Re: Return to No Stealth in Space

In article <47dfed4e$0$24120$4c368faf@[EMAIL PROTECTED]
>,
Ben Crowell  <crowell07@[EMAIL PROTECTED]
> wrote:
>James Nicoll wrote:
>> 
>> 	Let's say that the largest rockets are about the size
>> of an oil tanker. A quick back of the envelope calculation
>> suggests that a 500,000 tonne ****p with a mass ratio of 4 and
>> an acceration of 1 G [1] and an exhaust velocity of 5000 km/s
>> might have a peak power output of 5^16 Watts (plus whatever 
>> for ineffeciencies).
>> 
>> 	Could we spot this at 4.3 LY? Would we recognize it
>> for what it was?
>
>Cranking similar numbers from your scenario, I get 10^36 photons/s,
>and 10^3 photons/s in a 1 m2 telescope. The problem is that you've
>got a star there as well.

	Three stars, actually. That probably doesn't help (Even a
trip to AC 3 spends most the time it's actively accelerating within
about 10 AU of the origin and destination stars).

>
>This is all assuming visible light. If the thing emits copious
>radio or gammas or something, then I think it's a whole different
>ballgame.

	What's the naive calculation of the temperature of a 5000 km/s jet?
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