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Re: (meteorobs) More on LM estimates and sources of error in ZHRs
>I recall, from my early biology classes, that the human dark-adapted
>retinal rod cells, are extremely efficient in responding to just a few
>photons to yield a detectable response. If the average rod cells, at
>their limit, respond to a few photons at mag 6.5, how can a rod cell
>respond to 1/9 as many photons (which is the luminosity ratio for the
>8.9-6.5 = 2.4 mag difference here) , because that many photons just are
>not going to be there ?
Mike, I think it would be difficult to argue that the photons are "not there"
based on an a priori assumption that response at 6.5 is "at the limit", wouldn't
it? Anyway, I think as George said, we're no longer discussing human perception
here: what this sounds far more like is, "*I* have excellent night vision, and
*I* have access to excellent dark sites, and *I* have never seen mag 7 stars (or
mag 8, or what have you) - and therefore, it is impossible...
I hope this won't offend ANYONE, but I am quite clear that I am able to see
stars fainter than mag 7.5 under appropriate conditions. If that is something
specific to my vision (or anyone else's), that's OK - so LONG as I accurately
record my conditions, so my meteor (or nova, extragalactic supernova, variable
or whatever) data can be reliably corrected for that individual variation.
That's basically the whole gist of Limiting Magnitude: what can THIS individual
see, and how will that affect their reported observations...
Take care all,
Lew
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