Liverpool Telescope spectral monitoring of Nova Delphini 2013 reveals dramatic changes in the Hydrogen Balmer lines
ATel #5300; M. J. Darnley (LJMU), M. F. Bode (LJMU)
on 20 Aug 2013; 09:01 UT
Credential Certification: Matt Darnley (M.J.Darnley@ljmu.ac.uk)
Since confirming the classical nova nature of Nova Del 2013 (ATel #5279) the Liverpool Telescope (LT) has been monitoring the outburst with approximately hourly cadence (weather/moon permitting). The FRODOSpec instrument on the LT has been deployed in its lower resolution mode (R~2400) with wavelength coverage from 3800-10000 Angstroms.
Pronounced P Cygni profiles were present in the Hydrogren Balmer lines in the spectra of Nova Del 2013 from the first LT observations (9:22pm UTC 14th August 2013) and have been reported by a number of other observers (e.g. ATel #5282, #5288, #5291, #5295, #5297).
The Balmer series P Cygni profiles were still present in LT spectra taken at 2:53am (UTC) 19th August 2013.
However, an LT spectrum of Nova Del 2013 taken at 22:36pm (UTC) 19th August 2013 revealed that the Hydrogren Balmer series P Cygni profiles have all but disappeared. That is, the depth of the absorption component has reduced to the approximate level of the continuum. Subsequent LT spectra have confirmed this change.
P Cygni profiles are however still clearly present in Fe II, He I and O I lines.
Follow-up observations at all frequencies are strongly encouraged.