Stars of the Night
Sidera Noctis was built to serve as a practical resource for observational astronomy enthusiasts, students, and citizen scientists. The site provides tools that support the full workflow of an observing session — from weather assessment and target selection to field data collection and sky quality research — and educational content on topics like light pollution that affect the quality of the night sky.
All astronomical calculations are performed entirely in the browser using algorithms from Jean Meeus, Astronomical Algorithms, 2nd edition (Willmann-Bell, 1998), with no external computation services required. Weather and forecast data are drawn from public sources including the NOAA/NWS Weather API, Open-Meteo, and NOAA GOES-19 satellite imagery. The site uses no third-party analytics, collects no personal data beyond what users voluntarily submit through the field data tools, and serves no advertisements.
Sidera Noctis is developed and maintained by Wes, a professor of physics, astronomy, chemistry, and mathematics at a regional institution of higher education.
His teaching and research interests center on observational astronomy, sky quality measurement, and light pollution — with a particular focus on developing accessible tools and field methods that students and amateur astronomers can use to contribute meaningful data.
The tools on this site implement well-established algorithms from the astronomical literature. Solar, lunar, and planetary positions are computed from the truncated VSOP87 theory (Bretagnon & Francou 1988) and the Meeus Ch. 47 lunar series (23-term longitude, 14-term latitude). Rise, transit, and set times use the sidereal hour-angle method (Meeus Ch. 15). Magnetic declination is derived from IGRF-14 coefficients (IAGA, epoch 2025.0). Sky surface brightness modeling follows the calibration of Duriscoe, Luginbuhl & Moore (2007, PASP 119, 192).
Transparency estimates use a 0–8 scale adapted from observational field survey methodology (Gokhale 2019). Seeing estimates are derived from dew-point spread, relative humidity, and wind speed as boundary-layer turbulence proxies. These atmospheric estimates are indicative — direct instrument measurements are always authoritative.
Sidera Noctis is an actively maintained project. If you find a bug, have a suggestion for improvement, or notice a calculation that seems incorrect, your feedback is welcome. Please use the site feedback form to report issues or suggest features.