Milky Way Galaxy Model

Make Your Own Milky Way Model

We can see Milky Way, the fuzzy light band in the night sky (if the sky is dark enough), and you might know that Milky Way is the place where many many stars get together.

Do you know what is Milky Way?

Milky Way is a disk galaxy (spiral galaxy) that is made up of approximately 200 billion stars.
The diameter of the disk is 100,000 light years, it means that it takes 100,000 years to across the disk with light. Our Solar System is located at about 30,000 light years (28,000 light years) away from the Galactic Center. We live in the disk and we watch the disk from the inside.
Let's make your own Milky Way models to feel Our Galaxy familiar to you.

1) Milky Way Disk Model

You can download "How to Make a Milky Way Galaxy Model" in PDF file.

PDF file in English (204KB)

PDF file in Japanese (288KB)

The data of the model is based on:

"The spiral structure of our Galaxy determined from H II regions", Georgelin, Y. M. & Georgelin, Y. P., A&A (Astronomy & Astrophysics), 49, 57 (1976) for nebulae at star forming regions (HII regions)
" Mass, luminosity, and line width relations of Galactic molecular clouds", Solomon, P. M., Rivolo, A. R., Barrett, J., & Yahil, A., ApJ (Astrophysical Journal), 319, 730 (1987) for molecular clouds (GMCs) at Galactic longitude = 8 - 90 (deg)

2) Milky Way Panoramic Model

With the disk model

You can download "How to Make a Panoramic Model of the Milky Way Galaxy" in PDF file.

PDF file in English (924KB)

PDF file in Japanese (1004KB)

You can also download panoramic charts of the Milky Way Galaxy in PDF file.
All three (3) charts are necessary for the panoramic model.

Chart 1: Galactic Longitude = 60 - 180 (degree)

PDF file in English (140KB)

PDF file in Japanese (204KB)

Chart 2: Galactic Longitude = 300 (-60) - 60 (degree)

PDF file in English (136KB)

PDF file in Japanese (184KB)

Chart 3: Galactic Longitude = 180 - 300 (-60) (degree)

PDF file in English (104KB)

PDF file in Japanese (160KB)

The data of the model is based on:

" A composite CO survey of the entire Milky Way", Dame, T. M., Ungerechts, H., Cohen, R. S., de Geus, E. J., Grenier, I. A., May, J., Murphy, D. C., Nyman, L.-A., & Thaddeus, P., ApJ (Astrophysical Journal), 322, 706 (1987) for distribution of molecular (CO) gas

Photos of making the disk model (Math/Science Conference 2005)

Photos of making the panoramic model (MKAEC Open House 2004)

Hands-on Workshops for Miky Way models

3) Milky Way in the Night Sky

Now you know that we live in the Galactic disk and we watch the disk from the inside. That is what the Milky Way is in the night sky. So which part of the disk do we see in the night sky?

Each spiral arm has a name at its tangential direction (except Perseus arm, becuase it does not have a tangential point).

A: Scutum arm, B: Sagittarius arm, C: Perseus arm, (in the northern sky)
D: Carina arm, E: Crux arm, F: Norma arm (in the southern sky)

Direction:
(1) Toward the Galactic Center: l = 0°
(2) Toward the tangential point of the Scutum arm (A): l = 33°
(3) Toward the tangential point of the Sagittarius arm (B): l = 50°
(4) Toward the Cygnus X region: l ~ 81°
(5) Toward star forming regions (IC 1795, 1805, and 1848)
in the Perseus arm: l ~ 135°
(6) Towad the anticenter: l = 180°
(7) Toward the Gum Nebula, a supernova remnant: l ~ 264°
(8) Toward the tangential point of the Carina arm (D): l = 283°
(9) Toward the tangential point of the Crux arm (E): l = 305°
(10) Toward the tangential point of the Norma arm (F): l = 327°

l : Galactic Longitute

Which part of the Milky Way disk do we see at night?
See for yourself using the following sky chart:

See Milky Way in the summer constellations (July 1, 8pm in Hilo, Hawaii)

See Milky Way in the autumn constellations (October 1, 8pm in Hilo, Hawaii)

See Milky Way in the winter constellations (Mar 1, 8pm in Hilo, Hawaii)

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Last Updated on Aug 03 2006