Samuel Oschin/Schmidt camera & huge field of view (13×13 moons)

1:14:03It was a sky survey that was taken up by the Samuel Austin telescope, which is a camera that is mounted on the Samuel Austin telescope at Valomar Observatory. There you can see the the telescope itself. It's got a Schmick camera and this thing is specialized for wide field photography. These cameras are actually pretty insane because so that camera the camera that is that is attached to it has a field of view of 6.6° by 6.6°. Okay. So 6.6 degrees by 6.6 degrees. The the full moon for comparison is half a degree. It's about like if you were to put your thumb right in front of your face, the the size of

1:14:44your thumb is about half a degree. This is 13 full moons by 13 full moons. So, it's 170 full moons. >> Mhm. >> Big is the field of view of this camera, right? And >> because it's so big, there's a specialized camera called a Schmidt camera. And what it does is you've got you've got a primary mirror, right? The mirror is about 1.2 m. That mirror then goes into the camera. You can imagine the the light is getting warped, right? As the light comes in, it gets warped. And so the edges of your field of view are going to get distorted. >> Yep. Yep. >> This specific camera is specialized for

1:15:26that kind of wide field photography. So it corrects for that distortion. And even then, the focal plane is actually not flat. You know how in like a camera your CCD is basically a flat piece of equipment because all of your light is coming onto a flat piece of equipment here because it's such a large field of view and it's so so big the focal the focal plane is actually curved. So in order to get a photograph your photograph the the the the plate in this case the photographic plate and these are all photographic plates that are used also has to be curved. And so you got to like warp it before you slide it

1:16:07in there and get this photograph. I thought that was really cool. Like the the amount of stuff that needed to happen in the 1950s in order to get these kinds of large field of view photographs right? >> Given the technology of this is purely photographic, which means that the other cool thing is that that that um the the telescope that we just saw that telescope is an equatorial mount. Okay? And what that means is that one of the axes is parallel to the Earth's axis of rotation. And so all you have to do is rotate along that axis and it'll follow the stars as the Earth rotates underneath. Right? The the the stars are all going to move in a circle around the North Star. And so in order to track a

1:16:48single spot in the sky, the telescope has to rotate with the Earth so that it points in one direction in the celestial sphere. And in order to actually do that back then, they had a manual astronomer that would look through a 10-in smaller telescope to a guide star and then and then control the telescope manually to keep that guide star in the exact same position. So there was a lot of like manual stuff going on back in the day. And I think this is really important to see to to understand >> how how the data was collected, right? It's not with this modern technology where now everything is automated and

1:17:29nothing is actually in equatorial because it's it's easy to it's easier to make bulkier telescopes in the azimuthal mount >> where I can control both axes with a computer and I I just have to like do the calculation and control both axes and I'm fine. Right. Um, so this guy survey produced a thousand photographic plates, about a thousand, one in red, one in blue. So then you'd have about