Nova Sgr = PNV J18365700-2855420

[Joan Guarro Flo]

Hi:
The Nova Sgr#2 2015 in the last night.

J.Guarro.

[Terry Bohlsen]

My first spectra of this nova. Taken with a LISA on a C11 scope. It is very bright still with a V mag of 5.1
Spectra flux callibrated.

[Joan Guarro Flo]

Hello:

Small variations in Nova Sgr 2015 # 2.

J.Guarro

[Robin Leadbeater]

The new broad feature at ~4650A is also seen very clearly in a Star Analyser spectrum take by Rob Kauffman 14th May
https://groups.yahoo.com/neo/groups/sta ... sages/3774

Does anyone know what is causing it?

Robin

[Martin Dubs]

Hi Robin,

this looks similar to NovaDel2013, where about a month after peak magnitude this line appeared also, as can be seen from this animation, basaed on spectra from the ARAS database http://www.astrosurf.com/aras/Aras_Data ... l-2013.htm:

animation of flux calibrated spectra of NovaDel2103

@NovaDel_long2_.gif (576.22 KiB) Viewed 10018 times

Notice that the flux scale is logarithmic, quite useful for the spectra with large variation in flux. Robs asssignment to the NIII line at 4638A seems reasonable, maybe Francois can tell more about it.

Regards, Martin

[Francois Teyssier]

-

Robs asssignment to the NIII line at 4638A seems reasonable, maybe Francois can tell more about it.

That's right
This is the 'N flash'. A blend of NIII/CIII from 4640 to 4660
Ionization is increasing as the ejecta becomes thin for UV.
In the red edge of the blend will appears He II 4686
See http://www.astrosurf.com/aras/novae/Nova2013Del-2.html
Spectrum of 05-09-2013

This blend also appears in C.V. in outburst.

François

[Christian Buil]

An eShel spectrum (R=11000) on a 8-inch Newton telescope (10 x 3 min exposure) the 18.121 / 05 / 2015:



and some details:









Christian B

[Olivier GARDE]

An eshel spectrum taken last night.
4 exposures of 10 minutes each.



detail on order 34 (H alpha)


detail on order 46 (H Beta)

[Christian Buil]

An ancient unpublihed VHIRES-MO spectrum of nova Sgr 2015 #2 (24.06 / 04 / 2015):



Christian

[Christian Buil]

An eShel spectrum taken the 17.9/09/2015 (V=9):



Detail of Halpha region for the same date:



Note evolution of Halpha profile at high resolution on a eShel spectrum taken the 23.9/06/2015:



Alpy600 spectrum taken the 24.9/06/2015 (V=11 -> very fast decrease of the brightness -> cloud dust around the nova):



Christian