DRAFT
2026-03-18 15:43:01
Type: Object/s-Data/Analysis
Bibcode: 2026TNSAN..76....1L
SN 2026fvx: Kinder Follow-up Observations of a Rapidly Brightening Young Type Ia Supernova
Authors: Y.-H. Lee, M.-H. Lee, T.-W. Chen, Y.-C. Pan, H.-Y. Hsiao, A. Dutta, A. Aryan (all NCU), S. Yang (HNAS), C.-Y. Cheng, H.-M. Chang, P.-Y. Wang, S.-Y. Chen, S. Gupta, S. Bhattacharjee, C.-H. Lai, A. Sankar.K, C.-S. Lin, W.-J. Hou, H.-C. Lin, J.-K. Guo (all NCU), D. Xu, Z.-P. Zhu (both NAOC), Z. N. Wang, D. C. Qiang, L. L. Fan (all HNAS), J. H. Gillanders, S. J. Smartt, H. F. Stevance, S. Srivastav (all Oxford), M. Nicholl, M. Fulton, K. W. Smith, C. Angus, A. Aamer (all QUB) and T. Moore (STScI) report:
Source Group: Kinder
Keywords: Supernova
Abstract:
We observed the nearby young Type Ia supernova SN 2026fvx in NGC 4205 (Konno et al., AstroNote 2026-75) with the 40-cm SLT at Lulin Observatory. We measured magnitudes of g = 17.99 ± 0.06, r = 17.97 ± 0.06, i = 18.16 ± 0.06 and z = 18.11 ± 0.10 at +0.58 days after discovery. Compared with the previously reported LAST unfiltered discovery magnitude of 19.64 +/- 0.09, SN 2026fvx was found to be significantly brighter in our follow-up observations, confirming that it is still very young.

We report photometric follow-up observations of SN 2026fvx (Konno et al., AstroNote 2026-75), a nearby young Type Ia supernova in NGC 4205 (17.5 Mpc), obtained with the 40-cm SLT at Lulin Observatory, Taiwan, as part of the Kinder collaboration (Chen et al. 2025, ApJ, 983, 86, doi:10.3847/1538-4357/adb428). We acquired one 300 s exposure in each of the g, r, i and z-bands, with the g-band observation starting at 12:29 UT on 18 March 2026 (MJD 61117.521), approximately 0.58 days after discovery.

We used the Kinder pipeline (Yang et al. 2021, A&A 646, 22) to subtract the images with the SDSS templates and to perform PSF photometry. SN 2026fvx has (AB) magnitudes of g = 17.99 ± 0.06, r = 17.97 ± 0.06, i = 18.16 ± 0.06 and z = 18.11 ± 0.10 at +0.58 days since its discovery. Compared with the previously reported LAST unfiltered discovery magnitude of 19.64 +/- 0.09, SN 2026fvx appears significantly brighter in our follow-up observations, consistent with its being a very young SN and with the LAST report that it was still brightening.

The presented magnitudes are calibrated using the field stars from the SDSS DR18 catalog (Almeida et al. 2023, ApJS, 267, 44). In the direction of the SN, these magnitudes are not corrected for the expected Galactic foreground extinctions of 0.07, 0.05, 0.03 and 0.03 mags (Schlafly & Finkbeiner 2011) for g, r, i, and z bands, respectively. 

Show current TNS values
Catalog Name Reported RA Reported DEC Reported Obj-Type Reported Redshift Host Name Host Redshift Remarks TNS RA TNS DEC TNS Obj-Type TNS Redshift
TNS 2026fvx 12:14:58.133 +63:47:16.41 SN Ia 0.004846 12:14:58.133 +63:47:16.41 SN Ia 0.004846
AstroNote Publication Timestamp Title Authors
2021-92 2021-03-20 17:31:06 Kinder follow-up observations of AT 2021gca (ZTF21aapkbav) T.-W. Chen, S. Yang (Stockholm), Y.-C. Pan, C.-C. Ngeow, H.-Y. Hsiao, C.-S. Lin, W.-J. Hou and J.-K. Guo (IANCU).
2026-75 2026-03-18 12:02:45 AT2026fvx: discovery of a young SN candidate in NGC 4205 (17.5 Mpc) R. Konno, E. A. Zimmerman, E. O. Ofek, A. Horowicz, A. Gal-Yam, S. Ben-Ami, O. Yaron, D. Polishook, A. Blumenzweig, E. Segre, S. Garrappa, A. Krassilchtchikov, M. Engel, Y. M. Shani, P. Rekhi, S. Fainer, S. Spitzer (WIS), P. Chen (Zhejiang University) on behalf of the LAST Collaboration

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