AstroNote 2026-105

We report detailed multi-band photometric monitoring of SN 2026dix, followed intensively through the BHTOMnetwork from pre-maximum through well into the declining phase. MASTER discovered SN 2026dix on February 16, 2026 (followed up). It was then followed-up by ZTF, GOTO, LAST, ATLAS, and WFST as well. It was classified as a Type IIb SNe with a redshift of 0.003185, and the spectrum also showed H and HeI absorption lines at about 20000km/s supporting the classification (Pursiainen et al. 2026).

Photometric follow-up by the BHTOM.space network commenced on February 18, 2026, just two days after initial discovery, and is still ongoing. Photometric follow-up has been carried out by the 0.68-m Horten telescope Horten Videregaende Skole (Norway), 25-cm Adonis Observatory Telescope (Belgium), 41-cm School Astronomical Observatory Bolecina (Poland), 50-mm Seestar-S50, 0.6-m Cassegrain Zeiss telescope Mt. Suhora Observatory (Poland), 50-cm Corrected Dall-Kirkham telescope of the Astronomical Observatory of the Jagiellonian University (Kraków, Poland), 60-cm UwB Astronomical Observatory Telescope (Poland), 35-cm Maksutov telescope Moletai Observatory (Lithuania) and 70-cm Planetarium Slaskie Telescope (Krakow, Poland). Photometric observations were taken in g, r, i, z, u, B, V, U & R filters and subsequently transformed into Gaia Synthetic Photometry (GaiaSP) for consistency.

Notably, a subset of photometric data points was acquired with the ZWO Seestar S50, a compact, consumer-grade smart telescope operating in the G and R equivalent bands, demonstrating the accessibility of this bright, nearby event to small-aperture and citizen-science class instrumentation.

The transient appears to peak around March 10–14, 2026, at ~15–14.7 mag in the redder bands, with an estimated rise time of ~24 days. However, the absence of host-subtracted photometry and the diversity of follow-up instruments introduce scatter that limits precise interpretation. Nevertheless, the dataset enables a qualitative morphological study of the light curve evolution. With dedicated analysis and careful curation of the photometric data—particularly homogenization across instruments and improved background subtraction—further physical interpretation may become possible.

Detailed light curves and associated statistics are presented on the webpage: https://bhtom.space/public/targets/SN 2026dix. Further details and the full photometric dataset are available for download by registered users of the BHTOM.space platform.

Acknowledgements: BHTOM.space is based on the open-source TOM Toolkit by LCO and has been supported by the European Union's research and innovation programmes under grant agreements No 101004719 (OPTICON-RadioNet Pilot, ORP) and 101131928 (ACME).