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I've just finished a short run (clouds) on del Ori and, as the attached composite plot shows, there appears to be a dramatic change in the continuum. I realise that the binary companion is drastically affecting the line profiles but had not expected the continuum to change so much ... if it is genuinel ... and I'm not aware of any reduction changes that could be responsible. Maybe Tony and Noel can comment on this?

Cheers,
Bernard

_________________
Quicquid Nitet Notandum

Hi Bernard:

This is very unlikely to be due to the stars. Even during an eclipse (only ~10% anyway), the colours of the stars are not different enough to account for this huge change. I suspect something instrumental, e.g. guiding on a particular part (wavelength) of a refracted image relatively low in the sky. Or maybe a different flat-field lamp or illumination?

The spectra are really nice, though, apart from that!

Cheers, Tony

From: Bernard Heathcote (fg-spek-convento@vds-astro.de)
Sent: Monday, December 17, 2012 9:15 AM
To: fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)
Subject: [fg-spek] Re: Request for observations of the 2mag star delta Orionis




I've just finished a short run (clouds) on del Ori and, as the attached composite plot shows, there appears to be a dramatic change in the continuum. I realise that the binary companion is drastically affecting the line profiles but had not expected the continuum to change so much ... if it is genuinel ... and I'm not aware of any reduction changes that could be responsible. Maybe Tony and Noel can comment on this?

Cheers,
Bernard



Quicquid Nitet Notandum

_________________
Tony Moffat

Hi Tony,

I?ve been reprocessing the spectra (instead of being in bed!) and found that there was some, as yet unknown, problem with the automatic atmospheric correction in my initial run. Tonight?s spectral continuum now overlays the earlier ones. I will post a corrected composite plot tomorrow ... and do apologise for the false alarm!

Cheers,
Bernard


From: Tony Moffat (fg-spek-convento@vds-astro.de)
Sent: Tuesday, December 18, 2012 1:42 AM
To: fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)
Subject: [fg-spek] Re: Request for observations of the 2mag star delta Orionis




Hi Bernard:

This is very unlikely to be due to the stars. Even during an eclipse (only ~10% anyway), the colours of the stars are not different enough to account for this huge change. I suspect something instrumental, e.g. guiding on a particular part (wavelength) of a refracted image relatively low in the sky. Or maybe a different flat-field lamp or illumination?

The spectra are really nice, though, apart from that!

Cheers, Tony

From: Bernard Heathcote (fg-spek-convento(==>)vds-astro.de ([email]fg-spek-convento(==>)vds-astro.de[/email]))
Sent: Monday, December 17, 2012 9:15 AM
To: fg-spek-convento(==>)vds-astro.de ([email]fg-spek-convento(==>)vds-astro.de[/email]) (fg-spek-convento(==>)vds-astro.de ([email]fg-spek-convento(==>)vds-astro.de[/email]))
Subject: [fg-spek] Re: Request for observations of the 2mag star delta Orionis




I've just finished a short run (clouds) on del Ori and, as the attached composite plot shows, there appears to be a dramatic change in the continuum. I realise that the binary companion is drastically affecting the line profiles but had not expected the continuum to change so much ... if it is genuinel ... and I'm not aware of any reduction changes that could be responsible. Maybe Tony and Noel can comment on this?

Cheers,
Bernard



Quicquid Nitet Notandum



Tony Moffat





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_________________
Quicquid Nitet Notandum

Here's an example spectrum of delta Ori I acquired three nights ago. The spectrum is only wavelength calibrated and cleaned of tellurics. It would appear that I'd be best served to purchase the 1800 l/mm grating in order to increase wavelength coverage. As I have an extra grating drawer for the LHiRes III I'm thinking of just ordering a grating from Optometrics. I notice they offer Aluminum/Magnesium/Fluoride overcoating. Should I have that done as well? Thanks!

Beautiful spectrum, Mike! Not sure about which grating you do need, depending on the coverage desired. For del Ori we are requesting H-alpha and HeI 6678 as a minimum. If you can get more, especially at shorter wavelengths (plus HeI 10830), so much the better, though. I can?t say anything about these possible overcoatings. Unless someone else comes forward with some wise words, I guess you?ll have to rely on the advice of the manufacturer combined with the use you need.

