RT journal article
T1 Forbidden hugs in pandemic times: IV. Panchromatic evolution of three luminous red novae
A1 Pastorello, A.
A1 Valerin, G.
A1 Fraser, M.
A1 Reguitti, A.
A1 Elias-Rosa, N.
A1 Morales Garoffolo, Antonia Isabel
A2 Física Aplicada
K1 binaries
K1 close – stars
K1 individual: AT 2018bwo – stars
K1 individual: AT 2021blu – stars
K1 individual: AT 2021afy – stars
K1 winds
K1 outflows
AB We present photometric and spectroscopic data on three extragalactic luminous red novae (LRNe): AT 2018bwo, AT 2021afy, and AT 2021blu.AT 2018bwo was discovered in NGC 45 (at about 6.8 Mpc) a few weeks after the outburst onset. During the monitoring period, the transientreached a peak luminosity of 1040 erg s−1. AT 2021afy, hosted by UGC 10043 (∼49.2 Mpc), showed a double-peaked light curve, with the twopeaks reaching a similar luminosity of 2.1(±0.6) × 1041 erg s−1. Finally, for AT 2021blu in UGC 5829 (∼8.6 Mpc), the pre-outburst phase waswell-monitored by several photometric surveys, and the object showed a slow luminosity rise before the outburst. The light curve of AT 2021bluwas sampled with an unprecedented cadence until the object disappeared behind the Sun, and it was then recovered at late phases. The light curveof LRN AT 2021blu shows a double peak, with a prominent early maximum reaching a luminosity of 6.5 × 1040 erg s−1, which is half of that ofAT 2021afy. The spectra of AT 2021afy and AT 2021blu display the expected evolution for LRNe: a blue continuum dominated by prominentBalmer lines in emission during the first peak, and a redder continuum consistent with that of a K-type star with narrow absorption metal linesduring the second, broad maximum. The spectra of AT 2018bwo are markedly different, with a very red continuum dominated by broad molecularfeatures in absorption. As these spectra closely resemble those of LRNe after the second peak, AT 2018bwo was probably discovered at the verylate evolutionary stages. This would explain its fast evolution and the spectral properties compatible with that of an M-type star. From the analysisof deep frames of the LRN sites years before the outburst, and considerations of the light curves, the quiescent progenitor systems of the threeLRNe were likely massive, with primaries ranging from about 13 M  for AT 2018bwo, to 14+4−1 M  for AT 2021blu, and over 40 M  for AT 2021afy.
PB EDP Sciences
SN 1432-0746
YR 2023
FD 2023
LK http://hdl.handle.net/10498/31892
UL http://hdl.handle.net/10498/31892
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 13-nov-2026