V Sge
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Re: V Sge
Fresh result from this Friday evening, on top of this compilation:
Blue part have the same exposures, H-alpha was scaled fully differently.
As for tellurics, would be nice to know a standard method to follow here (2 methods I'm aware: one is to have a ref.star - tried but result is contaminated by noise and H-alpha middle, other is synthethic reproduction - haven't tried yet). Sending uncalibrated (left part of H-alpha on 20160723.839 affected the most).
- Peter
Blue part have the same exposures, H-alpha was scaled fully differently.
As for tellurics, would be nice to know a standard method to follow here (2 methods I'm aware: one is to have a ref.star - tried but result is contaminated by noise and H-alpha middle, other is synthethic reproduction - haven't tried yet). Sending uncalibrated (left part of H-alpha on 20160723.839 affected the most).
- Peter
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Re: V Sge
All that is very good
Should be interesting to link the observations to phase
I found :
Ephemeris for the primary minimum by
Mader & Shafter (1997): T(min) = 2,437,889.913(5) + 0.514195(4) x E
François
Should be interesting to link the observations to phase
I found :
Ephemeris for the primary minimum by
Mader & Shafter (1997): T(min) = 2,437,889.913(5) + 0.514195(4) x E
François
François Teyssier
http://www.astronomie-amateur.fr
http://www.astronomie-amateur.fr
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Re: V Sge
Thank you Francois for the formula and author names (allowed to google for article), now I've been able to create that chart:
Continuum supposed to be at 1, but scaled to 0.05 for H-alpha, 0.12 for H-beta and 0.07 for HeII 4686 on the above graphs (and continuum is added to the phase in the interval of [0..1]).
Applied shift as the absolute period.
Using all of my spectra (including a very noisy one available at blue only) + used Francois's observation on 07.14 (asdb_vsge_20160714_036), rectified continuum on it in both blue and red separately, and did a gauss filter 5 on it so now matches well by both SNR and resolution. (Unfortunately, I was able to download only this spectrum for extending my serie.)
I think the formula works well (couldn't go to sleep without trying...), was fitting the graph sizes to this:
http://iopscience.iop.org/article/10.10 ... /fulltext/
http://iopscience.iop.org/article/10.10 ... 6.fg1.html
We are somewhat different I think, but the period still seem to apply.
More spectra should be welcome I think, especially from the missing middle phases... (might require a proper scheduling)
Cheers,
Peter
Continuum supposed to be at 1, but scaled to 0.05 for H-alpha, 0.12 for H-beta and 0.07 for HeII 4686 on the above graphs (and continuum is added to the phase in the interval of [0..1]).
Applied shift as the absolute period.
Using all of my spectra (including a very noisy one available at blue only) + used Francois's observation on 07.14 (asdb_vsge_20160714_036), rectified continuum on it in both blue and red separately, and did a gauss filter 5 on it so now matches well by both SNR and resolution. (Unfortunately, I was able to download only this spectrum for extending my serie.)
I think the formula works well (couldn't go to sleep without trying...), was fitting the graph sizes to this:
http://iopscience.iop.org/article/10.10 ... /fulltext/
http://iopscience.iop.org/article/10.10 ... 6.fg1.html
We are somewhat different I think, but the period still seem to apply.
More spectra should be welcome I think, especially from the missing middle phases... (might require a proper scheduling)
Cheers,
Peter
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- Contact:
Re: V Sge
Very nice !
I updated the database with Tim's spectra
François
I updated the database with Tim's spectra
François
François Teyssier
http://www.astronomie-amateur.fr
http://www.astronomie-amateur.fr
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Re: V Sge
Including now Tim's spectra (0724.004, 0727.024), revealing the middle phase:
This time made a local continuum fit around H-alpha, too.
Did set the continuum to 0-level this time, considering the skew is misleading.
I can reproduce the above diagrams in postscript when necessary (fully batched via IRAF now).
As before, was using JD-MID (without any HJD conversion - could introduce just 8.3 minute skew).
I think the color composite of the above should also be interesting:
Look at the differences of HeII 4686 and H-alpha on top and bottom (should be real, I think).
- Peter
Notes:
- fixed my own asdb_vsge_20160730_011.fit JD-MID locally, forgot to handle when applied per-exposure calibration manually (visible as JD-OBS being too close to JD-MID)
- colors yet need more manual effort, can't plot colors in .ps via IRAF somehow
- used 4686, 4861.33, 6562.7 A for the zero references of velocity (couldn't find more accurate wavelength for He II 4686), maybe the He II could be tuned further
- I can publish IRAF the commands on another forum when someone is interested
EDIT: looking at differences on the color diagram H-alpha being too far from other features (also in time), but the eShel one matching all 3 features on 07.14 too well, puts up a suspect here some assumption being wrong. This needs more investigation.
