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Re: V694 Mon revisted

PostPosted: Mon Jan 21, 2019 2:28 am
by James Ley
I was only able to record one acquisition of 300s before the clouds rolled in.
V694 Mon full 300s.png
V694 Mon full 300s.png (13.94 KiB) Viewed 962 times

I see the Hydrogen Balmer lines without p-cygni profiles but many metal lines with p-cygni profiles.
V694 Mon P-Cygni.png
V694 Mon P-Cygni.png (18.47 KiB) Viewed 962 times

AAVSO suggests continuing brightening, similar to 2016.
V694Mon AAVSO.png
V694Mon AAVSO.png (59.7 KiB) Viewed 962 times

Is V694 Mon in outburst?

Re: V694 Mon revisted

PostPosted: Mon Jan 21, 2019 6:17 pm
by Francois Teyssier
Hi James,
Yes, Balmer lines are in (almost) pre emission since october, with just a faint absorption at about -200 km/s
See information letter 2018-03, p. 88 :,
ATel 12231 with spectra obtained by Peter Somogyi and
I'm not conviced by the identification of He I lines 4922 and 5016 as stronger than Fe II. But unfortunately, we have no high res spectra for Hbeta region in november.
This is a peculiar state for this star. The optical outburst (luminosity) is clear from AAVSO data.
But the concept of outburst is unclear for this star which is in permanent outburst, with strong variations of the absorptions in Balmer lines with terminal velocities chnaging from ~ 1000 to 8000 km/s
Your spectrum in welcome in the database.

Monitoring of the fascinating star is recommended until spring


Re: V694 Mon revisted

PostPosted: Thu Jan 31, 2019 2:42 am
by James Ley
Thank you Francois for your kind words and encouragement.
Here is a spectrum that I took last night.
V694 Mon full.png
V694 Mon full.png (12.53 KiB) Viewed 885 times

This was 10 x 600s. That certainly increased the signal to noise ratio!
Do you think that these profiles suggest absorption of H-beta and H-alpha?
V694 Mon H-beta.png
V694 Mon H-beta.png (16.27 KiB) Viewed 885 times

V694 Mon H-alpha.png
V694 Mon H-alpha.png (13.34 KiB) Viewed 885 times

Considering once again your excellent diagram
V694Mon.PNG (89.64 KiB) Viewed 885 times

By definition, one will only see the emissions you show from the accretion disk if the disk is optically thin. Is it possible that, due to increased mass transfer, the disk has become optically thick (to H-alpha at least) and that the H-alpha emission is coming from further out and therefore is not absorbed by the jet? Does that make sense?

Re: V694 Mon revisted

PostPosted: Thu Feb 14, 2019 9:03 pm
by James Foster
Here is my most recent result for low resolution Alpy600 (Vis) and LISA (Ir) on V694 Mon:
I'll try to post my photometry data as I have been shooting this object every clear night with the C-11
and ST-8xme with Astrodon photometric filters.