Sloan g'r'i' Photometry of the Type Ic-BL SN 2026acxa
ATel #18103; J. Ricra, C. Avalos-Vega, N. Gomez-Pasten, C. Adam, C. Cardenas, J. P. Colque, and E. Unda-Sanzana (Astronomy Center, CITEVA, Universidad de Antofagasta, Chile)
on 13 Oct 2026; 12:53 UT
Credential Certification: Eduardo Unda-Sanzana (eduardo.unda@uantof.cl)
Subjects: Optical, Supernovae
We report optical photometric observations of SN 2026acxa, obtained on 2026 October 01 UT with the 0.6m telescope at Ckoirama Observatory, Universidad de Antofagasta, Chile.
SN 2026acxa (ZTF26abxkuhv) was discovered on 2026 September 25 by the Zwicky Transient Facility (ZTF; TNS Discovery Report No. 324888). The transient is associated with the galaxy ESO 598-017 (z = 0.008089) and was classified as a Type Ic-BL supernova by Balcon (TNS Classification Report No. 24771), Wang et al. (No. 24789), Killestein et al. (No. 24792), and de Wet et al. (No. 24796).
Observations were performed using Sloan g', r', and i' filters, with two 300s exposures obtained in each band. The images were reduced using standard CCD calibration procedures, and instrumental magnitudes were obtained through aperture photometry.
Photometric calibration was performed using standard stars from the Southern Hemisphere u' g' r' i' z' Standard Stars (Smith et al. 2006), specifically the 200000-300000 and SA_140-A fields. Photometric zero points, atmospheric extinction coefficients, and color-dependent transformation terms were determined from the standard-star observations using the photometric transformation equations described in the SDSS photometric calibration documentation.
The resulting photometry, without reddening correction, is summarized below. The reported UT epochs and heliocentric Julian dates correspond to the mean mid-exposure times of the two exposures in each filter.
| DATE-OBS(UT) | HJD | Filter | Exposure (s) | Magnitude | Error |
|---|
| 2026 Oct 01.15505 | 2461314.65834 | r' | 2x300 | 14.830 | 0.009 |
| 2026 Oct 01.16311 | 2461314.66641 | g' | 2x300 | 15.069 | 0.007 |
| 2026 Oct 01.17036 | 2461314.67365 | i' | 2x300 | 14.973 | 0.012 |
The corresponding observed color indices are:
(g'-r') = +0.239
(r'-i') = -0.143
