Predicted outburst of the SN impostor PSN J12355216+2755560
ATel #16115; Dedov E. (SAO RAS), Sarkisyan A. (SAO RAS), Vinokurov A. (SAO RAS), Tatarnikov A. (SAI MSU), Spiridonova O. (SAO RAS)
on 3 Jul 2023; 15:39 UT
Credential Certification: Alexander Vinokurov (vinokurov@sao.ru)
Subjects: Optical, Transient
We report on an outburst of AT 2016blu in NGC 4559 galaxy in late-June predicted by Aghakhanloo et al. 2022 (arXiv:2212.09708).
Photometric observations were carried out from June 21 to June 28 using 6-m telescope of SAO RAS (BTA) equipped with Scorpio-2 focal reducer, 1-m telescope of SAO RAS (Zeiss-1000) and 2.5-m telescope of Caucasian Mountain Observatory of SAI MSU. Observed light curve demonstrates double-peaked form with the first maximum at June 23 and the second one at June 25. V-band magnitudes obtained with aperture photometry method. For calibration we used SDSS(DR16) data. Error values arise from insufficient number of stars for calibration and background uncertainties which are dominant factor for poor seeing (varies from 1.1 to 4 arcsec).
MJD | Telescope | V, mag
60116.91 | BTA | 17.36 ± 0.14
60117.86 | Zeiss-1000 | 16.70 ± 0.10
60118.82 | BTA | 16.41 ± 0.03
60119.81 | BTA | 17.33 ± 0.06
60120.81 | 2.5m CMO | 16.38 ± 0.10
60121.80 | BTA | 16.79 ± 0.09
60122.81 | BTA | 16.78 ± 0.03
60123.80 | BTA | 17.16 ± 0.04
For simultaneous spectroscopic observations we used the VPHG1200@540 grism on Scorpio-2 with spectral range 3650-7300 angstroms. The most notable features of the spectrum are Balmer series emission lines with Lorentzian-like profile. In spectrum there are also seen weak emission lines of He I and Fe II. Furthermore, hydrogen and helium lines show weak absorption components with increasing depth during the outburst evolution. In June 26 spectrum double-peak profile of absorptions with first peak at 5300 km/s and second peak at 2700 km/s relatively to emission component (measured for Hα and Hβ) is clearly seen.
