Alpha Centauri 2

Sid Meier's Alpha Centauri & Alien Crossfire => The Theory of Everything => Topic started by: JarlWolf on July 20, 2013, 08:28:07 AM

Title: Question about Alpha Centauri daylight/night time hours
Post by: JarlWolf on July 20, 2013, 08:28:07 AM

How long are days on Alpha Centauri, and how long is there daylight? Or is there even any night time at all? Because there is 2-3 stars I believe. But me lacking knowledge of their orbits and other things I am not exactly sure of how long days/nights really are, and better yet seasons, or if there even is seasonal changes. I know there is the Hercules Perihelion of course where sunlight increases dramatically but that's more of a climatic thing that lasts for 20 years.

Title: Re: Question about Alpha Centauri daylight/night time hours
Post by: Petek on July 20, 2013, 02:40:56 PM

According to Appendix 5 of the SMAC manual, each day on Planet lasts 17.53 hours. However, the number of hours of daylight isn't specified. That same appendix also states

Quote

With only a slight axial tilt, any seasonal differences are minimal.

Title: Re: Question about Alpha Centauri daylight/night time hours
Post by: Geo on July 20, 2013, 07:18:37 PM

What Petek said. Daylight (from Alpha Centauri A) would be just under 9 hours.
Alpha Centauri B (Hercules) is alot more fickle. During half the year, Hercules would be visible in Planet's "night" sky, so you could think of this time as the "white nights" northern Canada, southern Scandinavia, and northern Russia experiences in the region 500 km below Earth's arctic circle.

Title: Re: Question about Alpha Centauri daylight/night time hours
Post by: JarlWolf on July 20, 2013, 10:54:42 PM

So it's basically there is a rough 9 hour daytime combined with whatever hours of daylight added by a crazy and fickle star.

Hmm.... this can mean two things: Either it can be very bright for long time, or pitch black after the initial daylight hours. Which means temperatures will also probably fluctuate dramatically...

Edit: Thank you. I'll be able to apply this to my AAR.

Title: Re: Question about Alpha Centauri daylight/night time hours
Post by: Geo on July 21, 2013, 01:45:08 AM

Temperature fluctations would be less then Earth experiences. For starters, the shorter night means less time for heat to escape into space. But more importantly, the denser atmosphere has a better capacity to retain heat.

Title: Re: Question about Alpha Centauri daylight/night time hours
Post by: Lord Avalon on July 21, 2013, 02:16:10 AM

Also from Appendix 5, pp. 214-5:



               Sun   Alpha Centauri A  AC B
Mass           1.00       1.08         0.91
Luminosity     1.00       1.45         0.45
Spectral Class  G2         G2           K5
Surface Temp   1.00       1.00         0.73
Diameter       1.00       1.09         0.70

A is yellow, B is orange.