Une collection d'étoiles Zeta Aur
Zone H alpha [6400,6700]
R = 110000
22 Vul
31 Cyg
32 Cyg
Gam Per
Tau Per
VV Cep
Zet Aur
Il faudrait maintenant aller chercher le proche UV entre 3800 et 4000, c'est là que ça se passe ...
François
Zeta Aur Stars
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Zeta Aur Stars
François Teyssier
http://www.astronomie-amateur.fr
http://www.astronomie-amateur.fr
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Re: Zeta Aur Stars
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: Then got some fog while 32-Cyg: Before and after 31/32 Cyg, taken VV Cep at the same wavelength (2nd is noisy) during the same night: And an earlier attempt [3629 - 3790] with 2400/mm, with some defocus at both end and signal loss at left side: 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
In the beginning sky was OK, one 10-minute exposure was flooded by signal: Then got some fog while 32-Cyg: Before and after 31/32 Cyg, taken VV Cep at the same wavelength (2nd is noisy) during the same night: And an earlier attempt [3629 - 3790] with 2400/mm, with some defocus at both end and signal loss at left side: 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
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Re: Zeta Aur Stars
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
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
- Attachments
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- vvcep_3132cyg_uv_20160925_pso.zip
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Re: Zeta Aur Stars
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
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
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Re: Zeta Aur Stars
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:
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
Let me share the CaII region serie animated gif I have since september:
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