Forum der Vereinigung der Sternfreunde

Hello Lothar,

you make a very important statement! Not only the flats, calibration and spectra images show defects, but also the darks and possibly the bias.
However the analysis should be refined. Shifts of a few pixels do not show up in the statistics, but they disturb the preprocessing of images, adding additional noise to the preprocessed images by using an incorrect dark and bias. If you look at the difference of the darks to an average dark more defects show up. So I subtracted the darks from an average composed of the "good" images and looked at the noise pattern. From these images I sorted out further images and took a second iteration with average from the rest.
This can be repeated until all dark differences show only read out noise with an rms of around 20 ADU. I put a detailed summary of the procedure, done with ISIS as attachment for the curious reader.

I am not going to repeat my earlier remarks on the camera and good experimental practice.

Regards, Martin

Hello Martin,

your statements are right, the simply statistical test I made is not sufficient to detect all kinds of read out failures in darks or bias or ThAr images.

But yesterday I had some time to do some exercises in Midas and so I took the darks of 20130609 purely by chance and found this defects.

_________________
Herzliche Grüße / best regards

Lothar

https://lotharschanne.wordpress.com/

Hi,

the declination engine has still a problem. We can't reach the HD-Stars. We do not expect reparation before thursday (fr. open door, weekend, service nights).

Team 3

Hello Gerrit, Hello Berthold,

I analyzed some of your last spectra, from June 19 and uploaded them on the server under ..\20130619\20130619_ISIS_spectra.zip. They look very good! You may use the downtime at the telescope to do the spectra reduction yourself with ISIS to process the rest of the spectra. For a quick start you can load the configuration in the ZIP file into ISIS (see my quick guide and detailed instructions on the ISIS website, where you can also download the program):
http://www.astrosurf.com/buil/isis/isis_en.htm
A good tip: sort out the bad images first!
For Berthold: I also include my calibration files in the ZIP folder, it contains all the information for sucessful data reduction and a cleaned dark image as discussed recently. You also need it together with my configuration files.
Here just an example of the processed spectra.

Regards, Martin

Hi Martin!

Thank you for your excellent work and help!

Best regards
Berthold

Hi,

The IAC-80 isn't observing!

The declination engine isn't working again.
We do not expect observations before thursday (weekend, service nights).

Team 3

Hi all,

IMPORTANT information for Teide observers:

Please try to get a RV standard (delta Sgr or bet Aqr) EVERY night. The ThAr wavelength solution is having some difficulty converging in a nice way, and these observations have become critical. Both stars are very bright, and won't take much time. Thanks!

Also, please remember that we can fix the readout errors at Montreal for the science and flat frames. As long as the readout errors aren't too many (<~10% of the frames), they won't matter for bias and dark frames at all. However, if there is a readout error on a ThAr, please redo that frame immediately, these are nearly impossible to fix unless we happen to be very luck in where the lines are placed. So, the only readout problems we are concerned with at the telescope are the ThAr.

Below is a screenshot of WR 134 from 20120525 where we had a readout error. It is fine, even compared to another that didn't (both overplotted on same scale - note that our problems with a wavelength solution make this more difficult, but this is the H-alpha/He II 6560 region).

Thanks,

Noel

Thank you, Noel! That gives us the final confidence that the read-out problems can be properly managed. I already told the teams that ThAr images should always be repeated in case of such trouble. Costs us only a minute.

Cheers, Thomas

Hello,

for security reasons it could be better to take 2 or 3 ThAr images as a series in each case?

_________________
Herzliche Grüße / best regards

Lothar

https://lotharschanne.wordpress.com/

Hi Noel,

Does that nightly RV standard requirement apply when only HD160529 and HD316285 are being imaged, which is my situation?

Cheers, Bernard


From: Noel Richardson (fg-spek-convento@vds-astro.de)
Sent: Thursday, June 27, 2013 4:55 AM
To: fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)
Subject: [fg-spek] Re: Teide 2013 WR campaign




Hi all,

IMPORTANT information for Teide observers:

Please try to get a RV standard (delta Sgr or bet Aqr) EVERY night. The ThAr wavelength solution is having some difficulty converging in a nice way, and these observations have become critical. Both stars are very bright, and won't take much time. Thanks!

Also, please remember that we can fix the readout errors at Montreal for the science and flat frames. As long as the readout errors aren't too many (<~10% of the frames), they won't matter for bias and dark frames at all. However, if there is a readout error on a ThAr, please redo that frame immediately, these are nearly impossible to fix unless we happen to be very luck in where the lines are placed. So, the only readout problems we are concerned with at the telescope are the ThAr.

Below is a screenshot of WR 134 from 20120525 where we had a readout error. It is fine, even compared to another that didn't (both overplotted on same scale - note that our problems with a wavelength solution make this more difficult, but this is the H-alpha/He II 6560 region).

Thanks,

Noel






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_________________
Quicquid Nitet Notandum

Lothar -

It's probably a good idea to default to two ThAr lamps each time.

Bernard -

Let me look at the data tomorrow, could you get one of them next time just to play it safe? Thanks!

Noel

Hi Noel,

Probably overkill, but I have been taking three ThAr spectra every before and after each target spectra.

I have imaged the supplementary MOST LBV targets on seven occasions but, so far, only done one RV (del Sgr), on 19 June ... do I need more frequent RVs?

I see you are trying to drum up AAVSO member participation in the WR campaign. While I am confident that will help with finding photometrists I doubt it will bring more spectroscopists on board ... but worth a try.

Cheers, Bernard



From: Noel Richardson (fg-spek-convento@vds-astro.de)
Sent: Thursday, June 27, 2013 12:09 PM
To: fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)
Subject: [fg-spek] Re: Teide 2013 WR campaign




Lothar -

It's probably a good idea to default to two ThAr lamps each time.

Bernard -

Let me look at the data tomorrow, could you get one of them next time just to play it safe? Thanks!

Noel





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_________________
Quicquid Nitet Notandum

Hi Bernard,

Get another one to make sure everything is stable. Based on my previous use of your data (delta Ori), I'm sure it's fine, but better to be safe than sorry.

I asked for the AAVSO notice well before the campaign started. With delta Ori, it helped get a few professionals on board when they were observing, and might have brought one amateur spectroscopist on board. The photometry will be a good addition too, though.

Cheers,

Noel

Hello team 3

what about the news of the telescope status and the possibilities of observations ? The telescope can not be repaired?

_________________
Herzliche Grüße / best regards

Lothar

https://lotharschanne.wordpress.com/

If the read-out problems would be the only trouble...

I just got a message from Alex Oscoz that the telescope has a "coupling problem" introduced by the service observations. No observations this night again... part of the motor is working bad and hence it breaks the couplings.

Details later.

Thomas

After a skype talk with team 3 I know more. The clutch between the dec motor and its worm is damaged and the telescope can't move in dec. Very sad, especially because this problem is not new and it remains unclear if it has been properly or preliminary fixed last week. I simply don't know. The technical team is working hard to fix it. In any case, this night would have been lost, anyway, because of the Calima wind from the Sahara bringing plenty of sand...

Cheers, Thomas

I wonder if they could get the dec motor fixed to a certain dec position, and then we just follow a WR star all night (couldn't do tellurics, RV stds, or other things, but we could get some science done...) as we wouldn't have to move except in RA then.

They probably wouldn't like that option though.

Yes, probably...

We were pointing the MONS by hand in the previous campaign.. how does the idea sound in IAC800? Are there declination setting circles, and the possibility to lock and unlock the axis?
No dia 27 de Jun de 2013 20:28, "Thomas Eversberg" <fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)> escreveu:

_________________
Fil.

Hi Filipe

This telescope has no mechanical setting circles. So far I have seen, there is no possibility to move the telescope by hand.

I am rather astonished about these mechanical defekts of this telescope and the obviously big problems to solve them......

Cheers
Berthold

Hi all! On Filipe's idea (thank you Fil) I just sent an email to the STELLA people asking if they can take over with their echelle in case we are in trouble. Waiting for an answer...

Thomas

Great news: We get four additional nights from IAC!

Alex Oscoz kindly donated the six nights July 21, 22, 23, 24, August 19, September 6. In return we give back the two nights July 10 and 11. This helps compensating our lost nights due to technical problems. This is highly generous and we all should appreciate that by performing well and in good collaboration.

The updated schedule can be found at: http://www.iac.es/telescopes/media/cale ... html#13may

Cheers, Thomas

Again great news: This Monday our colleague olivier Schnurr at AIP Potsdam will meet the STELLA people (1.2m at Teide). He has good hope that he will get the nights during service at IAC80. In case of lasting technical problems they might even jump in next week.

Cheers, Thomas

Hi Noel,



Given that HD316285 is classified as a Be star do you have any objection to me uploading my echelle spectra (processed, not raw spectra) to the BeSS archive (http://basebe.obspm.fr/basebe/MenuIntro.php)?

At the present time BeSS have no spectra for this star and one of my long running tasks, when not otherwise occupied, is to reduce the large number of southern Be stars without any data in the database.



Cheers, Bernard

_________________
Quicquid Nitet Notandum

Hi,

yesterday G. Grutzeck sent me some testspectra of my eShel . I see a great (!) deviation of the ThAr spektrum of nearly 30 (!!!) pixels in both direction (x and y) . This is very much. So much I have never seen, when I used the eShel all over the time I had it in my hands. This also cannot be explained by a simply connecting or disconnecting the fibers and even not by moving with care the hole eShel...I suspect, thats anything much more massive must happened.........but surely I cannot say what's happened. So it is not quite easy for me to adapt now ISIS or midas software all two weeks.....but clearly , I have not to do so.........


cheers
berthold

Bonjour Berthold,you're right. It surely came from plugged and unplugged the object optical fiber. I  never touch this part. It's a good idea to make some fix 30cm radius buckles on a plan with adhesive tape near the entry of the spectroscope to make it more stable during telescope movement and to never unpluggled the entry of the eshel.


Cheers
Thierry



2013/6/29 Berthold Stober <fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)>

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

Hello Team 3 (or 4)

in case of taking images of ThAr or Flatlamps: Is the pinhole (fiber) exactly in the center of the illuminated disk on the mirror you see in the image of the ALCCD5 ?

_________________
Herzliche Grüße / best regards

Lothar

https://lotharschanne.wordpress.com/

Hi,

we had some technicians in the dome at the beging of the week.
The fiber isn't in the middle of the illuminated part (see Image).

Team 4

PS.: How I can upload a fits file (more than 2MB)?

Hi Gerrit,

The positioning of your calibration fibre with respect to the hole is not perfectly central but it is fine ... better than mine:)

Bernard

_________________
Quicquid Nitet Notandum

Hi team 4! Leave it as it is. Seems fine.

Just for information to everyone: We can't avoid unplugging the fibers because of service nights. We reduced the number of service nights by changing tw nights plus generously getting 4 more nights from the IAC. Anyway, if there is a glitch in the 50 micron object fiber this glitch also occurs in the ThAr. Hence, no problem.

Cheers, Thomas

Hi,

there my spectra of WR135....i am not very happy with this result. I think there is some trouble with my CCD Fischer 1603. I'll discuss this with Lothar.....nevertheless, I 'll demonstrate my result fo the last night. over this, I have to try to improve the result of reduction

cheers
berthold

Hi WR gang! Good news from the Teide front!

Olivier Schnurr from AIP in Potsdam just sent me the following information. For the last six service nights where IAC80 is not operating the people from AIP STELLA generously offered to take one spectrum per night of all our three prime targets. They will take two 15min spectra each plus flats and biases (darks not necessary, they say). S/N around Halpha ~130 with R=55,000 (binning will increase S/N). If IAC80 is down again, they might jump in.

Great colleagues, indeed, and many thanks to Ollie for his efforts!

Something else as a reminder: Thanks Grant Hill our two nights at KECK telescope will be on July 25 (NIRSPEC) and on August 11 (ESI). NIRSPEC is a NIR echelle and ESI is an optical echellette.

PLEASE TRY TO GET SPECTRA DURING THESE NIGHTS IN ANY CASE!

Cheers, Thomas

Hello new IAC80 team,

good work!
The shift of the spectra by about 30 pixel in X- and Y-direction required some adjustments in the settings of ISIS for the reduction. These changes in the spectra are much larger than what is usually observed after unplugging and plugging the fibers into the spectrograph. The connection of the fiber with the spectrograph is made with an FC connector, which gives quite a good repositioning of the fiber within a few micrometers. Of course it is a good idea to remove the fibers at the telescope side during service and when not in use, to avoid pulling on the fiber inadvertently. The data reduction works quite well as the examples below show. The single orders were defined over the same ranges as before to simplify comparison. The fit files, configuration and calibration files can be found on the server under 20130629ISIS_spectra.zip. As always, the spectra are not corrected for atmospheric absorption. The spectrum of zet Aql has been used for reference. Keep observing this reference star!

Regards, Martin

Hi all! I just skyped with team 4. IAC80 is operating again.

Cheers, Thomas

Fine work Martin!!

I realized that my WR135 spectrum has a mistake in calibration, here you find the corrected calibration. I tried to do it with isis, because it is easier to delete warm pixels with this software,but I have problems with calibrating using ISIS. one have to use an ASCII file with the lines , the dispersion and the degree of equation......but this is not running in my hnads without error anouncing.....

cheers
berthold

Hi,

The IAC-80 isn't observing!

The declination engine isn't working again.

Team 4

Gosh! I contacted Alex again. No answer yet. Seems they have lasting trouble with the motor and/clutch.

Thomas

Hi again! The technicial team is working on it. They spend extra hours beside their working time. I think this is simply bad luck and we should appreciate their efforts.

Thomas

hello,

I am observing WR135 and WR137 , at time we have clear skies.......should I upload the files on the server in montreal? I cannot reach completely the asked quality .......

cheers
berthold

Hello Berthold,these spectra looks good, but the astrophysical requirement is half an hour exposure maximum per observation to see details moving on the profiles. You may divide your own in three different individual observations as you total exposure in 10X600s. It make a good and valuable series for both star.


Cheers
thierry



2013/7/10 Berthold Stober <fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)>

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

Hello Thierry,


Thank you.......I am afraid, if I would use only three spectra with 600sec.....the S/N would be very low!. I 'll try it this evening again. It could be, that I have improved the slit position of my lhires .....what do you mean, please?


Cheers
Berthold

Herzlicher Gruss Berthold

Am 11.07.2013 um 19:12 schrieb thierry Garrel <fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)>:

The requirements we posted are for a S/N of 200 per A in an hour, not a half hour. We chose a half hour for Teide because we met our needs that way, easily. For additional data, an hour is fine, and if we don't quite meet a S/N of 200, we would still like to try and use the data.

For example, say we can get a S/N of 100 in the continuum of WR 137 in an hour. The CIV 5696 line reaches a little more than 4x the continuum, so the blob and/or wind structure features at the top of the line would have a S/N of 100*sqrt(4) = 200, which is probably going to be a good addition to the campaign. If you do more sub-exposures, we may divide them up into two actual spectra for the night, or we may use them to create one good spectrum. The time coverage added with amateur astronomers observing everywhere will make a large contribution to the campaign.

We hopefully start a run at the Observatoire du Mont-Megantic tonight in Quebec. We had last night (fog) through the 28th of the month, except for two nights. Let's hope for clear skies for both Megantic and Teide!

Cheers,

Noel

Hello Gerrit,

you have had sent me some "testspectra". Excuse me,but they look to me rather strange. I avoid to say rather "bad"........

The flux of the LED flat has only 4500!!! and this with an exposure time of 22". I cannot comment this and do not understand this at all.

The same I observe with the tungsten flat, there I only see a flux of maximal about 7000...much to less for the target stars.....the exposuretime here is 7 sec.!

And the ThAr spectrum is shifted about 5 pixels, not to explain by simply put on and away the fibers.......and alo has only a flux of about a half of the earlier ThAr spectra. This week spectra tell me, anything must be wrong with the spectrograph.......

but this change is not so problematicly as the weeknes of all calibration files.......I estimate, you will get rather week targest spectra also....

But unfortunatly , I can't help you.........ask perhaps Lothar Schanne or the other experts of this compaign.

cheers
berthold

Hello new team on Teide,

welcome. I hope you will feel well on the IAC and will have success in your measurements.

Yesterday evening the test spectra sent by Gerrit (LEDflat, Tungstenflat) had very pour signal level. About 1/7 of the normal expected values. On the other hand the images has been well focused (FWHM of the orders about 4 pix). This is suspicious and we need to find the cause for that behaviour ! What causes the dramatic light loss ?

Please, can you load up the measured data of last night on the Montreal server ? Then we can prove the data and help to find the reason of the problem.

_________________
Herzliche Grüße / best regards

Lothar

https://lotharschanne.wordpress.com/

Hi all! The problem is solved. Daniel Verilhac checked it out and found that the connector at the guiding box was not properly adapted. He is alone at the telescope for the next three nights but he will manage.

Cheers, Thomas

Hi all! With some astonishment I got a message from IAC that they uninstalled our guiding unit for the neighbored TCS telescope. The TCS needs fovia during some days and it has "higher priority". Now we have to hand guide the telescope. I am not told when the unit is back.

Thomas

excellent conditions here so I should be able to get a full set tonight

Robin


----- Original Message ----- From: Thomas Eversberg (fg-spek-convento@vds-astro.de)
To: fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)
Sent: Monday, July 15, 2013 8:36 PM
Subject: [fg-spek] Re: Teide 2013 WR campaign



Hi all! With some astonishment I got a message from IAC that they uninstalled our guiding unit for the neighbored TCS telescope. The TCS needs fovia during some days and it has "higher priority". Now we have to hand guide the telescope. I am not told when the unit is back.

Thomas

Hi friends:

Here are my fresh results of WR134 last night.

Instrument Response is made by Altair at 5411A.

Happy to recieve your comments.

Dong

Hello Dong,

Are you sure you are at the right wavelength? Here are my results from 20130712 and 20130715 for comparison

Cheers
Robin

----- Original Message ----- From: Dong Li (fg-spek-convento@vds-astro.de)
To: fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)
Sent: Wednesday, July 17, 2013 6:36 AM
Subject: [fg-spek] Re: Teide 2013 WR campaign



Hi friends:

Here are my fresh results of WR134 last night.

Instrument Response is made by Altair at 5411A.

Happy to recieve your comments.

Dong