Forums / The Science / Spectroscopy / 16 July 2009 eShel Spectrum of epsilon Aurigae
16 July 2009 eShel Spectrum of epsilon Aurigae
First contact is fast approaching. This may be one of the last spectra taken before the eclipse starts. The attached file is a low resolution spectrum of the visible region of epsillon Aurigae taken by Olivier Thizy (France) on 16 July 2009. Note the large hydrogen alpha and sodium D lines. In particular, the sodium D absorption lines are extremely strong. The spectrum was taken with an eShel spectrograph and C-11.
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Hi Nikki, The software program VSpec allows you to easily compare spectra. You can subtract two, divide or just display two together. There have been a lot of spectra taken of epsilon Aurigae this past year so once the eclipse is underway I am sure you will be seeing lots of comparisons. The trick will be to determine was is caused by the eclipse. This is because, out-of-eclipse epsilon Aurigae shows a lot of spectral activity.
Hi Nikki, Ihave currently started doingexactly that with the neutral Potassium line at 7699A to determine the contribution from the eclipsing object which is already visible at this wavelength. http://www.threehillsobservatory.co.uk/astro/spectra_40.htm It should be possible to identify the contribution and also watch the red and blue shift due to velocitychanges throughout the eclipseas we see first theedge of the rotating object which is moving away from us and then in the second half of the eclipse, theedge which is moving towards us. Robin
Hi! Would it be possible to make differential spectra: S(PE)- S(E)?Where S(PE) in spectrum pre-eclipse and S(E) spectra in middle of eclipse. Sodium lines are also measure for interstellar reddening E(B-V), it would be nice to make EW od D line- E(B-V) of Eps Aur.