Zeta Aur Stars

VV Cep 2017-2019 Campaign
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Francois Teyssier
Posts: 1520
Joined: Fri Sep 23, 2011 1:01 pm
Location: Rouen
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Zeta Aur Stars

Post by Francois Teyssier »

Une collection d'étoiles Zeta Aur
Zone H alpha [6400,6700]
R = 110000

22 Vul
_22vul_20150901_873_full.png
_22vul_20150901_873_full.png (21.8 KiB) Viewed 5291 times
31 Cyg
_31cyg_20150801_908_full.png
_31cyg_20150801_908_full.png (23.68 KiB) Viewed 5291 times
32 Cyg
_32cyg_20150801_897_full.png
_32cyg_20150801_897_full.png (23.41 KiB) Viewed 5291 times
Gam Per
_gamper_20150920_888_full.png
_gamper_20150920_888_full.png (21.52 KiB) Viewed 5291 times
Tau Per
_tauper_20150920_904_full.png
_tauper_20150920_904_full.png (21.48 KiB) Viewed 5291 times
VV Cep
_vvcep_20150828_890_full.png
_vvcep_20150828_890_full.png (17.48 KiB) Viewed 5291 times
Zet Aur
_zetaur_20150929_147_full.png
_zetaur_20150929_147_full.png (22.44 KiB) Viewed 5291 times
Il faudrait maintenant aller chercher le proche UV entre 3800 et 4000, c'est là que ça se passe ...

François
Peter Somogyi
Posts: 420
Joined: Sun Jul 13, 2014 8:56 am

Re: Zeta Aur Stars

Post 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
_31cyg_20151005_853_psomogyi.png (5.46 KiB) Viewed 5247 times
Then got some fog while 32-Cyg:
_32cyg_20151005_864_psomogyi.png
_32cyg_20151005_864_psomogyi.png (6.02 KiB) Viewed 5247 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
_vvcep_20151005_809_psomogyi.png (6.71 KiB) Viewed 5247 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
_vvcep_20151003_851_psomogyi.png (5.36 KiB) Viewed 5247 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
Peter Somogyi
Posts: 420
Joined: Sun Jul 13, 2014 8:56 am

Re: Zeta Aur Stars

Post 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:
31cyg_cmp_2015vs2016.png
Basically identical, continuum differs for some reason.

32 cyg:
32cyg_cmp_2015vs2016.png
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:
vvcep_3631A_cmp_2015vs2016.png
Interesting that the reverse P-Cyg profile peaks did not increase seriously in this region.

Finally, a change of VV Cep within this month:
vvcep_3900_cmp_month.png
Something changed at 3934A, what can it be?

Attaching the .zip file of new content with the fixed region of 2015.
vvcep_3132cyg_uv_20160925_pso.zip
(28.51 KiB) Downloaded 340 times
Have fun!
Peter
Attachments
vvcep_3132cyg_uv_20160925_pso.zip
(28.51 KiB) Downloaded 356 times
Phil Bennett
Posts: 10
Joined: Mon Aug 24, 2015 7:40 am

Re: Zeta Aur Stars

Post 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
Peter Somogyi
Posts: 420
Joined: Sun Jul 13, 2014 8:56 am

Re: Zeta Aur Stars

Post 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
VV Cep animation
result.gif (99.12 KiB) Viewed 4839 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
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