[vsnet-chat 3483] Re: re 2MASS data format ... also broad to narrow passband transformations

[no name <crawl@zoom.co.uk>]

Brian Skiff wrote:

>      It could be that once the Sloan-Gunn system stuff standardized, the
> bandwagon could shift by its sheer bulk so that the traditional UBVRIJHKLMN...
> colors will fall by the wayside, and we'll be forced to shift to the Gunn
> system.

this is what I reckon'll happen...

...and subsequently everybody will end up making gungie observations!
[gunn g].


...broader passbands for red stars is a step backwards.  I surmise it's
cos light collection's [ie number of photons] easier that way. That's
probably why Wing's useful  modified 3 band system has never caught on,
though I've seen some nice IBVSs based on its use.

...the danger of molecular band enhancement emulating brightness dips
due to pulsation etc is an ever greater one the broader the bands.

...and from what Arne said, people are going to have to stop thinking to
two decimals for magnitudes, or at least start quoting an error with
every mag if they do, and maybe the CCD people ought to use as _many_
comparison stars as possible, not just one with a possible check star as
per the old photometric days. It should be easier to do/automate on CCD
frames, and is akin to what is done in astrometry, where as many stars
as possible are usually used as reference.

...and what happened to Mr Thaun???


John

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