spectro-aras.com

Update of Raman OVI equivalent width
The V curve in green (inversed scale)

François

Bonjour à tous, voici ma contribution à cette symbiotique .
Sincèrement.
Umberto

AG Dra, in the night 2016 07 16.
J. Guarro

Hi,

AG Dra on the night 2017 04 07.

Cheers, Joan.

A full commented spectrum, using Tim's PlotSpectra
Taken during last outburst (cool outburst), so Raman OVI very weak
François

Here is a commented (ignoring the Balmer lines to reduce clutter) spectrum using PlotSpectra of AG Dra from last night. Maybe someone could enlighten me on the significant lines to look for and how to interpret the strength or weakness of these lines as compared to François spectrum in outburst?
Thanks!
Forrest

Part of a VHIRES-MO spectrum (R=48000) + C11 telescope taken last night:

Raman O IV



Halpha



He I



He II



Christian Buil

Hi Woody

The giant of AG Dra is a K0-K3 giant of low metallicity. This is the reason why Fe lines do not appear

At low resolution, what can we do?

Measure Hb and HeII 4686
Let K = 0.534 * F(HeII)/F(Hb)
The temperature of the hot object can be estimated: T = 19.38*K^1/2 + 5.13 (in 10000 K unit)
This is a simplified Iijima's formula (1981), derived from Zanstra method

The ratio between HeI singlets and triplets (for instance 6678 and 5876) is a valuable indication of the electronic density

The flux of Raman OVI lines 6830 7085 (Raman scattering of O VI λ1032, 1038 A photons off neutral hydrogen) allows amateurs to "see" the farUV
The évolution of the flux of these lines will depend of the type of outburst ("cool" : they will nearly desappear "hot" : remain bright)
Interesting : the ratio F(6830)/F(7085). See Shore &al. (2010) : https://arxiv.org/abs/0912.1890

At higher resolution : lines profiles, radial velocity of the RG, ratio between the bue and red part of Raman OVI lines ...

Look at: http://www.astronomie-amateur.fr/Docume ... CE2016.pdf


All the best

François

Comparison of 11/04 and 14/04 observations of AG Peg (Halpha). No very significant variation (the telluric are removed for a better comparison) :



Christian Buil