General Offer of Expertise

[BlackChakram]

Hi everyone. I've got a degree in astrophysics that I rarely get to use. That being said, if anyone is working on a map with realistic elements and could use some spot expertise (where to place gas giants around stars, how common black holes are, etc etc), I'm more than happy to offer my services.

I'm hoping this is an acceptable place to post this. If not, my apologies. Just wanting to be helpful. I'll gladly relocate or remove the thread if necessary!

[Naima]

Hello and welcome ... This thread might interest you ...

http://www.cartographersguild.com/ge...s-realism.html

[BlackChakram]

Ah thank you. I figured there was a thread like this somewhere. Just couldn't find it.

If there's a thread for larger scale things, I can tackle those, too!

[Domino44]

I have said this before and I am going to say it again, I love star maps. I have done a few, but mine have been less realistic and more aesthetic. The next time I have a hankering to design a star map I hope that you will be able to give me some pointers! I did study astronomy but it was more about the myths and legends concerning differing constellations, stars, clusters...etc. So my knowledge of the actual science regarding stars is a bit limited. Thanks for offering your insight!

[BlackChakram]

My pleasure! One of the things I love most about astronomy is that truth is way stranger than fiction!

[sozme]

I would definitely love to get your help...

I'm in the outlining stages of a work of fiction (really, a series of works), and I'm stuck on the finer details of where in the galaxy I should put my alien worlds. I'm really looking to have this level of detail down in an image file before I really start writing: http://fc03.deviantart.net/fs70/i/20...rt-d5u3tvb.png (just as an example of what I'm going for). I

I have the names and a lot of the details of the characters, plot, etc. (I've been working on outlining this story for years now). Now I'm to the part I've been avoiding so far - the actual science and actual mapping of the galaxy I'm creating and the individual worlds in which the story will take place. I already have names for pretty much everything.

What I really wish I had was a template to start with, but I cannot find any that I think are suitable mainly because if I place a homeworld in some place, I begin to wonder what the actual constellation is called, what the star is (if it actually has a name i.e. 85 Pegasi), whether it's an appropriate location or absolutely preposterous. Basically I envision my story coming with a map of the detail I've given as an example above, but I don't want amateur cosmologists seeing it and saying to themselves, "Wow, that seems completely ridiculous."

I am a physiologist by training, so I have a great deal of the alien stuff already imagined in well enough detail to not sound like a complete idiot, but the only physics I took was in my undergraduate pre-med classes.

[BlackChakram]

Alright. Galactic structure and formation was my specialty, so we can go as deep into this rabbit hole as you would like. First, this image is your best friend.
Milky Way Annotated

We can't take a real picture of the galaxy because we're stuck inside it, but this artist's rendering for NASA is about the closest you'll get.

So let's start with the basics. Galaxies are ridiculously freaking huge and ridiculously empty. If everything out to Pluto were shrunk down to only 25 mm across, the nearest star would be a similarly sized circle 2 soccer fields away. So some form of FTL travel is a must (my personal favorites are the folding and expanding of space around the ship, and the jump-bubble concept from Traveller).

Anyways. One of the biggest things that will raise hackles from astronomers is to say something like "they've jumped 6 light years. That puts them in the heart of enemy territory!" 6 light years would be like... 2 stars away. At best. If you want an empire that controls, say 50 star systems, you're talking about a sphere maybe 20 light years across. And that's if they own every star within that area and there are no empty areas. Supernovae create bubbles of voids where no stars form. These are usually a few hundred light years across.

As for start types, we're learning that more and more stars could have habitable planets. 75% of the stars in the galaxy are small, red, type "M" stars. These are relatively cool and put out more infrared than visible light. Planets with life could form around them, but they'd have to be close to the star - like closer than Venus. So on a world like this, you'd have a big red sun in the sky and life that likely sees in IR. Stars like the sun only make up about 10% of the total. The really big ones - Class "O" and "B" are rare, making up only about 0.1% of all stars. These ones emit so much x-ray and gamma radiation that even being on a planet really far out won't save you. Additionally, half of all stars are in either a binary, trinary, or higher (mutiple) star system. There are severa l layouts with things like this that work.

Black holes are also somewhat rare. The closest one to earth is 3,500 light years away. However, the density depends on distance from the core. As for habitability in the galaxy, the Mass Effect map you linked pretty much has it down. I swear, Bioware must have had an astropysicist on staff because their science is clean. The closer you get to the center of the galaxy, the older and denser the stars you encounter. Near the core, most of the stars are what we call Population II, an older generation of stars with less metals (read: any element beyond helium). Since they have less metals, these stars rarely have planets. Even if they did, the extra density of stars closer to the center would create too much radiation for life to survive. So on that map, the hole they left in the center area is remarkably realistic. The stars out in the arms of the galaxy have younger, more metal-rich stars and more activity. This is where you get nebulae, the large stars, and lots of planets.

As for names and constellations, you don't need to worry. If you take a look at the NASA map I linked, something like 90% of all named stars and constellations are within that smallest circle - maybe 500 light years across.

The fantastic map I've linked below is the only one I've ever seen that shows the region only a few thousand light years out. It should give you an awesome sense of how void bubbles, nebulae, and other features are laid out.
Galaxy Map 2.0

Whew. That's all I can think of for the basics. I will happily elaborate on any of these points if needed. Hope this helps!

[sozme]

Thanks for your reply and the great map you posted. The main issue I am having, not only with this individual mapping project but with writing in general is that I have a fairly severe clinical OCD. It is extremely difficult for me to actually place some of the homeworlds on a galaxy map because I am unsure about whether or not that specific spot is reasonable, whether or not that specific spot has a star system in it that is actually named, and whether or not there is some other identifying marker there that I could use in creating the map. I've been planning the details of the story itself for many years now, but I'm stuck on this one part. I might just have to try to pay and hire someone like yourself to help me actually create the map. Ive tried to do it so many times myself but have been completely unsatisfied and have not been able to find a good resource to make it easier for me.

[Azélor]

Thanks for your reply and the great map you posted. The main issue I am having, not only with this individual mapping project but with writing in general is that I have a fairly severe clinical OCD. It is extremely difficult for me to actually place some of the homeworlds on a galaxy map because I am unsure about whether or not that specific spot is reasonable, whether or not that specific spot has a star system in it that is actually named, and whether or not there is some other identifying marker there that I could use in creating the map. I've been planning the details of the story itself for many years now, but I'm stuck on this one part. I might just have to try to pay and hire someone like yourself to help me actually create the map. Ive tried to do it so many times myself but have been completely unsatisfied and have not been able to find a good resource to make it easier for me.

are you creating a new galaxy or adding stars to the Milky way like in Mass effect?

My best tips in worlbuilding in general if your not sure what to do : imitate your surrounding. Look at where the Sun is in the galaxy. Why ? What's around ?
If I remember correctly, the homeworld in mass effect shared some characteristics. Where are they located in the galaxy and what kind of star they have are probably the 2 most important criteria that I can remember.

BlackChakram: I would like to hear what makes life and/or planet formation less probable. You said that being close to the center of the galaxy makes these impossible or being too close to a nebula. Are there other objects or phenomenons that might prevent the creation of life ?

[Naima]

Soon we should have a whole map of the universe thanks to the Gaia telescope ... Gaia overview / Space Science / Our Activities / ESA