the night. When you resume, Ara plate solves to confirm you're still on target.
- Pauseand pick up where you left off
- Skipan instruction when clouds roll in
- Triggersrefocus on HFR rise, dither on a schedule
Run complete
A tally of every frame by filter, one tap from the library.
Review every frame
Linear or stretched, rate it, tag it, and see the capture metadata at a glance.
Live
The whole night, on one screen.
Live shows the last frame, camera and cooling controls, frame statistics, and the guiding graph together. Nothing to switch between at 2 a.m.
Image and guide, side by side.
Take a single frame or loop live. The guiding panel plots RA and Dec corrections with every dither marked, and diagnostics and faults surface right beside the camera controls.
- RA + DecRMS, peaks, and dither markers
- Solveany frame for its sky coordinates
Guide settings measured, not guessed.
Ara reads the guide camera's pixel size straight from your Alpaca server, and with an off-axis guider it takes the focal length from your main scope. Tap a star and watch OpenAstro Guider calibrate. Ara judges the result and tells you why, so a bad calibration never hides.
Then run PHD2's Guiding Assistant right from Ara, on whatever device you're holding. It measures your mount's drift, your seeing, and Dec backlash, then suggests the guide exposure, minimum move, and backlash compensation to use. Tick the ones you want and they're saved to the guider.
- GoodCheck, or Redo, with the reason
- 2 minGuiding Assistant run is plenty
- Acceptthe suggestions you want, written to the guider
Guiding that recovers on its own.
When a cloud takes the guide star, Ara pauses the run and picks it up again as soon as the guider locks back on.
A long cloud is harder. The mount drifts while nothing is guiding it, and when the sky clears the star is no longer where the guider is looking. So after a few minutes Ara starts checking the guide frames. Once stars are back, it re-centers your target by plate solve, restarts guiding, resumes the run, and leaves you a note saying so. If that doesn't work, the run stays paused and Ara tries again a few minutes later.
Dithers recover the same way. A brief star loss is waited out, guiding that has stopped is restarted (after a long gap Ara re-centers first), and the next frame never starts until the star has settled.
- Pausewhen the guide star is lost, resume when it’s back
- Re-centerby plate solve after a long cloud, then guide again
- Settledafter every dither, before the next frame starts
Devices
Every device, first-class.
Mount, camera, focuser, filter wheel, rotator, flat panel, dome, weather, safety monitor, switches. Each gets a full settings page with live status, manual controls, and auto-connect on boot.
Multiple switches, at the same time.
Most imaging apps let you control one switch device. Ara connects to all of them. Run your power box and dew-heater controller side by side.
- 2+switch devices connected at once
- Eachwith its own ports and toggles
Weather that can call the night.
Live conditions from your station, with safety limits that pause a run before the sky turns on you. With the OpenAstro SQM WeeWX plugin, sky darkness in mag/arcsec² sits right beside temperature and wind.
- SQMsky quality from your WeeWX station
- Thresholdsfor cloud, wind, humidity, and dew point
Mount
Live RA/Dec, park and home, and a slew pad with speed presets.
Camera
Cooling, gain and offset defaults, and binning.
Filter wheel
Name every slot once and Ara uses it everywhere.
And more
The details that add up.
Your imaging life, in numbers.
Nightly streaks, total integration, and per-session analytics like focus against temperature, guiding RMS trends, frame quality, and a calendar heatmap.
- Streaksand achievement badges
- CSVexport of everything, any time
Find anything, instantly
Hit ⌘K on macOS or Ctrl+K on Linux and Windows, type "dither", "park", or "go to run", and jump straight there. No digging through menus with a red headlamp on.
Your frames, your disk
Save to any drive, pick FITS with RICE compression, get warned before space runs low, and keep backup snapshots.
Free to build. Pro to run.
Ara is in active development and step-by-step guides are being written. Sign up on the Ara Pro page and we'll send one email when it launches.