How many secret stars are there and where are they located.?

There are Fifteen Secret Stars.

You can obtain three Secret Stars by obtaining the Eight Red Coins in the three Bowser Levels.

You can get one Secret Star by sliding down the slide in Peach's Room. You can obtain another one if you slide down within 20.9 seconds.

You can obtain three Secret Stars from various Toads.

You can obtain a Secret Star in the Red Cap Switch Level, Blue Cap Switch Level, and Green Cap Switch Level.

You can get two Secret Stars by catching the Rabiit in the Basement twice.

You can obtain a Secret Star in the secret swimming course by obtaining the Eight Red Coins.

You can obtain a Secret Star in the secret flying course by obtaining the Eight Red Coins.

Hope this helps!

There are 19 secret stars in Super Mario 64 DS. I know that because I got over 120 stars and then I used the cheat code, All 120 course stars, and when I looked I saw that there were 19 of them.
The code for All 120 course stars is
020960f4 ffffffff
020960f8 ffffffff
020960fc ffffffff
12096100 0000ffff
22096102 000000ff

I found 22 secret stars

There Are 130 or 131 Stars With Secret Stars

23

There is 151 stars in the game. But how[ MANY secret STARS ARE THERE!!!!!!!!!!!!!!!!!