Are More Stars Visible in South America than North?

[Judi Lynn]

Are More Stars Visible in South America than North?

July 19, 2015 – 5:00 AM



A friend from South America says more stars are visible from the southern hemisphere than from the northern one. I disagree. Aside from more lights in North America, which I realize may obscure our view from some locations, how can this be possible?

—M. L., Santa Fe, N.M.

More stars are indeed visible with the unaided eye from the southern hemisphere, but not because more stars exist in that direction of the universe. The reason is that the South Pole is oriented toward the center of the Milky Way, our own galaxy. It’s easier to see those relatively nearby stars than stars that are farther away.

http://parade.com/411043/marilynvossavant/are-more-stars-visible-in-south-america-than-north/

(Short article, no more at link.)

[packman]

1. I see the Southern Cross there

quite prominent. I read somewhere that the star field is not as dense below the equator. Earth's orientation, I expect.

[lumberjack_jeff]

3. tangential, I know, but it's interesting how a song can inspire imagination

I'm thinking of course about the CSN song of that name.

[eppur_se_muova]

2. But there are more *bright* stars in the Northern.

The center of the Milky Way is in Scorpio/Sagitarrius, which is below the celestial equator but visible from the NH in the Summer, and nowhere near the South Pole -- sorry, Marilyn. But the perpendicular to the plane of the galaxy -- i.e. where the disk is thinnest -- is in the NH, in the constellation of Ursa Major. This is where the Hubble Deep Field photos were taken, since there are fewer stars and nebulae to block the view of other galaxies. The opposite direction would be the constellation of Toucana (IIRC) but the solar system is closer to the North pole of the Milky Way so there are more stars in the southern direction. This is where the Hubble Deep Field South was taken.

Something like 15 of the 20 brightest stars are in the NH; the 2nd and 3rd are in Carina, which is in the SH. The SH also has the Magellanic Clouds, the Carina Nebula, and other charms, but the brightest constellation is our good old Ursa Major, which contains several bright stars traveling in a group (the brightest star in the sky, Sirius, is also part of that group, but nowhere near Ursa Major from our POV), and the second brightest is Orion, which straddles the Equator.