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Zeta Aur Stars
Posted: Tue Sep 29, 2015 4:51 pm
by Francois Teyssier
Une collection d'étoiles Zeta Aur
Zone H alpha [6400,6700]
R = 110000
22 Vul
- _22vul_20150901_873_full.png (21.8 KiB) Viewed 6003 times
31 Cyg
- _31cyg_20150801_908_full.png (23.68 KiB) Viewed 6003 times
32 Cyg
- _32cyg_20150801_897_full.png (23.41 KiB) Viewed 6003 times
Gam Per
- _gamper_20150920_888_full.png (21.52 KiB) Viewed 6003 times
Tau Per
- _tauper_20150920_904_full.png (21.48 KiB) Viewed 6003 times
VV Cep
- _vvcep_20150828_890_full.png (17.48 KiB) Viewed 6003 times
Zet Aur
- _zetaur_20150929_147_full.png (22.44 KiB) Viewed 6003 times
Il faudrait maintenant aller chercher le proche UV entre 3800 et 4000, c'est là que ça se passe ...
François
Re: Zeta Aur Stars
Posted: Wed Oct 07, 2015 11:46 am
by Peter Somogyi
Doing some near-UV captures of 31-Cyg, 32-Cyg, VV Cep - in 3843A - 4001A, I've found the 2400/mm quite usable in this region.
In the beginning sky was OK, one 10-minute exposure was flooded by signal:
- _31cyg_20151005_853_psomogyi.png (5.46 KiB) Viewed 5959 times
Then got some fog while 32-Cyg:
- _32cyg_20151005_864_psomogyi.png (6.02 KiB) Viewed 5959 times
Before and after 31/32 Cyg, taken VV Cep at the same wavelength (2nd is noisy) during the same night:
- _vvcep_20151005_809_psomogyi.png (6.71 KiB) Viewed 5959 times
And an earlier attempt [3629 - 3790] with 2400/mm, with some defocus at both end and signal loss at left side:
- _vvcep_20151003_851_psomogyi.png (5.36 KiB) Viewed 5959 times
But I was unable to identify these "reverse P-cygni" features above (couldn't find any line for them in VSpec - and Pickles is too low res), I'd appreciate explanation.
Peter
Re: Zeta Aur Stars
Posted: Mon Sep 26, 2016 11:42 pm
by Peter Somogyi
After 1 year, yesterday made a UV session (with some clouds flying by), allowing to do further 1-year compare.
31 cyg:
Basically identical, continuum differs for some reason.
32 cyg:
First I thought taken the wrong star. However, did take a Deneb and Del Cyg just for fun, and they are both different. Comparing to 31 Cyg also shows different characteristics.
Is such a big change expected?
Be aware that above spectra (each 2 x 10 exposures) are mostly noiseless.
Made a deeper experimental UV region for VV Cep, had to fix the old 2015 wavelength + simply forgot to apply instrumental response for that one.
Now here is the compare:
Interesting that the reverse P-Cyg profile peaks did not increase seriously in this region.
Finally, a change of VV Cep within this month:
Something changed at 3934A, what can it be?
Attaching the .zip file of new content with the fixed region of 2015.
Have fun!
Peter
Re: Zeta Aur Stars
Posted: Fri Oct 21, 2016 4:18 am
by Phil Bennett
Peter,
The inverse P Cygni lines in your UV spectrum of VV Cep are the higher Balmer lines (the deep absorption minimum is near line centre). Your spectrum shows, in order of decreasing wavelength:
H 2-11 3770.63 A
H 2-12 3750.15 A
H 2-13 3734.37 A
H 2-14 3721.94 A
H 2-15 3711.97 A
H 2-16 3703.85 A
H 2-17 3697.15 A
H 2-18 3691.55 A
H 2-19 3686.83 *missing* -- another absorption feature appears to be coincident
H 2-20 3682.81 A
H 2-21 3679.35 A probable
+ some possible higher Balmer lines.
Phil
Re: Zeta Aur Stars
Posted: Sat Oct 22, 2016 7:03 pm
by Peter Somogyi
Thank you Phil for the lines identification, there seem to be no surprise then.
Let me share the CaII region serie animated gif I have since september:
- VV Cep animation
- result.gif (99.12 KiB) Viewed 5551 times
Besides my flat handling changes (should cause low order humps) I can see a sudden inverse P Cyg extension appeared (radial velocities similar for both H7 and H8 here with CaII superponated), but it doesn't show any longterm trend. It's strong at +500 km/sec and weaker at +1000 km/sec.
Continuing with this region soon.
- Peter