Cheers, Tony

From: Mike Potter (fg-spek-convento@vds-astro.de)
Sent: Monday, December 17, 2012 11:03 AM
To: fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)
Subject: [fg-spek] Re: Request for observations of the 2mag star delta Orionis




Here's an example spectrum of delta Ori I acquired three nights ago. The spectrum is only wavelength calibrated and cleaned of tellurics. It would appear that I'd be best served to purchase the 1800 l/mm grating in order to increase wavelength coverage. As I have an extra grating drawer for the LHiRes III I'm thinking of just ordering a grating from Optometrics. I notice they offer Aluminum/Magnesium/Fluoride overcoating. Should I have that done as well? Thanks!

_________________
Tony Moffat

Hi Tony:

The question, then, is whether the wavelength coverage shown in the plot is sufficient for your purposes. I was mostly concerned with being able to properly fit the continuum on either side of the wings of each of the absorption features since each is close to the edges of the chip. While I do plan ultimately to add an 1800 line grating, if the coverage shown in the plot is sufficient I will likely hold off for now. Shifting the "window" 5 or 10 Angstroms is also a possibility. What do you think?

Mike

Hi Mike,

The spectrum looks great, and we should be able to work with the setup you have. The higher resolution is probably preferable. If you are too worried about it, focus on one of the lines, and that will still be useful. Setting up a new grating in the middle of the campaign may just cause headaches and frustration, and we should have fun with the science!

Cheers,

Noel

Hi all,

I received an email from Rusty Harvin, who is an expert with delta Ori, and he mentioned a few interesting things with the system.

Rusty writes: "I've become convinced that the secondary star in the central binary of delta Orionis A is a beta Cephei variable... Somewhere I've gotten an amplitude of about 30 millimag for this variation. Note that 30 mmag is one-fourth of the depth of primary eclipse, which around 120 mmag.

I'm writing to point out that photometrically beta Cephei stars have periods of 2-6 hours and amplitudes of a few hundredths of a mag. Hopefully, your MOST photometry time coverage will be dense enough to be able to cover this range of (possible) periods to either rule in or rule out a beta Cephei star in this system. (I'd guess it could also be a slow B pulsator with a longer period.)

Also note for your spectroscopic analysis, that beta Cephei stars are radial velocity pulsators."

This means that high S/N spectroscopy may allow us to prove/disprove the nature of the star. The MOST photometry (if I remember correctly for the timing) will likely find the period(s), and the new spectroscopy can help us identify radial/nonradial modes of pulsation in the system.

Keep observing, the data posted look great!

Clear skies,

Noel

Hi all,
cloudy weather last night over Montpellier south of France. Hopefully targets are brights, both principal and reference star, and some spectra are not so bad.
http://www.astrosurf.com/garrel/webdelori18122012/
http://gabalou.canalblog.com/archives/2 ... 54217.html


Same story tonight, hope same endings.
Cheers
Thierry   

2012/12/17 Noel Richardson <fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)>

_________________
Thierry Garrel
Observatoire de Fontcaude, Montpellier, France
SpectroBlog http://gabalou.canalblog.com/

Hi Thierry,

The spectra look great. Keep them coming! Best of luck with the weather!

Cheers,

Noel

Comparison of two echelle spectra (eShel spectrograph) on
a Celestron 9 taken the Dec. 16.04 and the Dec. 17.94 (short exposures because bad weather !).

The telluric lines are removed and continuum rectified to unity (ISIS
processing). Note the spectral shift for the two date (meeasured to
about 105 km/s). Note also presence of interstellar yellow doublet lines,
not affected by star radial velocity.

Here some part of echelle spectra:

next echelle spectra sample...

Christian Buil

New observations are available on http://gabalou.canalblog.com/archives/2 ... 54217.html

Echelle spectra from 17/12 to 20/12. Weather in south of France is not very cooperative and won't be for the next days.

_________________
Thierry Garrel
Observatoire de Fontcaude, Montpellier, France
SpectroBlog http://gabalou.canalblog.com/

No clear nights in southern Australia since 18 Dec

Cheers, Bernard

_________________
Quicquid Nitet Notandum

Hello,

now here you see a part of my echellespektrum from delta ori, in the adnex, you can download the complete echellespektrum

berthold

Hello,

now you see part from an echellespectrum of del_ori from 19.910/12/2012.

