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Values not in the table can be calculated by using linear interpolation. Slum is stellar luminosity, it is the Lum column on the table.
BC is bolometric correction, it is the Bolo. Steff is effective temperature, it is the Teeff column on the table. These will be used in the equations below.
This is important, since generally the only way a planet has oxygen in its atmosphere is by the action of native plant life.
This means that the primary star needs a lifetime longer than 3. This disqualifies stars with a spectral class of higher than F2. Obviously even though K0 stars has a lifespan of 1.
It is of type F7, which means it is hotter and whiter than Sol. Its mass is 1: The diameter is little greater, but spots, prominences, corona, and output of charged particles solar wind are fewer. It is a younger star than ours, though by less than a billion years. Either because of this, or because of variations in galactic distribution, the proportion of heavy elements in it and its planets is somewhat more than for the Solar System.
In earlier days, science fiction customarily put planets around the familiar ones like Sirius, Vega, Antares, or Mira. It was then legitimate enough, if a trifle repetitious.
But today we know, or believe we know, that few of the naked-eye stars will serve. Mostly they are giants, visible to us only because they are so brilliant that we can pick them out across immense gulfs of space.
Sol would no longer be discernible without instruments at a distance of about 55 light-years. Now the red giants like Antares, the variables like Mira, are dying stars, well on their way to the dim, ultra-dense white-dwarf condition.
If ever they had planets—their mass makes that unlikely, as we will see in a minute—the inner attendants have been seared or even consumed, as these suns expanded. Probably the majority of stars in the universe are still enjoying health.
Their temperatures and luminosities vary enormously. The most important reason for this is the difference in their masses. The more massive a sun is, the more intensely compressed it becomes at its core, and thus the more fierce and rapid are the thermonuclear reactions which cause it to shine.
This dependence of output on mass is a highly sensitive one, so that the latter covers a much smaller range than the former. These stars form a well-defined series, from the largest and brightest to the smallest and dimmest, which is called the main sequence. That last, G0, was formerly the classification of our own sun; but more recent information has gotten Sol to be labeled G2.
Figure 1 shows a large part of the main sequence. It omits the extremes, because they really are too extreme to diagram very well.Corbett carefully details the sordid back story of today's "oiligarchy." While most people are well-acquainted with the Rockefeller name, few probably know the true history of .
If a spacecraft is flying far away from anything else, and only has weak rockets fueled by puny chemical fuels or innocuous solar panels, nobody cares if the ship is a hunk-of-junk suffering from decades of deferred maintenance.
There is a grand tradition of scientifically minded science fiction authors creating not just the characters in their novels but also the brass tacks scientific details of the planets they reside on.
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