Tag Archives: Beta Comae Berenices

Creating a Fictional Planet’s Calendar

When humans finally manage to colonise another planet, there will be some significant differences between life on that planet and life on Earth.  One of them is the calendar.  Why would the Earth’s calendar be inadequate?

First, the orbital period of the new planet will be different than Earth’s 365.25 days.  Second, the length of the day is going to be different.  Third, with these two basic pieces of information, the year will start at different seasons, and midnight would happen at different times of day.  It would make no sense.

So, what we need to do is create a new calendar and timekeeping system.  I’m going to use my fictional world of Ariadne as an example.  I have yet to figure out the calendar, so I’m doing it on the fly as I write this post.

First of all, we need to determine the distance of the planet from the star, which is Beta Comae Berenices.  To do this, we need an equation.  We’ll start with the equation that is used to determine the temperature of a planet (and rearranged to solve for distance D).

D = (Ts^2Rs/2Tp^2)((1-a)/(1-τ/2))^1/2

D is the distance to the star, Ts is the temperature of the star, Tp is the temperature of the planet, Rs is the radius of the star, a is the albedo of the planet, and τ is the optical depth of the planet’s atmosphere.  Going through this, I want Tp to be equal to 288 Kelvin, which is similar to Earth’s.  The albedo should also be similar to Earth’s which is 0.39.  And the optical depth should be similar to Earth’s, considering the atmosphere is very similar.  Therefore, that should be 0.6.  The temperature of Beta Comae Berenices is 5,935 Kelvin, which is slightly hotter than the sun.  The star is also slightly larger than the sun, 1.106 times the size, and therefore has a radius of 770,154,252 metres.  Plug all these in the equation, and we get a distance of 152,657,589 km, which is slightly larger than the distance of the Earth from the sun.

Now, to determine the orbital period of the planet, we need the mass of the star, the orbital radius, and the mass of the planet.  We’ll use Kepler’s Third Law for this. To simplify this, I used this very handy tool to calculate the period.  The semimajor axis is set to 152,657,589 km, the mass of the planet is 1.028 Earth masses (as it’s 2.8% more massive than Earth), and the mass of Beta Comae Berenices, which is 1.15 times the mass of the sun.

We have a result of 0.961094 Earth years, or 351.046 days.

Now, as for the calendar, I’m going to be making up some numbers a bit here.  I’ll keep the numbers the same for the planet and star, but the year will be 351.1 days.  This means that the day on Ariadne is slightly shorter than Earth’s day by 13 seconds.  That’s all.  For the clock, a standard 24 hour clock with 60 minutes can continue to be used, though it’ll have to be adjusted a little.

As for the calendar, to get a nice round number of days per month is a bit difficult.  However, based on a 351 day year, a 12 month calendar with 29 day months is possible.  There are an extra 3 days, though.  They could be distributed around to 3 other months, but I’d like to do something special.  At the beginning of each year, there will be a 3 day month.  It’ll be a 3 day period for people to celebrate the colonisation of the world.

Now, to account for that extra 0.1 days, we can add leap years every 10 years.  Add an extra day on the decade to the holiday month, so on every 10th anniversary, there’s an extra long holiday.

As the year is slightly shorter, people’s ages will increase a bit faster.  So, a 50 year old person on Earth would have an age of 52 on Ariadne.  It won’t make a big difference, though.  However, colonists will have to figure out a new birthday based on this new calendar.  That can be calculated by regressing the calendar into negative years to find the birthdate.  The landing date will start with year 1, holiday month day 1.

Another matter is to name the months.  This will come at a later date, as the colonists haven’t arrived at the planet yet!  They’ll have time to name them.

I hope you found this post informative.  This is going to be Ariadne’s standard calendar, and it will be described with names in the future.

Announcing the title of my upcoming duology

I’m happy to announce the title of my upcoming science fiction duology, as well as the name of the planet and the star.

The title is Ariadne: Origins.

It takes place on the planet Ariadne in the Beta Comae Berenices system, a star just under 30 light years from Earth.  The name Ariadne comes from the alternate name of Coma Berenices (Berenice’s hair), Ariadne’s hair.  While no planets have been discovered around this star yet, it is on the list of high priority targets for sun-like stars to host exoplanets.  While it’s only 3 billion years old, that doesn’t mean evolution happens at the same pace as it has on Earth.

I haven’t decided the title of the first book, but I’ll announce it when I’ve finished writing it.  I have no definite timeline for it to be finished, but I hope by summer.  Editing will commence after that.

In the meantime, I will be writing short stories to lead up to the release of the book, and to give you something to read.  I’ll be providing plenty of information about the world to give you some background, although it’s not necessary that you read it to understand the book.

You can read the announcement here.  To receive updates about the books, please subscribe to this blog or my official website.