Embark on Celestial Adventures: Unveiling the Marvels of the Night Sky with the iAstroGraph App, Your Smartphone's Ultimate Astrophotography Companion

Abstract

Smartphone-based astrophotography is increasingly recognised as an accessible platform for astronomical observation and data acquisition. However, variability in imaging parameters such as exposure time, lens aperture, ambient light intensity, and optical alignment can significantly influence the reproducibility and analytical reliability of captured sky images. Preliminary colour-standardisation experiments demonstrated that brightness correction using a standardised parameter substantially reduces pixel variability in astrophotographic imaging. Experimental evaluation using the iAstroGraph system analysed a subset of 100 imaging samples randomly selected from a dataset containing 16 colour standards spanning the Red–Violet spectrum. For the single Red-Violet standard, the standardised dataset exhibited a standard deviation of 3.87, compared with 28.54 in the non-standardised dataset, demonstrating a significant improvement in imaging reproducibility. Across all 16 colour standards, the mean standard deviation decreased from 34.28 to 4.92, while the mean error percentage declined from 63.71% to 46.12%, confirming the stabilising effect of the colour-brightness correction algorithm. Statistical analysis was conducted using Microsoft Excel (Microsoft Corporation, Redmond, WA, USA) to compute mean RGB values, standard deviations, error percentages, and post-hoc statistical power estimation (power ≈ 97%, α = 0.05, β ≈ 0.03). The iAstroGraph smartphone application (Version 1.0) integrates brightness correction, photon number percentage estimation, stellar colour classification, and sky-background analysis to support enhanced interpretation of smartphone-captured astronomical images. The system enables practical applications including deep-sky imaging, variable star monitoring, meteor observation, aurora photography, comet tracking, planetary imaging, and constellation analysis using smartphone-telescope assemblies. This paper presents the operational framework, analytical workflow, and performance characteristics of the iAstroGraph system as a multifunctional smartphone-based astrophotography analysis platform.