Eps Aur approche de sa conjonction solaire. Elle est chez moi très basse à l'horizon encombré d'une colline. Je suis obligé de lancer les acquisitions quasiment en plein jour, enfin dés qu'elle est visible à l'autoguidage.

Voici donc peut être le dernier spectre avant sa conjonction et le retour du coté du petit matin.


"perhaps the last spectra of eps aur before sun conjunction. Low on the northwest horizon during sunset, i have to begin capture during daylight as soon as it's visible in the autoguider cam"

20mm exposure, R=15700, SNR=34

eps_aur_20100517screenshotha details, blue and red wings had completely disappear as the inside blue rebound seems getting more intense"ew_courbe

Here is a comment from Bob Stencel on the Ew evolution:


I salute your efforts - your measurements of the H-alpha equivalent width have provided the clearest indication of the extent of the approaching central clearing, presumably dominated by excitation effects of the central hot star.  Excellent work by you and others, and we hope you can resume in a few weeks after solar conjunction.
--Dr.Bob Stencel, U of Denver Astronomy"

In the same time, Jeff Hopkins report:

"Observers are reporting a brightening in the V Band. Recent data shows a steep brightening curve with current brightness nearly 3.65. for the latest V Band Composite Plot, see http://www.hposoft.com/Plots09/VBand.JPG "

What a pity to miss the Brightening, an important phase of the central eclipse. I gone fight the hill...


Le brightening semble commencer comme l'indique l'augmentation de la largeur équivalente et la magnitude. Quel dommage de loupé ça !



I have able to uplift my mount and have now 60mn before Aps aur set. So the game is not over, not yet.

Last spectra, very fast changes of the Ha lines, enlarged and intense blue peak inside.


eps_aur_2010052140cm de plus en hauteur et c'est reparti pour 60mn de suivis de plus ! Le spectre change de façon rapide et brutale, une incroyable épopée.