The pink one is the dried spectrum

berthold

I start my observations aiming the scope to delta orionis and let it do, ccd in acquisition. Sometimes, the cloud cover is thin or a rift for a few minutes allow signal to be strong enough to produce a spectra of good snr.  Yesterday i was observing for a while when i realised it was raining, that the limit of the method for sure.
 These stars are very bright. Del ori and ref star bet eri are visible on the guiding camera all along even during worse conditions. More observations should be possible, don't wait for optimal conditions, go for data and watch out for rain...
Thierry.

2012/12/21 Bernard Heathcote <fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)>

_________________
Thierry Garrel
Observatoire de Fontcaude, Montpellier, France
SpectroBlog http://gabalou.canalblog.com/

My latest observatin (20.812 december) and comparison with
most recents Castanet obs. observation.

See also the synthese page (and for download): http://www.astrosurf.com/buil/campaign/deltaori/obs.htm

Christian B.

I got this del ori profile last night. Looks like it might becoming active.

Hi Keith:

Wow, this looks really interesting. Please excuse me for asking if this is the right star! (beta Ori comes to mind when I see the emission
in H-alpha....) Assuming that it is del Ori (!), then this surely has to be narrow H-alpha emission intrinsic to del Ori and not a spectrum near quadrature
with two pure-absorption components spread apart in RV and thus showing double lines. But the secondary is quite a bit fainter, so this would be unlikely, although maybe it?s the 3rd (brighter) component, which does not participate in the 5.7d orbit (?) However, if due to double lines, then HeI 6678 should also show it, which it doesn?t. But is there nebular H-alpha emission around the star that did not get subtracted out this time? Did any of your previous spectra show this? It might be a phase-dependent thing (.e.g. due to colliding winds), so please keep on it! Or it might be a one-shot sort of flare, or even the start of a longer-term event. We won?t know until we compare the whole time evolution of lots of spectra. I wonder what Chandra and MOST are seeing? (We won?t know that for a bit...)

It would be great to get simultaneous data for H-beta, which should also show a central narrow emission peak, although much weaker than H-alpha.

Thanks again for showing this!

Cheers, Tony


From: Keith Graham (fg-spek-convento@vds-astro.de)
Sent: Saturday, December 22, 2012 4:17 PM
To: fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)
Subject: [fg-spek] Re: Request for observations of the 2mag star delta Orionis




I got this del ori profile last night. Looks like it might becoming active.

_________________
Tony Moffat

Hi Tony,

I am quite certain it is del ori. My goto scope is dead on target, and the software that took it there showed del ori on the monitor. I did eps ori immediately after del ori, and the scope moved the correct amount to esp ori from del ori.

BUT, there is always that chance, so I will be on it again tonight if those high clouds clear out. I am anxious to see how tonight's profile compares with last night's. Hopefully some others got a profile from last night to help verify this.

Cheers,

Keith Graham

Hi Again, Tony,

I just noticed something else that is weird. The He1 line has shifted to 6684 whereas the Ha line is still at 6863. I have absolutely no idea what this means, but it may be a clue as to what is going on (or my spectrum acquisition is completely out of whack!!). Is it possible for one line to shift so much while the other stays put? That seems awfully strange to me.

As I said, I will be anxious to see the spectra from others and to obtain another one tonight.

Cheers,

Keith

Hi Again, Tony,

A big WHOOPS on my part, but not completely. I was comparing last night's spectrum with one I took on Dec. 13. Both spectra had the Ha line at 6563, but it was the Dec. 13 spectrum that had the He line at 6684, not the one from last night with the emission line. Still, I am confused as to how one line HeI could shift whereas the Ha did not. And shifting 5A really sounds like something is very wrong somewhere.

Cheers,

Keith

Hi all,

I can't see double peak structure on two observation made
the Dec. 22.838 and Dec. 22.962 (but I have not observation for the
date of 22.0 because cloudy night).

See below my time evolution plot version. Tony, the rapid shift change between
20.8 and 22.8 (for example) can be caused by orbital motion (5.7 d) ?

Christian Buil

Hi Christian:

Very nice spectra! Yes, the shifts appear to be due to orbital motion. All stellar lines go together while the IS lines remain fixed. We hope to be able
to pick out the much weaker lines of the 5.7d companion, moving in anti-phase with the primary. This will take some careful work, though. And maybe we?ll
also pick up the 3rd star. At this point, I can only say please continue to get as many spectra as possible, especially now well into the MOST and Chandra runs.

