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Re: Nova Sgr = PNV J18365700-2855420

Posted: Sat Mar 21, 2015 12:42 am
by Malcolm Locke
My spectrum of the H_beta region from 2015/03/20.634.

0.4m SCT, L200 @ 1800 l/mm, 24um slit, SBIG ST8. 12 x 300 seconds, R ~
9000.

No photometry but I made a visual estimate of 4.9. Considerable change
since the last spectrum in ARAS.
nova_sgr_2015_2_h_beta_region.png

Re: Nova Sgr = PNV J18365700-2855420

Posted: Sat Mar 21, 2015 7:14 am
by Jon
Here is a 3 hr spectrum from 19-3-2015, of the region 6800-7160, as requested by Steve Shore.
_novasgr_20150319_664_JPowles.png
_novasgr_20150319_664_JPowles.png (7.77 KiB) Viewed 7748 times
The OI line at 7003 and the CI line complex at 7115 are clearly visible, although the 7003 line is obscured by the heavy telluric lines. I've had a go at removing them, using the H2O tool in vspec and using the spectrum of the reference star I'm using (Phi Sgr). The tellrric-corrected spectrum is offset below, with a Gaussian filter applied to remove the artifacts.
6800-7200.png
6800-7200.png (69.45 KiB) Viewed 7748 times

Re: Nova Sgr = PNV J18365700-2855420

Posted: Mon Mar 23, 2015 6:24 pm
by Francois Teyssier
Comparison of Jonathan Powles and Jim Edlin spectra
Impressive evolution in less than one day :
The ejecta is turning thin.
Have a look on Fe II absorptions.
NovaSgr2015-2_20150322-744_20150323-489.png
NovaSgr2015-2_20150322-744_20150323-489.png (37.52 KiB) Viewed 7727 times
Congratulation for these nice and interesting spectra


François Teyssier

Re: Nova Sgr = PNV J18365700-2855420

Posted: Tue Mar 24, 2015 12:09 pm
by umberto sollecchia
Hi all,

0bserved spectrum of nova . All data are reported on graph frame.
Due to very low altitude of target above the horizon and irregular clouds presence it is possible that the continuum is not well corrected.
Profilo-Nova_sgr_2015-#2.jpg
Profilo-Nova_sgr_2015-#2.jpg (54.15 KiB) Viewed 7692 times
Umberto

Re: Nova Sgr = PNV J18365700-2855420

Posted: Wed Mar 25, 2015 6:03 am
by Francois Teyssier
Well done Unberto
Nice result at such an altitude
Of course, the spectrum is welcome in the data base

Regards,

François

Re: Nova Sgr = PNV J18365700-2855420

Posted: Fri Mar 27, 2015 4:48 am
by James Edlin
Hi all,

Clear night this morning. Spectrum of Nova Sag #2 with CDK 24 (0.61m) - LISA - Atik 460 ccd. Had to reduce exposure to 15 sec so as not to saturate the H alpha line. Total 6 min (15 sec x 24). Prior spectrum poor quality due to heavy haze and clouds.

Jim

Re: Nova Sgr = PNV J18365700-2855420

Posted: Sun Apr 05, 2015 5:04 am
by Malcolm Locke
I remember V1369 Cen going through a very similar re-brightening after the first maximum, so I thought I would plot the two light curves together.

They are so far remarkably similar. Nova Sgr is maybe a little slower in the oscillations, it will be interesting to see if the similarities continue over a longer period.
nova_sgr_2015_2_v1369_cen_lightcurve.png
nova_sgr_2015_2_v1369_cen_lightcurve.png (17.96 KiB) Viewed 7586 times

Re: Nova Sgr = PNV J18365700-2855420

Posted: Mon Apr 06, 2015 6:24 pm
by Christian Buil
Here a eShel spectrum of nova Sgr 2 taken the March 6, 2015(R=11000, 200-mm f/5 Newton telescope):

Image

A comparison of the eShel spectrum taken 17 March (a detail of the blue part):

Image

and now may lasted spectrum of the same region:

Image

(note apparition of numerous relatively fine lines in near-UV).

A close look of sodium doublet region (March 1.66) - eShel spectrograph at R = 11000:

Image

The same spectral domain taken with the VHIRES MO spectrograph at R = 50000 (T200 mm telescope)
(see http://www.astrosurf.com/buil/vhires/demo3.htm):

Image

Note the very hight contrast of interstellar Na lines with the increase of spectral resolution.

A panorama of nova spectrum part at very high resolution (R = 50000 - thanks to the magnitude of these exceptional objet!):

Image

Image

Image

Image

Image

Image

Christian

Re: Nova Sgr = PNV J18365700-2855420

Posted: Mon Apr 06, 2015 10:52 pm
by Paolo Berardi
Wow Christian, what a series of valuable observations! Nova Del 2013 was also bright and better placed in the sky for us. What I see now really represents a major step forward!

Paolo

Re: Nova Sgr = PNV J18365700-2855420

Posted: Tue Apr 07, 2015 5:25 pm
by Christian Buil
A Alpy600 (R=650) spectrum of the nova taken the 7.15/04/2015 (20 x 20 sec. exposure, T200 F/5 telescope):

Image

Christian B