Sometimes I'm a little thick. From a previous topic in this forum it sounds like people have an interested in spectroscopy and LPVs. I'm doing a pilot study with the help of a student, but thanks to weather in central Illinois this spring we haven't got a whole lot of data. So while staring at the underside of clouds tonight it dawned on me that maybe some of the readers in this forum would be interested in contributing data to my student's project.
The idea of the project is simply that Matt Templeton and I have batted around the idea of incorporating crowd-sourced spectroscopy into a larger project to study long period Miras. We are unsure what all of you might be able to observe in long period Miras with the different equipment widely available out there. I figured the best way to get an idea was to try. About that time a student landed in my office looking for a project. Matt gave us a potential target list and we've been working on it for about five months.
I want to emphasize this is a pilot study. It is nothing more than a glorified fishing expedition to see what we can get. The very preliminary results with just a little bit of data has actually been more than I expected. If the results are promising, our ultimate goal is to build a more well considered program for the AAVSO.
To this point, the project has focused exclusively on what can be observed using an SA200 filter-wheel grating. But the larger idea is to figure out what the range of non-professional rigs may be able to contribute so in that spirit we could include spectra from other types of instruments as long as I get the data in a dark corrected format with enough additional information to do a decent wavelength calibration.
If this interests you please email me jmart5 _at_ uis.edu. I'll send you a target list and set up a way for us to share data. We would be happy to have whatever you may be interested in chipping in.
[Note: topic edited from "LBV" to "LPV" - Ed.]
Dear colleagues,
are you talking about LPV`s (long period variables) or about LBV´s (luminous blue variables)?
Best wishes, Ernst Pollmann
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International Working Group ASPA
Active Spectroscopy in Astronomy
http://www.astrospectroscopy.de
http://www.astronomie.de/astronomische-fachgebiete/spektroskopie/
The
Long Period Variables.
The term LBV (Luminous Blue Variable) is so convoluted in meaning in the literature that I avoid using it at all costs.
I might be able to contribute! I'm getting a Spectra L-200 in the next week or so. see: http://www.jtwastronomy.com/products/spectroscopymain.html
What kind of resolution would we need to support this project? I'm getting multiple gratings so I should be able to go from 16 - 1.1 Angstroms/per pixel on my C-11, Classical Cassegrain 13", and/or possibly the CDK17.
I say possibly for the CDK17 (17" @ F6.8) because the highest resolution grating (1800 ln/mm) is made for F/10 speed systems.
James
Hi James,
would you be interested in phototmetric and spectroscopic observation of the LBV star P Cyg?
Best wishes, Ernst Pollmann
----------------------------------------------
International Working Group ASPA
Active Spectroscopy in Astronomy
http://www.astrospectroscopy.de
http://www.astronomie.de/astronomische-fachgebiete/spektroskopie/
To: Ernst,
Sure. I can only do this, however, when it high in the evenning sky. I have a very poor eastern sky and can't stay up like I do for my automated photometry. So soonest to start would be in September until it gets too light to shoot in early evenning, like January. Are you intested in the whole visual spectrum or just certain lines? I should be able to do both with a low (300 ln/mm) and a high (1800 ln/mm) grating.
James
Hi James,
wonderful, that you are willing to contribute to the long-term monitoring project.
If you could take spectra with the 1800 L/mm grating which covers the range from 6520 to 6700 Angstr., and more or less contemporaneous the photometric brightness, this would be a great input.
Are you informed about this project?
Best wishes, Ernst
To: Ernst,
Are you refering to the P Cyg formu at ARAS: http://www.spectro-aras.com/forum/viewforum.php?f=17
If so then I'll check this out when P Cyg gets into position. I might be able to make some early observations if I take my scopes out to the field and do it July or August.
James
yes, I did this.
If
Hi James,
yes, I did this.
If you wants to get more information in detail, you should have a look to "projects" and > there to "P Cyg" at my website. Anyway, it's great that we can expect your first measurements after the summer.
Ernst
At TSP out in Ft. Davis, TX, I tried my hand at a mira near max. C11 with 0.7x reducer, Alphy 600. 8x120s exposures. Alkaid as reference star. ISIS reduction, VSpec image. Resolution = 525. AAVSO-reported V mag on 18 May was 8.8.
Note cursor at Ha (6563 A) which appears to be an emmision line. Also note what appear to be emmission lines in Hbeta and Hgamma (little spikes on left side). If I am wrong about these emmission lines, let me know, I am new at this.
Ed
Hi Ed,
I send you a series of photographic spectra of the prototype of the mira stars omicron Ceti (taken in 1988). Maybe this will help you, to identify some characteristic bands (TiO and C2) in your spectrum.
I have some doubts, that at the curser position should be an emission line.
On the other hand, at the blue region of your spectrum could be Hgamma and Hdelta in emission.
It would be meaningful to calibrate in wavelength your spectrum.
Ernst Pollmann
Hi Ernest:
The spectrum was reduced using the camera response curve generated from the reference star and calibrated ISIS. The cursor line is at Ha (6563 A). The other emmission like spikes are at 4340 A and 4101 A.
Ed
Hi Ed,
I couldn't recognize, that the spectrum was calibrated already.
But you confirms, the both emissions in the blue region are Hgamma at 4340.5 and Hdelta at 4101.7 Angstr.
Nevertheless: Halpha in emission? unlikely.
Ernst
Ernst:
I agree, when magnified there is a tiny dip at the Ha position, I just needed to examine the spectrum in more detail.
Ed