ISIS b-v values

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Robin Leadbeater
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Joined: Mon Sep 26, 2011 4:41 pm
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ISIS b-v values

Post by Robin Leadbeater »

During reduction, ISIS generates b and v values for each exposure but I cannot find any information on what they are or what they are used for
iis_b-v_values.png
iis_b-v_values.png (5.83 KiB) Viewed 3388 times
Are they the mean intensity in the standard photometric b, v passbands?

Thanks
Robin
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
Robin Leadbeater
Posts: 1926
Joined: Mon Sep 26, 2011 4:41 pm
Contact:

Re: ISIS b-v values

Post by Robin Leadbeater »

Anyone ?
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
Joan Guarro Flo
Posts: 611
Joined: Thu Nov 03, 2011 8:50 pm

Re: ISIS b-v values

Post by Joan Guarro Flo »

Hi Robin,
You're not alone
Yes, what and I'm, but I don't understand and I don't know the answer.

Friendly, Joan.
Christian Buil
Posts: 1431
Joined: Mon Sep 26, 2011 6:59 pm
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Re: ISIS b-v values

Post by Christian Buil »

Robin,

(b) - (v) information is indicative of the impact of atmospheric chromatism (or telescope chromatism) on the spectrophometric quality of the collected data in a sequence of spectra.

This situation is explained for many examples on the web page (in French sorry):

http://www.astrosurf.com/buil/dispersion/atmo.htm

(some time dramatic !)

It is an arbitrary parameter that allows to reject some very affected spectra. This is the case of spectra whose index (b) and (v) (relative intensities) deviate much from the average or median value of a sequence.

Christian B
Robin Leadbeater
Posts: 1926
Joined: Mon Sep 26, 2011 4:41 pm
Contact:

Re: ISIS b-v values

Post by Robin Leadbeater »

Thank you Christian,

This could be useful now for V392 Per which is very low. There are some big variations in the continuum of the published spectra.

Cheers
Robin
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
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