Presentation #346.04 in the session Cataclysmic Variables, Novae, and Symbiotic Stars — iPoster Session.
V1674 Her (Nova Her 2021) was discovered in outburst on 2021 June 12 and reached a peak brightness of V ~ 6. It then declined extremely rapidly falling 2 magnitudes in 1.2 days. It was followed at high cadence by a slew of ground and space based observatories with numerous publications ensuing. These observations found that in addition to the fastest decline on record, it was an ONe type nova exhibiting strong forbidden Ne emission lines, and it exhibited a 501 s oscillation that suggested that the outburst occurred in an intermediate polar system. Moreover, the ejection velocities were of the order of 6000 km/s. We have continued to monitor it as it returned to quiescence and will present the optical spectra collected for this nova, plus any new data at other wavelengths, that we obtain after the submission of this abstract. Our optical data have been collected on 22 epochs to date at spectral resolutions ranging from 1700 to 130,000 with facilities of the MDM, MMT, and LBT observatories. Our latest spectrum, obtained with the MDM 2.4-m Hiltner telescope and OSMOS spectrograph (2022 March 27 UT), after it emerged from solar conjunction, show a dramatic change in that the forbidden lines have disappeared and He II 4686 Ang is the strongest emission line in the spectrum superposed on a blue continuum. We will discuss the implications of this change. We are grateful to all the facilities for their support of observing time.