Liverpool Telescope Spectroscopy of the Nova Eruption from V392 Persei as it exits Sun constraint

ATel #11846; M. J. Darnley (LJMU)
on 13 Jul 2018; 13:07 UT
Credential Certification: Matt Darnley (M.J.Darnley@ljmu.ac.uk)

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Here we report the first post-Sun constraint Liverpool Telescope spectrum of the 2018 classical nova eruption from the known dwarf nova V392 Per (see, ATel #11588, #11590, #11594, #11601, #11605, #11617, and #11647 for further details; also see CBAT, ARAS, and Darnley & Starrfield 2018).

The spectrum was collected with the FRODOSpec (Barnsley et al. 2012 instrument on the LT on 2018 July 13.21 UT. We utilised the low resolution mode (R=2600, blue arm 3900-5700Å - R=2200, red arm 5800-9400Å) of FRODOSpec, with an integration time of 3×180s for both arms.

The spectrum was collected at a high airmass (>2), may have suffered from acquisition issues, and there was some thin cirrus around. As such, the throughput in the blue arm of the spectrum was very poor, therefore we only report on the red arm (in which the S/N was also low).

Only three emission lines are visible in the red arm, Hα, and He I (6678 and 7065Å). The profile of all three lines are similar, but they are all remarkably different from those reported in ATel #11601.

The line profiles show a narrow (~50 km/s) and bright emission spike at approximately the rest wavelength of each line, bracketed on either side by fainter but broad emission bumps. For Hα, the blueward and redward bumps are shifted by ~±1750 km/s and have a FWHM of ~1600 km/s. The blueward bump is ~2/3 the height of the redward bump (which is ~half the height of the central narrow peak).

As V392 Per exits the Sun, follow-up observations, particularly spectroscopy, are strongly encouraged. The first of a series of Swift observations are planned to begin on 2018 July 20.