Star-field sources

This noncommercial demonstration renders catalogue objects for the forecast pointing. It is not a live camera image or a calibrated 300-second telescope exposure. Bright stellar cores and halos use an illustrative profile; no DSS2 image or derived texture is used. Galaxies and nebulae have schematic catalogue shapes, not photographic textures; clusters and dark nebulae have catalogue outlines. Objects with known magnitudes fainter than 14 are omitted from the deep-sky layer; entries with unknown magnitudes retain catalogue markers.

Star names and constellation abbreviations are cross-matched to HIP identifiers from the IAU WGSN catalogue snapshot of 4 April 2022 (411 HIP matches), used with attribution to the International Astronomical Union. Unnamed stars keep their catalogue identifier.

Deep-sky data: OpenNGC v20260501 by Mattia Verga, under CC BY-SA 4.0. Our adapted JSON catalogue keeps positions, dimensions, position angles, V/B magnitudes, common names, and Messier/PGC cross-identifiers, and excludes duplicate, stellar and nonexistent entries. The adapted catalogue is shared under the same licence at /catalog/openngc.json. We acknowledge OpenNGC's sources: NASA/IPAC NED, HyperLEDA, SIMBAD at CDS Strasbourg, HEASARC, and Harold Corwin's NGC/IC data.

Solar System positions and magnitudes: Astronomy Engine by Don Cross (MIT). Topocentric J2000 coordinates use the observatory latitude, longitude and elevation at scenario time, including light-time and aberration corrections. Live positions update once per scenario second. Exposure comparisons use the same midpoint position on both sides; they do not integrate planetary or lunar movement during the exposure. Discs and colors are illustrative; illuminated fraction is listed in the object card.

This work has made use of data from the European Space Agency (ESA) mission Gaia, processed by the Gaia Data Processing and Analysis Consortium (DPAC). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement.

Gaia DR3 positions, proper motions, G magnitudes and BP−RP colors are obtained through CDS VizieR I/355. Available sampled XP mean spectra for G < 12 are obtained through Gaia@AIP, under CC BY-NC 3.0 IGO. Spectra are integrated over 360–830 nm to CIE XYZ and converted to D65 linear sRGB. Invalid spectra retain approximate catalogue colors. G/V brightness proxies do not reconcile those passbands.

Bright sources missing a nearby Gaia counterpart are supplemented from Hipparcos I/239. Hipparcos B−V and Gaia BP−RP colors are approximate display colors where usable spectra are absent.

CIE 1931 2-degree color-matching functions: CIE 2019, DOI 10.25039/CIE.DS.xvudnb9b, CC BY-SA 4.0. Interpolation weights and the resulting spectral color conversions are derived from this table and shared under the same licence.