Long-period comets have periods of over 200 years.The longest would probably be somewhere around a million years (comparable to the orbital periods of objects in the Oort cloud); much longer than that, and it will go away far enough to be captured by the gravitational field of other stars.
Short period comets have a period of less than 200 years
Long period comets have a period of more than 200 years.
A comet with a period of 200 years or more.
600,000,000,000,000,000,000,000,000,000
comet shoemaker is aredy gone, it does not have a period.
That depends on what you call 'long' or 'short'. Halley's period is in the neighborhood of 75 years, give or take a few years. Since that's short enough for two perihelions to occur within a single human lifetime, I guess it ought to be considered a short period.
It changes so it will next be seen in 4337
A comet with a period of 200 years or more.
A comet with a period of 200 years or more.
Long period comet
Comet (C/2010 X1 (Elenin)) is a long-period comet.
600,000,000,000,000,000,000,000,000,000
The orbital period of Halley's Comet is about 75.3 years.
each 76 years
comet shoemaker is aredy gone, it does not have a period.
Between 74 and 76 years.
A short period comet.
Halley's comet has a period of 76 years.
Not more than 200 years - less than 200 years. As to the "why", that's because this is how "short-period" vs. "long-period" is defined. Any comet that takes less than 200 years for one revolution is defined as short-period.