# How close together are the stars near the center of our galaxy?

1. Short answer, yes! (with some assumptions)

According to these lecture slides, the stellar density near the Galactic center is ~100 stars per cubic parsec (compared to ~1 star per cubic parsec in the stellar neighborhood). This corresponds (assuming I did my math right) to an average distance between stars of 0.13 parsecs (0.42 lightyears). If a star like the Sun were that far away, it would have an apparent magnitude (in V-band) of -4.6 mag. Wikipedia lists -4.0 as the faintest magnitude at which one can see things in the daytime sky with the naked eye. Since -4.6 is brighter than -4.0 (because smaller magnitude means brighter object) you could see a star like the Sun at 0.13 parsecs away (although, probably only if you have good eyesight). If you have stars in the sky that are brighter than the Sun or closer to you than the average distance between stars, then you’ll have a better chance of seeing them.

2. http://i.imgur.com/RibFV9P.gif

http://www.astro.ucla.edu/~ghezgroup/gc/pictures/orbitsMovie.shtml

> A 2.2 micron animation of the stellar orbits in the central 0.5 arcsec. Images taken from the years 1995 through 2013 are used to track specific stars orbiting the proposed black hole at the center of the Galaxy. These orbits, and a simple application of Kepler’s Laws, provide the best evidence yet for a supermassive black hole, which has a mass of 4 million times the mass of the Sun. Especially important is the star S0-2 as it has has been observed for more than one full orbital period, which is only 16.17 years.

3. Because stars are so closely packed together near the galactic center, the night sky for inhabitants there would be spectacular. Near the galactic center, the average distance between neighboring stars would be only 1000 AU (about a light-week). If the Sun were located within a parsec (=3,2 light year) of the galactic center, there would be a million stars in our sky with apparent brightness greater than Sirius. The total starlight in the night sky would be about 200 times greater than the light of the full moon; you could easily read the newspaper at midnight, relying on starlight alone.

Source: http://www.astronomy.ohio-state.edu/~ryden/ast162_7/notes31.html

4. Within a parsec of the galactic center, the estimated number density of stars is about 10 million stars per cubic parsec. The number density of stars here in the Sun’s neighborhood is a only 0.2 star per cubic parsec.

The nearest star to the sun is about 4 light years away. In the galactic center, the average distance between neighboring stars would be only 1000 AU (about a light-week). Not only would the starlight to be bright enough to read by at night, many of those stars would be visible during the day. However, I doubt anyone is looking up into those spectacular skies. Most of the stars are young and hot and will explode as a supernova within a few million years. Between the supernova and any outbursts from the nearby supermassive black hole at the galaxy’s center, most of the planets in the region have been sterilized from the radiation.

http://www.astronomy.ohio-state.edu/~ryden/ast162_7/notes31.html

http://www.space.com/414-death-stars-sterilizing-galactic-center.html

http://en.spaceengine.org/

Its a universe simulator. It has procedural generation of every star in every galaxy so you can visit all of them. (Yes, every star in every galaxy). All types of planets are simulated so you can find one with water and atmosphere go down to the surface.

For what you ask, I would fly to the center of the galaxy and search for a star with a planet system. Then I’d land on the planet on the day side and see what the sky looked like.

http://en.spaceengine.org/_ph/8/114589036.jpg

quick tutorial:

mouse wheel for speed and forward and back arrows to travel

click to lock, “g” to go to the selectged object

“F2” to identify planets around a star

6. The center of this image is the site of Sagittarius A*, a point containing an extremely dense mass widely thought to be the supermassive black hole at the center of the milky way, with stars in very tight orbits. The orbits of a few objects in our solat system is provided for scale.

7. A quick wiki search gives you the following:

> A typical mass density for a globular cluster is 70 MSun pc−3, which is 500 times the mass density near the Sun.

Apparent magnitude, or how bright we see objects here on earth, is on a logarithmic scale. log(500)= +/- 2.7

> Brightest star (except for the Sun) at visible wavelengths: Sirius at -1.47

> Faintest objects observable during the day with naked eye when Sun is high at –4.00

Note that the lower the value, the higher the brightness. E.g. the sun has -26.74. Now I feel like I’m cheating a little bit by equating the mass density to apparent magnitude, but I suspect it is at least a good indicator.

-1.47 -2.7 = -4.17 which is just bright enough to see when the sun is high.

Therefore my answer to this question would be yes, but barely.

*Edit: That said, if you are anywhere near a star like R136a1, you are very likely to see them during the day. It has a luminosity of 8.700.000 times that of the sun.

8. Apparently, stars are packed very close together. 10 million stars per cubic parsec; around our neck of the galaxy, it’s about 0.2 stars per cubic parsec. Source.

A cubic parsec is roughly 3 x 10^49 cubic meters. If we assume the stars are evenly distributed, that’s 3 x 10^42 m^3 for each star. Which would mean that the stars are about 1.5 x 10^14 meters apart from one another. The distance from the earth to the sun is 1.5 x 10^11 meters, so these stars are separated by about 1000 AU. So I’d hypothesize that you probably wouldn’t be able to see other stars during the day. However, the night sky would probably be really really cool looking. You’d have 10 million stars within half a parsec of you (1.6 ly). From earth, the closest star is Proxima Centauri, which is 4.3 ly away.