Best regards,

Tony

From: Christian Buil (fg-spek-convento@vds-astro.de)
Sent: Saturday, December 22, 2012 9:04 PM
To: fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)
Subject: [fg-spek] Re: Request for observations of the 2mag star delta Orionis




Hi all,

I can't see double peak structure on two observation made
the Dec. 22.838 and Dec. 22.962 (but I have not observation for the
date of 22.0 because cloudy night).

See below my time evolution plot version. Tony, the rapid shift change between
20.8 and 22.8 (for example) can be caused by orbital motion (5.7 d) ?

Christian Buil

_________________
Tony Moffat

HeI is normally at 6678A, while H-alpha is at 6562A, both when not shifted. So I?m not sure what you?re saying here. But note that all (or at least most; there
could be exceptions if the stellar temperatures are different...) the stellar lines should move together, while the (mostly narrow except some DIB) interstellar
lines do not shift at all.

Anyway, don?t worry. We?ll figure it all out, especially if we have redundant observations from others.

Best, Tony

From: Keith Graham (fg-spek-convento@vds-astro.de)
Sent: Saturday, December 22, 2012 7:35 PM
To: fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)
Subject: [fg-spek] Re: Request for observations of the 2mag star delta Orionis




Hi Again, Tony,

I just noticed something else that is weird. The He1 line has shifted to 6684 whereas the Ha line is still at 6863. I have absolutely no idea what this means, but it may be a clue as to what is going on (or my spectrum acquisition is completely out of whack!!). Is it possible for one line to shift so much while the other stays put? That seems awfully strange to me.

As I said, I will be anxious to see the spectra from others and to obtain another one tonight.

Cheers,

Keith

_________________
Tony Moffat

OK, but can you show us these spectra, so we can check on it ourselves?

Thanks, Tony

From: Keith Graham (fg-spek-convento@vds-astro.de)
Sent: Saturday, December 22, 2012 7:45 PM
To: fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)
Subject: [fg-spek] Re: Request for observations of the 2mag star delta Orionis




Hi Again, Tony,

A big WHOOPS on my part, but not completely. I was comparing last night's spectrum with one I took on Dec. 13. Both spectra had the Ha line at 6563, but it was the Dec. 13 spectrum that had the He line at 6684, not the one from last night with the emission line. Still, I am confused as to how one line HeI could shift whereas the Ha did not. And shifting 5A really sounds like something is very wrong somewhere.

Cheers,

Keith

_________________
Tony Moffat

The closest spectra I have to that taken by Keith is half a day earlier (not surprising as I'm the other side of the planet) and I don't see any sign of a double Ha line.

Cheers,
Bernard

_________________
Quicquid Nitet Notandum

Thanks, Bernard. But I think we should not necessarily conclude that there never was a double profile. It could have been a short-lived flare.
All the more reason to have as intense coverage as possible, even following Mintaka through the night on as many nights as possible at least
until Jan 7 and at as many different sites as possible. This will help for various reasons, but especially if the H-alpha central emission
(probably better than calling it a double profile) turns out to be real and comes back again. If any line goes into emission from extended hot-gas
(in addition to its normal photospheric broad absorption), then it is indeed H-alpha.

Best, Tony

From: Bernard Heathcote (fg-spek-convento@vds-astro.de)
Sent: Sunday, December 23, 2012 12:36 AM
To: fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)
Subject: [fg-spek] Re: Request for observations of the 2mag star delta Orionis




The closest spectra I have to that taken by Keith is half a day earlier (not surprising as I'm the other side of the planet) and I don't see any sign of a double Ha line.

Cheers,
Bernard



Quicquid Nitet Notandum

_________________
Tony Moffat

I took a spectrum of del ori last night and the emission line was no longer there.

two spectra frm 121211 and 121219

best

berthold

Very nice spectra, Berthold! Congratulations. I wonder what the sharpish core of H-alphs is on one of the spectra ....

Tschuess, Tony


From: Berthold Stober (fg-spek-convento@vds-astro.de)
Sent: Sunday, December 23, 2012 3:59 PM
To: fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)
Subject: [fg-spek] Re: Request for observations of the 2mag star delta Orionis




two spectra frm 121211 and 121219

best

berthold

_________________
Tony Moffat

OK, fine, Keith. Does this mean there was an instrumental problem before or was the central emission reversal real? The latter would be quite exciting,
the former less so...

Best, Tony

From: Keith Graham (fg-spek-convento@vds-astro.de)
Sent: Sunday, December 23, 2012 3:20 PM
To: fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)
Subject: [fg-spek] Re: Request for observations of the 2mag star delta Orionis




I took a spectrum of del ori last night and the emission line was no longer there.

