tas August 8, 2017 at 12:29

Galaxy Generation and Teaching Basic Astronomy

Introduction

Some time ago, at home, I decided to see what’s new about space in recent times. My 7 year old son found me in this matter, showing great interest in this topic. While I was racking my brains about how simple and intelligible, and also in what volume, to give the child information about space, I came across an article saying that it was decided to return the subject “Astronomy” to Russian schools in the 2017-2018 academic year, but only from grade 11. This was the event that prompted me to write this article to help familiarize children with the basics of astronomy before grade 11.

In fact, a 7-year-old child is a representative of a certain sample of users who are either interested in astronomy now, or will be interested in it in the future. It is for them, as well as for those who will give knowledge about the stars, I suggest trying the method below. The main idea is the generation of the Galaxy using real data (I will take this part on myself), and the subsequent use of the result of generation either in games or as a teaching tool for those who would like to make studying astronomy more interesting ...

Theory

The main and most complete information describing the stars are currently:

The main (Harvard) spectral classification of stars.
Yerkes Classification Based on Luminosity (IWC).
The Hertzsprung – Russell diagram (see figure below).

The Hertzsprung – Russell diagram The

Harvard classification defines the abscissa of the Hertzsprung – Russell diagram, and the Yerksky diagram determines the position of the star in this diagram.

The main information that can be drawn from these sources is that all the stars are divided into classes according to their color, that they are of different sizes and that the class and size depend on each other. In order not to get confused in size, you can additionally introduce to everyone a clear gradation of size from 1 (any dwarfs) to 5 (any giants), where sizes from 2 to 4 go to the stars of the main sequence.

Now a rather large amount of information can be reduced to a very simple system “Class, Color, MIN size, MAX size”:

O, Blue, 2, 4
B, Blue White, 1, 4
A, White, 1, 4
F, Yellow White, 1, 5
G, Yellow, 1, 5
K, Orange, 1, 5
M, Red, 2, 5

Now that we know what stars are, it remains to take into account some of the most common or just interesting features of stars:

A supernova is a star ending its evolution in a catastrophic explosive process. The flash can be several orders of magnitude larger than in the case of a new star. Such a powerful explosion is a consequence of the processes occurring in the star at the last stage of evolution.
A binary star is two gravitationally bound stars orbiting a common center of mass. Sometimes there are systems of three or more stars, in this general case the system is called a multiple star. In cases where such a stellar system is not too far removed from the Earth, individual stars can be distinguished through a telescope. If the distance is significant, then we can understand that in front of astronomers a double star succeeds only by indirect signs - brightness fluctuations caused by periodic eclipses of one star by another and some other.
Pulsars are cosmic sources of electromagnetic radiation coming to Earth in the form of periodic bursts (pulses). According to the dominant astrophysical model, pulsars are rotating neutron stars with a magnetic field that is inclined to the axis of rotation. When the Earth enters the cone formed by this radiation, it is possible to fix the radiation pulse, repeated at intervals equal to the period of revolution of the star. Some neutron stars make up to 600 revolutions per second.
Black holes are among the strangest and most attractive objects in outer space. They are extremely dense formations, the force of attraction of which is so great that even light is not able to avoid these hugs. When a star uses its last fuel, the process of dying begins. In luminaries of smaller sizes (about one third of the mass of the Sun), the new core is gaining the shape of a neutron star or white dwarf. But, when a big star dies, it collapses inside itself, thus creating a starry black hole.

Generation requirements

Now, armed with theory, you can estimate what you really want and what general requirements should be taken into account when generating:

The size of the Galaxy in terms of the number of stars should vary from less than a hundred to several thousand.
The sizes, spectral classes and features of stars should be taken from modern classifications.
For the names of stars, the names of really existing stars and constellations should be used. Moreover, it is desirable that, in addition to the name, its class, size and feature coincide with reality.
For star names outside the constellations, names must be generated as a number.
The galaxy must have nebulae.

In the best way, knowledge is remembered during the game, for this you need to add a little to the Galaxy that is in almost all modern space-themed games.
Let's imagine that there is some hypothetical game “Deep Deep Space” in which all the stars in the Galaxy are connected by star paths to each other, where there is a Wormhole and many other interesting things. Then the following requirements will be added to the above requirements:

The galaxy should be flat, with a uniform distribution of stars across all areas, or filling only a certain area specified by the template.
All possible types of stars should be present on a map of any size (without taking into account the real percentage ratio between the classes)
All stars of the Galaxy must be connected by starry paths to each other.
The number of paths for a star should be from 1 to 5.
The paths between the stars should not cross each other or cross other stars.
There must be several Wormhole in the Galaxy that can cross stellar paths, but cannot cross each other or cross other stars.
The colors of the stellar paths and the Wormhole should be different.

It remains to add requirements for the result:

The generation result should be presented in the form of a map of the Galaxy in graphical form (or in another format that can be simply visualized) for visual control and selection for future use.
On a map in graphical form, sizes, spectral classes and features of stars should be clearly visible and uniquely identified.
The map in graphic form should have a designation (legend) for all sizes, spectral classes and features of the stars that can occur on the map.
It should be possible to correct and view the map in graphical form without the use of proprietary software on any computer configuration that they put in schools and at home.
The result of the generation should be presented in XML for further use by developers.

Generation

I will not focus on this point, after all, the article is not about that. I can only say that after some thought, I came to the conclusion that the generation of the Galaxy consists of the following steps:

Nebula layer generation.
Setting stars in groups of 3x3 sectors, in each of which one star is added for each class and several black holes - only 65 stars. This fulfills the requirement of uniformity.
Installation of constellations in which the stars are assigned the names and attributes of real stars.
Setting features in a certain number of stars that do not belong to the constellations.
Adding Star Trek and wormholes.
Formation of the result in graphical form.
Formation of the result in XML format.

As a result, we get just such a random map for a 1x1 size:

Card sizes can be any from 1x1 (65 stars) to 10x10 (6500 stars).

Using the result in practical exercises

When the master Yoda in the famous film said: “And may the Force be with you!”, Perhaps he had in mind, among other things, the power of the SVG format. This is a text vector format that is supported by all modern browsers. The map above is almost entirely drawn in it (except for nebulae and the background).

The idea of using the result is that in the classroom the child himself draws a sector of the Galaxy or a constellation. To do this, you will need:

A computer.
Blank SVG text file with a blank galaxy map.
Card with the coordinates and attributes of the stars (or another task option)

Next, participants insert stars from the card at the coordinates that are described in the card or simply within their sector. An example of a description of one star is given below:

Here, the 1st line displays the name of the star, the 2nd - the ring around the star, simulating radiation and the third - the star itself. Thus, you need to change the coordinates of the objects, for "circle" set the radii and the number "fill: url", which corresponds to the class. If necessary, the stars are connected by lines. An example of a line description is given below:

All the charm is that the result can be viewed immediately on any computer. It’s a good idea to give your child the opportunity to add an extra star by calling her his own name and deciding where it will be located, as well as what size and class it will be. In the end, the one who leads the lesson easily with a simple copy-past can combine the sectors drawn by the group into one map. Or, a ready-made result will be immediately obtained if one participant draws one constellation, for example, of any zodiac sign (see figure below).

The result of such classes will be that the children will receive solid basic knowledge on the classification of stars, will be able to navigate perfectly in the constellations and will never confuse the White-blue “Rigel” with the red “Betelgeuse”, shocking adults with unexpectedly deep knowledge of the constellations, stars and their features. That's all - original ideas and interesting activities for you!

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