Astrophotography

[Rivendale]

Glad you liked it. I started taking astrophotos when I was a teenager in the 1980s. I use to do piggyback shots with my old Mamiya 55mm camera. It was on top of my scope which was guided by a clock drive that could track but not very good. Then my career hit and I stopped until I retired. The technology has completely revolutionized astrophotography and it took two years to learn how to do it. It is also pricey. My setup cost almost 10,000 bucks and that is a low budget range. Cell phone apps can stack multiple images quiet effectively. Comets don't require long exposures but they take some time processing because the comet is moving different relative to the stars. Galaxies and comets are my favorite and I have photos of over 200 Galaxies and probably 20 to 30 comets.

I think the comets and galaxies would be cool to see if you have a chance to post them in the future. And if you have shots of Andromeda or Hale-Bopp, I’d love to see them.I remember Hale-Bopp in the mid-90s—you could just barely see it with the naked eye around sunset, even in the city.

Today, I love using the Sky Guide app on my iPhone or iPad. It’s so neat—just open the app, point your phone at the sky, and you can see the stars, the zodiac constellations, and a host of other things. It even beeps when the International Space Station flies overhead. It’s $50 a year but free for one week, so it’s a great way to quickly check what you’re looking for.It’s especially nice to open the app early in the morning while it’s still dark. You can point it at the eastern horizon and see the Sun, along with Mercury, