That is strange. How much does your instrument response vary? I do not think the instrument response changes much between observations at this wavelength and over this short range. How do the spectra compare if you reduce them without instrument response correction ?
Cheers
Robin
Hi, Robin,
mistery solved (I think so). Thanks to the advice of Joan Guarro, I could reduce all the spectra taking a spectrum of October as a pattern and correcting the instrumental response comparing all the spectra with this pattern. Here are the results:
wr140_ 20161201_748_FPC amp.png (69.27 KiB) Viewed 7292 times
For this I only focused on the region of 5630-5760 A for the dates 18-25Dec16:
The is definitely a change in the region just right of the C3 line, between
5690 & 5740 A after 20-Dec-16.
James Foster
Los Angeles, Ca
James Foster
eShel2-Zwo ASI6200MM Pro
Lhires III (2400/1800/600 ln/mm Grat) Spectroscope
LISA IR/Visual Spectroscope (IR Configured)
Alpy 200/600 with Guide/Calibration modules and Photometric slit
Star Analyzer 200
I attach a New Year animation I made in the carbon III emission region, from spectra obtained with my Alpy 600. I wanted to get more spectra in the approach to periastron but weather and opportunity conspired against me. However I think increased emission is clearly visible on 30th November, blue-shifting once periastron is past. I processed the spectra in RSpec but was not confident in obtaining a consistent rectification. So I used the average intensity between 5600-5630 Angstroms as the anchor point for each spectrum. If the weather improves here in Southwest England then I will obtain more spectra to complete the animation
Cheers
Hugh
WR140 7th July-28th Dec 2016.gif (44.44 KiB) Viewed 7268 times
Evolution of WR 140 since the beginning of december.
The graph clearly shows the change of the spectral profile before and after the 18th of December (periastron date)
Nice spectra Oliver & Robin!
I finished WR140, or I should say, my house finished it by obscuration!
I'm doing pretty pictures btw storms in Los Angeles, but will soon set the
spectrograph to continue Pleione observations and some CaK/Hy spectra of
solar analogs.
James Foster
Los Angeles, CA
James Foster
eShel2-Zwo ASI6200MM Pro
Lhires III (2400/1800/600 ln/mm Grat) Spectroscope
LISA IR/Visual Spectroscope (IR Configured)
Alpy 200/600 with Guide/Calibration modules and Photometric slit
Star Analyzer 200
Here is may last spectra plotted along with my results at periastron and early Nov.
Robin - this is a very similar to your last plot but I find that post periastron the CIII line is shifted to the red. I am correcting for HRV and the Na lines line up nicely.
Did you align the CIII line in your plot? I am worried that something funny may be going on with my dispersion calculation (although everything looks sensible).
v1687cyg_ 20161105_015_tlester.png (34.98 KiB) Viewed 7137 times
Weather permitting I may be able to get one more spectra before WR140 disappears behind trees.
Yes the spectra are approximately shifted to the WR velocity frame of reference. Sorry I should have stated that in the post. The RV of the two components is changing fast around periastron.
If you are contributing spectra for this pro-am campaign, Noel Richardson and Tony Moffat would like to have them by the end of the month. You can send them to.