_________________
Tony Moffat

Hi Tony,

I am not aware of any instrumental issue with my equipment. I guess the only way we will know for sure whether or not this thing was real is if there are any other spectra close to the time mine was taken.

Cheers,

Keith

Well then, this looks quite hopeful for a real burst in H-alpha emission! Very exciting, and as I said before, it shows that we need intense coverage
to see how often and where in the orbit of the stars this H-alpha emission occurs. Chandra and MOST should probably have seen a hiccup at the time.

Best, Tony

From: Keith Graham (fg-spek-convento@vds-astro.de)
Sent: Sunday, December 23, 2012 6:30 PM
To: fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)
Subject: [fg-spek] Re: Request for observations of the 2mag star delta Orionis




Hi Tony,

I am not aware of any instrumental issue with my equipment. I guess the only way we will know for sure whether or not this thing was real is if there are any other spectra close to the time mine was taken.

Cheers,

Keith

_________________
Tony Moffat

Hi Tony,

You asked to see my spectra. I have four that I sent to Noel today.

Cheers,

Keith

Hi Tony, Keith,

Plotting Keith's spectra with the possible Ha emission versus mine from earlier that day, after aligning/removing tellurics and continuum removal, I have to say his spectra looks pretty real. It will certainly be interesting to see if any of us can catch this emission again.

Unfortunately my summer weather is very hot (nights >30C) and unsettled so I've not had much luck with clear nights ... but I remain otimistic I can still contribute.

Cheers, Bernard

_________________
Quicquid Nitet Notandum

Hello Tony,


I do Not understand exactly, what do you mean with "sharpish core", but I think, you mean the pink one?


This are parts from two echellespectra. Do you have them or where should I put down them? Would it be enough to adnex them here in the forum?


Cordialement
Berthold

Von meinem iPad gesendet

Am 23.12.2012 um 23:01 schrieb Tony Moffat <fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)>:

Now you see two spectra from 121219 und 121211 near the Na lines


best

berthold

Hi Keith,
In these circumstances I would look carefully at the original images. Most artifacts are much easier to distinguish from spectral features in the image. It could also be a sky line which has not subtracted correctly. The Philips Cosmowhite lamp for example has feature at H alpha but again this should be clear from the original images.

Cheers
Robin

hello,

couild this be correct?

best
berthold

Hi Berthold,

If you are questioning your 96 km/s RV reading then you will see in my 12 December message I reported a 90 km/s shift between two successive nights.

Cheers, Bernard

_________________
Quicquid Nitet Notandum

Hi,i've just finished to reduce several hours of monitoring of del ori using bet eri as telluric star and for continuum restitution, without any emission inside the core of the Balmer series. No changes in HeI lines too.
Keith spectra is very interesting, check your 2D images for light pollution effect/cosmic, we have 2 weeks to find another events.
Cheers
Thierry

2012/12/24 Bernard Heathcote <fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)>

_________________
Thierry Garrel
Observatoire de Fontcaude, Montpellier, France
SpectroBlog http://gabalou.canalblog.com/

Yes, that makes everything look more convincing. While in Keith?s spectrum, the emission reversal in H-alpha is nearly central, in yours it is
on the red edge of the line. So it looks as if a relatively weak (and variable?) but significant emission component may be traversing the H-alpha line
with time (phase?).

But of course Robin is right: everyone needs to check for any extraneous features (e.g. a night-sky line) across the whole spectrum, that was not subtracted out. The best way to do this is by inspecting (and if not visible by eye, making line or column plots) in the 2D image before extraction to 1D.

Cheers, Tony

From: Bernard Heathcote (fg-spek-convento@vds-astro.de)
Sent: Sunday, December 23, 2012 11:47 PM
To: fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)
Subject: [fg-spek] Re: Request for observations of the 2mag star delta Orionis




Hi Tony, Keith,

Plotting Keith's spectra with the possible Ha emission versus mine from earlier that day, after aligning/removing tellurics and continuum removal, I have to say his spectra looks pretty real. It will certainly be interesting to see if any of us can catch this emission again.

Unfortunately my summer weather is very hot (nights >30C) and unsettled so I've not had much luck with clear nights ... but I remain otimistic I can still contribute.

