_version_ 1866909998889566208
author Wang, J.
Xie, W. J.
Cangemi, F.
Coleiro, A.
Li, H. L.
Xu, Y.
Han, X. H.
Yang, H.
Xin, L. P.
Mao, X.
Zheng, J.
Jin, J. J.
Li, G. W.
Rodriguez, J.
Tao, L.
Cordier, B.
Wei, J. Y.
Bacon, P.
Bellemont, N.
Bouchet, L.
Cai, H. B.
Cavet, C.
Dai, Z. G.
Godet, O.
Goldwurm, A.
Guillot, S.
Huang, L.
Huang, M. H.
Jiang, N.
Liang, E. W.
Lu, X. M.
Schanne, S.
Stum, S. Le
Qiu, Y. L.
Wang, X. G.
Wang, X. Y.
Wu, C.
Zhang, L.
Zhang, S. N.
author_facet Wang, J.
Xie, W. J.
Cangemi, F.
Coleiro, A.
Li, H. L.
Xu, Y.
Han, X. H.
Yang, H.
Xin, L. P.
Mao, X.
Zheng, J.
Jin, J. J.
Li, G. W.
Rodriguez, J.
Tao, L.
Cordier, B.
Wei, J. Y.
Bacon, P.
Bellemont, N.
Bouchet, L.
Cai, H. B.
Cavet, C.
Dai, Z. G.
Godet, O.
Goldwurm, A.
Guillot, S.
Huang, L.
Huang, M. H.
Jiang, N.
Liang, E. W.
Lu, X. M.
Schanne, S.
Stum, S. Le
Qiu, Y. L.
Wang, X. G.
Wang, X. Y.
Wu, C.
Zhang, L.
Zhang, S. N.
contents Detection of stellar flares at hard X-ray is still rare at the current stage. A transient was recently detected by the hard X-ray camera, ECLAIRs onboard the SVOM mission at 11:39:01.2UT on 2025, January 09. Simultaneous monitor in the optical band on the ground by SVOM/GWAC and follow-up spectroscopy enable us to confirm that the transient is caused by a superflare on HD~22468, a RS CVn-type star. The bolometric energy released in the flare is estimated to be $\sim7.2\times10^{37}-1.7\times10^{38}\ \mathrm{erg}$. The hard X-ray spectra of the event at the peak can be reproduced by the ``apec'' model of a hot plasma with a temperature of $106^{+27}_{-22}$~MK. In the optical range, the H$α$ emission-line profile obtained at $\sim1.7$ hrs after the trigger shows a bulk blueshift of $-96\pm20\ \mathrm{km\ s^{-1}}$, which can be explained by either a chromospheric evaporation or a prominence eruption. The ejected mass is estimated to be $3.9\times10^{20}$ g for the evaporating plasma, and to be $3.2\times10^{21}\ \mathrm{g}<M_{\mathrm{p}}<8.8\times10^{21}\ \mathrm{g}$ for the erupted prominence.
format Preprint
id arxiv_https___arxiv_org_abs_2601_16558
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Multi-wavelength Study of A Superflare on RS CVn-type Star HD22468 Triggered at Hard X-ray by SVOM
Wang, J.
Xie, W. J.
Cangemi, F.
Coleiro, A.
Li, H. L.
Xu, Y.
Han, X. H.
Yang, H.
Xin, L. P.
Mao, X.
Zheng, J.
Jin, J. J.
Li, G. W.
Rodriguez, J.
Tao, L.
Cordier, B.
Wei, J. Y.
Bacon, P.
Bellemont, N.
Bouchet, L.
Cai, H. B.
Cavet, C.
Dai, Z. G.
Godet, O.
Goldwurm, A.
Guillot, S.
Huang, L.
Huang, M. H.
Jiang, N.
Liang, E. W.
Lu, X. M.
Schanne, S.
Stum, S. Le
Qiu, Y. L.
Wang, X. G.
Wang, X. Y.
Wu, C.
Zhang, L.
Zhang, S. N.
Solar and Stellar Astrophysics
High Energy Astrophysical Phenomena
Detection of stellar flares at hard X-ray is still rare at the current stage. A transient was recently detected by the hard X-ray camera, ECLAIRs onboard the SVOM mission at 11:39:01.2UT on 2025, January 09. Simultaneous monitor in the optical band on the ground by SVOM/GWAC and follow-up spectroscopy enable us to confirm that the transient is caused by a superflare on HD~22468, a RS CVn-type star. The bolometric energy released in the flare is estimated to be $\sim7.2\times10^{37}-1.7\times10^{38}\ \mathrm{erg}$. The hard X-ray spectra of the event at the peak can be reproduced by the ``apec'' model of a hot plasma with a temperature of $106^{+27}_{-22}$~MK. In the optical range, the H$α$ emission-line profile obtained at $\sim1.7$ hrs after the trigger shows a bulk blueshift of $-96\pm20\ \mathrm{km\ s^{-1}}$, which can be explained by either a chromospheric evaporation or a prominence eruption. The ejected mass is estimated to be $3.9\times10^{20}$ g for the evaporating plasma, and to be $3.2\times10^{21}\ \mathrm{g}<M_{\mathrm{p}}<8.8\times10^{21}\ \mathrm{g}$ for the erupted prominence.
title Multi-wavelength Study of A Superflare on RS CVn-type Star HD22468 Triggered at Hard X-ray by SVOM
topic Solar and Stellar Astrophysics
High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2601.16558