ARGOS documentation¶
ARGOS is desktop observing software that turns a smart telescope into a time-series photometry instrument. It records raw FITS with a complete scientific header, solves the field, measures a differential light curve while the sequence runs, and leaves behind a session folder you can reduce independently.
The Seestar S30 Pro is the reference profile; the S30 and S50 profiles remain explicitly unvalidated for precision photometry.
0.4.1 is a field-validation release
It is meant for observers who keep their raw frames and reduce them themselves. There is no weather safety and no restart recovery, so operate the telescope attended — and do not treat the live curve as a publishable measurement. What it does and does not mean is stated in Differential photometry — method and equations.
Start here¶
Twenty minutes indoors: the package, the ASTAP solver and its star database, and the link between them.
One complete session, from the settings you fill in indoors to the folder you hand to Siril at dawn.
What is actually computed — apertures, ensemble zero point, uncertainty budget — with every formula as implemented.
The 65 keywords ARGOS writes, the file naming scheme and the session layout Siril expects.
AUID, check star, ensemble, zero point, green plane, TG — every term this documentation uses, defined once.
Architecture — layer map, threading model, data flow. Seestar protocol — the wire format. API reference — every module, from its docstrings.
What it does¶
The Seestar S30 Pro is a remarkable little telescope for its price, but its native software writes FITS with minimal metadata and offers no scientific workflow beyond “save an image”. ARGOS fills that gap.
An ASCOM Alpaca driver layer reaches the Seestar over Wi-Fi, and the same layer drives the Alpaca simulator — so the whole application is testable without hardware. Jogging falls back to the native JSON-RPC port.
ASTAP recovers a WCS from the green plane, so pixel positions can be matched against Gaia DR3, AAVSO VSX and VSP, SIMBAD and the NASA Exoplanet Archive, and drawn as overlays on the image.
Circular-aperture photometry with a sky annulus, a CCD-equation error budget, an ensemble zero point with robust rejection, and a run-level systematic floor measured from the curve itself.
Per-frame HFD, FWHM, eccentricity, star count and sky level in the FITS headers and in a JSON session record — plus an offline Review workspace to read the night back.
The two-pipeline rule
Display and data are separate pipelines. The raw 16-bit CFA array that comes off the sensor is never modified: it is exactly what gets written to FITS. The screen stretch (linear / log / asinh), the demosaicing (super-pixel / bilinear / raw) and the histogram are all computed from a copy. You can tune the display all night without ever touching the science frame.
Where the boundary is¶
ARGOS measures raw, uncalibrated sub-exposures. That is enough to see that a
variable is varying and that the night is usable — it is not a calibrated
measurement. Darks, flats, registration and final photometry belong downstream,
to Siril and the companion star_var_script, working
on the raw frames ARGOS preserves. The handover is described in Using ARGOS — a complete session,
and the limits in Differential photometry — method and equations.