Une Be faible (pour moi) et une question

[Gerard Arlic]

Bonjour,
Samedi soir, j'étais seul au T60 du Pic avec l'Alpy 600 et mon Atik383
d'après la météo j'avais deux..trois heures
j'ai choisi sur Arasbeam la Be [KW97] 26-56 mag 11.5
4*900s en bin 2 + étoile de référence HD 39970
j'ai juste eu le temps de faire 2 poses sur cette dernière pour la réponse instrumentale
le profil Pickles A0I colle assez bien avec HD39970

la réponse appliquée sur [KW97] 26-56 me donne un profil beaucoup plus haut que le seul présent dans BESS, celui de Pierre Dubreuil en 2015

je suppose que cet écart n'est pas normal?

[Robin Leadbeater]

Hi Gerard,

The MILES star HD39970 is significantly reddened by interstellar extinction so does not look like the standard Pickles spectrum. See the attached MILES library spectra (Dark blue is the observed spectrum, uncorrected. Light blue is how the spectrum would look without interstellar extinction.) Did you use the uncorrected MILES spectrum or the Pickles spectrum to calculate the instrument response?

Cheers
Robin

[Gerard Arlic]

Hi Robin
so I de-reded the profile of the base Miles with the coefficient 0.82
I recorded it in "mybase", and used the result for the instrumental answer
the profile of the Be is a little different

thank you for these valuable indications
question: can we do the same with pickles?
have a good day

[Robin Leadbeater]

Hi Gerard,

You should not deredden the MILES spectrum in ISIS. The MILES spectra in ISIS are the original spectra as measured (including interstellar reddening) These are the correct spectra to use to calculate the instrument response.

If you use your calculated instrument response with your measurement of the MILES star it should match the MILES spectrum in ISIS exactly (not the standard Pickles spectrum.)

You could try reddening the Pickles spectrum but this will only be approximately correct as the exact effect of reddening is unknown and the actual MILES star might no be exactly like the Pickles standard.

Cheers
Robin

[Gerard Arlic]

OK Robin
with Pickles redden

I'm trying now with Miles

[Gerard Arlic]

yessss!! acec la réponse calculée sur le Miles

ça avance