Deep in rural Thailand, far from European light pollution, a remotely operated observatory is taking shape — dedicated to the observation of dynamic events in our Solar System. While Europe sleeps, RTNPY gazes into the clear tropical sky. And you? You sit comfortably at home with a cup of coffee, watching the data come in.
- Time offset of +5/+6 hours: Astronomical events that occur in European daylight take place at convenient observing hours over Nong Pok Yai.
- Geographic complementarity: Occultation paths that miss Europe frequently sweep across Southeast Asia.
- Climate: The dry season from November through February offers a surprising number of clear nights with calm seeing.
- Low geographic latitude: Objects of the southern celestial hemisphere and the ecliptic rise much higher above the horizon than they ever do from Central Europe.
The observatory is designed for time-critical, high-precision photometry:
- Stellar occultations by minor planets (asteroids): Millisecond-accurate light curve measurements to determine size, shape and possible companions.
- Mutual events of the Galilean moons: Eclipses and occultations among Io, Europa, Ganymede and Callisto.
- Lunar occultations of stars: Especially grazing occultations and occultations of bright stars.
- Exoplanet transits as well as variable and eclipsing binary stars.
- Comets and Near-Earth Objects (NEOs): Astrometry and photometry.
The following list outlines a setup that meets the scientific objectives while satisfying the demands of a fully remote-controlled robotic observatory.
| Component | Recommendation | Rationale |
|---|---|---|
| Main telescope | Ritchey-Chrétien 14" (356 mm), f/8 | Large aperture, flat field, coma- and chromatic-aberration-free imaging for photometry |
| Guide scope / finder | APO refractor 80/480 mm | Alternative to off-axis guiding; wide-field search and astrometry |
| Reducer/flattener | 0.67× reducer (f/5.4) | Wider field of view and shorter exposures for occultation work |
- Direct-drive mount (e.g. ASA DDM85, 10Micron GM2000 HPS or Planewave L-500): absolute encoders, no periodic error, payload capacity ≥ 50 kg, pointing model suitable for unattended operation.
- Massive pier thermally decoupled from the building floor.
| Purpose | Camera |
|---|---|
| Science camera (photometry/astrometry) | Cooled CMOS, e.g. ZWO ASI6200MM Pro or QHY600M (full frame, 16 bit, low read noise) |
| High-speed occultation camera | QHY174M-GPS or ASI174MM with GPS module for absolute time stamps below 1 ms |
| Autoguider | ZWO ASI220MM Mini or equivalent |
| All-sky camera | ZWO ASI224MC + fisheye lens for cloud monitoring |
- Filter wheel with 7 positions, motorized.
- Photometric filters: Johnson-Cousins B, V, R, I and Sloan g', r', i'.
- Narrowband filters Hα, OIII, SII for supplementary imaging sessions.
- Luminance / IR-cut filter for occultation observing with maximum SNR.
- GPS-disciplined time server (e.g. Meinberg LANTIME) with PPS output.
- Camera with hardware GPS trigger — mandatory for asteroidal stellar occultations.
- NTP synchronization of all control computers against the local GPS server.
Rather than a conventional roll-off roof, RTNPY will be housed under a classical observatory dome — exactly as depicted in the rendering above. The dome offers superior protection against tropical wind, driving monsoon rain and the intense daytime sun, while a narrow shutter slit shields the optics from local stray light and dewfall.
A particular strength of this project: the dome will be designed and built by local Thai craftsmen. Thailand has a long tradition of skilled metalwork, fiberglass fabrication and precision carpentry. Building on site means:
- Lower cost than shipping a commercial dome halfway around the world.
- Local know-how for ongoing maintenance and repairs.
- Community involvement — the observatory becomes a local landmark, not a foreign installation.
- Custom adaptation to the climate, the pier geometry and the specific telescope.
The dome will feature a motorized rotation drive, motorized shutter, safety limit switches and full ASCOM/Alpaca integration for remote control.
- Weather station: cloud sensor (Boltwood Cloud Sensor III), rain sensor, anemometer, hygrometer, temperature, sky brightness (SQM).
- UPS providing at least 30 minutes of backup — graceful shutdown on power loss.
- Climate-controlled electronics room separated from the optics (tropical climate!).
- Redundant internet connection: fiber as primary, 4G/5G as backup.
- Remote-controlled power distribution (PDU) — every component individually switchable.
- Surveillance cameras with infrared illumination for visual checks from afar.
- Acquisition / control: N.I.N.A., Voyager or ACP Expert
- Plate solving: ASTAP or PlateSolve2
- Photometry / analysis: Tangra (occultations), AstroImageJ (transits), Muniwin
- Weather / safety logic: custom automation with hard-abort on clouds or rain
- Remote access: VPN plus remote desktop, redundantly secured
Picture this: It is 7 p.m. in Central Europe. In Thailand, it is one in the morning. The sky stands clear and steady at the zenith. A 14-inch mirror gathers the light of a 12th-magnitude star — and in exactly 47 seconds, an 80-kilometer asteroid beyond Mars will extinguish its light for 4.2 seconds. You watch the star on your screen. The GPS-clocked camera counts the frames. And your measurement helps give shape, for the very first time, to a rock drifting through the outer Solar System.
That is RTNPY.
Location: Nong Pok Yai, Thailand · Operated remotely from Europe