This time made a local continuum fit around H-alpha, too.
Did set the continuum to 0-level this time, considering the skew is misleading.
I can reproduce the above diagrams in postscript when necessary (fully batched via IRAF now).
As before, was using JD-MID (without any HJD conversion - could introduce just 8.3 minute skew).
I think the color composite of the above should also be interesting:
Look at the differences of HeII 4686 and H-alpha on top and bottom (should be real, I think).
- Peter
Notes:
- fixed my own asdb_vsge_20160730_011.fit JD-MID locally, forgot to handle when applied per-exposure calibration manually (visible as JD-OBS being too close to JD-MID)
- colors yet need more manual effort, can't plot colors in .ps via IRAF somehow
- used 4686, 4861.33, 6562.7 A for the zero references of velocity (couldn't find more accurate wavelength for He II 4686), maybe the He II could be tuned further
- I can publish IRAF the commands on another forum when someone is interested
EDIT: looking at differences on the color diagram H-alpha being too far from other features (also in time), but the eShel one matching all 3 features on 07.14 too well, puts up a suspect here some assumption being wrong. This needs more investigation.
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Re: V Sge
Hi all, two observations coordinated with Umberto Sollecchia. I took V photometry (Mak90, SXV-H9, Baader V filter) and mid-res spectroscopy (Lhires III 1200). Umberto took low-res spectrum with Alpy 600. We started about at the same time in order to have simultaneous data.
Photometric data:
Mak 90
V Baader filter
SXV-H9 CCD camera
Astroart 6 software
ApassV magnitude of field stars
Spectrophotometric method uses:
V filter specific transmission curve
Mean zero point calculated with some CALSPEC profiles convolved with V filter curve
Mean V magnitude during the spectra integration
The V mag curve on 3 august night (I think we observed during one of the brightness maxima):
Low-res profile:
Mid-res profile in the h-alpha region:
H-alpha line heliocentric radial velocity:
A previous attempt made on 30 july (not exactly synchronized), when the star brightness was decreasing.
V mag curve:
Low-res profile animation with V photometry (five profiles composed of 4 x 360s subexp.)
Mid-res profile in the h-alpha region:
H-alpha line heliocentric radial velocity:
I wonder if the spectrophotometric method used is a better choice with so quickly variable targets, compared to using direct methods such as large slit observations. Any suggestion in this regard is welcome.
Paolo
Photometric data:
Mak 90
V Baader filter
SXV-H9 CCD camera
Astroart 6 software
ApassV magnitude of field stars
Spectrophotometric method uses:
V filter specific transmission curve
Mean zero point calculated with some CALSPEC profiles convolved with V filter curve
Mean V magnitude during the spectra integration
The V mag curve on 3 august night (I think we observed during one of the brightness maxima):
Low-res profile:
Mid-res profile in the h-alpha region:
H-alpha line heliocentric radial velocity:
A previous attempt made on 30 july (not exactly synchronized), when the star brightness was decreasing.
V mag curve:
Low-res profile animation with V photometry (five profiles composed of 4 x 360s subexp.)
Mid-res profile in the h-alpha region:
H-alpha line heliocentric radial velocity:
I wonder if the spectrophotometric method used is a better choice with so quickly variable targets, compared to using direct methods such as large slit observations. Any suggestion in this regard is welcome.
Paolo
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Re: V Sge
Paolo, Umberto, it's very nice, I'm also having some more spectra on this in my queue. I'd recommend sending all in a form of serie, as I can see at least the HeII 4686 looks having features shifting every 20 minute!
Cheers,
Peter
Cheers,
Peter
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Re: V Sge
Paolo & Umberto:
You made a good team.
The result is eloquent, is very nice, congratulations !!
Un forte abbraccio, Joan.
You made a good team.
The result is eloquent, is very nice, congratulations !!
Un forte abbraccio, Joan.
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- Joined: Thu Sep 29, 2011 10:51 pm
Re: V Sge
Peter, Joan, thank you for your comments! The target is very interesting and deserves a frequent monitoring. Following the single profiles animation.
Low-res (360s resolution):
Mid-res (960s resolution, some changes in the blue side of the line):
We do need larger telescope apertures...
Paolo
Low-res (360s resolution):
Mid-res (960s resolution, some changes in the blue side of the line):
We do need larger telescope apertures...
Paolo
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Re: V Sge
Peter, Joan, je vous remercie beaucoup d'avoir partagé notre travail.
Salutations
Umberto
Salutations
Umberto