My first spectrum of Epsilon Aurigae

PTS

Hi,
Here is my first spectrum of Epsilon Aurigae.

Telescope : 0.5 m RC telescope
Site : Hokoon
Spectrograph: LHIRES 3 (resolution~17000)
Camera: Canon 300D (modified)
Software : IRIS 5.57 ans VisualSpec
Exposure : 120-180 s (4 images stacked)

The emission at the blue and red wings of H-alpha are clearly visible.

willis

Hi PTS!
    Can u explain a little bit more?  Is x-axis the wavelength in amstron? Is the y-sxis the light intensity per unit wavelength? What is the implication of the reversed spike at around 6568? What informations this spectrum tells us? I would like to know more.
Many thanks!
Willis

PTS

Hi Willis,
Yes, the x-axis is wavelength in Angstrom unit, and y-axis is intensity, which is not calibrated.

This star exhibits emission feature in h-alpha, in addition to the usual absorption.  The explanation is complicated, as I am still reading the relevant literature on this topic. However, the emission parts (that is the emission on the 2 wings of the H-alpha absorption line) may show asymmetry.  The blue wing (to the left of my plot)now looks higher than the red wing.  This may change when eclipse starts later this year.  Thus, the spectral lines may show changes as this binary system goes into eclipse phases.

I am starting to monitor this changes, and I am proposing to IYA2009 and HKAS to start this as a science project.  We are planning to get as many observers as possible to monitor the brightness changes of this star for 2 years (2009-2011).

By the way, I've just recieved my QHY8 CCD camera.  I hope this will allow better control of the focusing and image capture on my spectrograph.

PTS

Raymond_Tse

Dear PTS,

Is it the current QHY or the newer QHY8Pro version ?
What kind of front filter (IR Cut or AR clear glass) ?

Raymond Tse

PTS

Raymond,
It is the QHY8, colour ccd (APS-C size).  It comes with UV-IR filter but it transmits H-alpha at 90%.  I need this mainly for spectroscopy.

PTS

willis

原帖由 PTS 於 2009-2-19 08:54 發表
Hi Willis,
Yes, the x-axis is wavelength in Angstrom unit, and y-axis is intensity, which is not calibrated.

This star exhibits emission feature in h-alpha, in addition to the usual absorption.  The  ...

Thanks for telling! It is interesting , but don't know how the eclipse affect the spectrum... What I know is that usually spectrum tells us about the speed, temp & the content of the star...

[ 本帖最後由 willis 於 2009-2-19 14:05 編輯 ]

PTS

Willis,
This is why we need to make more observations of this star. Observations made in the past century could not give a satisfactory answer.
We only know this is a binary system, with a giant F0 type star (the bright one, with a mass of about 10 solar mass) being eclipsed by another star of unknown nature.  This second "star" probably is enclosed in a circular disc of nebula some 2000 AU in diameter (so it will eclipse the F0 star for 2 years!).
You are right.  The asymmetrical feature of the emission wings of the H-alpha line may be due to Doppler effect, but we are sure.
Like to join me in this study?


PTS

willis

原帖由 PTS 於 2009-2-19 16:02 發表
Willis,
This is why we need to make more observations of this star. Observations made in the past century could not give a satisfactory answer.
We only know this is a binary system, with a giant F0 ty ...

Dear PTS,
    Thanks for ur invitation!  I am a novice in astronomy, although I've learnt a bit about spectroscopy in textbook for more than 10 yrs ago . Are u working in Ho Koon? If that's the case, I might meet u next month in the workshop.
Regards,
Willis

PTS

Willis,
So I guess you are a teacher,  and joining the Teachers' Workshop.
I am not working at Hokoon, but I have been helping them since they planned to build the astronomical facility.
I have been helping with the Teachers' Workshop aslo.  See you then.


PTS

willis

Dear PTS,
The workshop's entries list is not published yet! So I am still waiting. If I know the result, I will let u know.
Regards,
Willis