Cheers, Bernard



Quicquid Nitet Notandum

_________________
Tony Moffat

Yes, the pink one, and only in H-alpha 6562, not HeI 6678. The core looks sharper than usual in that spectrum, almost like the reverse of what Keith is
seeing. Noel Richardson is coordinating all the spectra, so please send them to him (richardson@astro.umontreal.ca (richardson@astro.umontreal.ca)). I think he wants all the reduced spectra, but also a sample of a complete set of images leading up to one spectrum.

Gruesse, Tony


From: Berthold Stober (fg-spek-convento@vds-astro.de)
Sent: Monday, December 24, 2012 2:31 AM
To: fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)
Subject: [fg-spek] Re: Request for observations of the 2mag star delta Orionis




Hello Tony,


I do Not understand exactly, what do you mean with "sharpish core", but I think, you mean the pink one?


This are parts from two echellespectra. Do you have them or where should I put down them? Would it be enough to adnex them here in the forum?


Cordialement
Berthold

Von meinem iPad gesendet

Am 23.12.2012 um 23:01 schrieb Tony Moffat )vds-astro.de (fg-spek-convento(==>)vds-astro.de ([email]fg-spek-convento(==>)vds-astro.de[/email]))>:


: Very nice spectra, Berthold! Congratulations. I wonder what the sharpish core of H-alphs is on one of the spectra ....

Tschuess, Tony


From: Berthold Stober (fg-spek-convento(==>)vds-astro.de ([email]fg-spek-convento(==>)vds-astro.de[/email]))
Sent: Sunday, December 23, 2012 3:59 PM
To: fg-spek-convento(==>)vds-astro.de ([email]fg-spek-convento(==>)vds-astro.de[/email]) (fg-spek-convento(==>)vds-astro.de ([email]fg-spek-convento(==>)vds-astro.de[/email]))
Subject: [fg-spek] Re: Request for observations of the 2mag star delta Orionis




two spectra frm 121211 and 121219

best

berthold



Tony Moffat

_________________
Tony Moffat

Hello Bernard ,

Thank you very much for the hint! Later I shall look for the RV using other lines of the spectra.

Best regards
Berthold

Just to let everyone know, we've received the first of 4 Chandra observations, obsid 14567, and the data look great. I've attached a quicklook plot of the Si line region, showing weak Ly-alpha emission from H-like silicon (Si XIV) and the (strong) f-i-r triplet from He-like silicon (Si XIII)

The schedule is

• 14567 (current window 2012-12-19 18:57:26.199 UTC to 2012-12-21 04:24:06.199 UTC)
  14569 (current window 2012-12-22 06:19:44.872 UTC to 2012-12-23 15:52:14.872 UTC)
  14570 (current window 2012-12-24 13:33:45.134 UTC to 2012-12-26 00:17:05.134 UTC)
  14568 (current window 2012-12-27 04:16:15.357 UTC to 2012-12-28 14:34:35.357 UTC)

clear skies,

Mike

Hi Everyone,

I find the discussion and comments over my spectrum extremely interesting and exciting. Being a science guy, I am certainly concerned as to the validity of this spectrum. It is important to know if this is real or if something in the acquisition/reduction process has caused the “bump”. Your comments have driven me to check deeper into anything that might have caused this bump to appear. So far I have run each of the individual images through the ISIS process to see if only 1 or 2 of the 4 images show the feature. It does appear in all four individual images. I then used Maxim to flat field and dark subtract the individual 2D images. I blew up the area around the Ha line to check for hot pixels and cosmic ray hits. None there. In fact, the Ha line looked pretty darn good with brightening at the spot where it shows on the spectrum.

That said, I have been doing spectroscopy for only 2 years. I am no expert and may have missed something. The important thing is to get this right. If someone with more experience than I who knows what to look for would like to examine my images, I can forward them to you for your perusal. If it is a fluke, I can live with that. If it is valid, that would be fantastic. But we do need to know one way or the other, and I will do what I need to do to find out.

Cheers,

Keith

Hello,

You could provide your spectra in this forum, so everybody can reduce it. What do you mean about this. ?

Cheers berthold

Keith, I can try to analyse your original data.

Send data in a zip file to:

christian.buil_at_wanadoo.fr

If possible attach the 4 delta Ori orginal 2D frame + reference frames
(and wavelength reference frame if possible).

Precise you setup, spectrograph and camera (pixel size).

The volume is perhaps large ? You have an ftp solution ?

Send me also you processed spectrum before telluric removal operation

Christian Buil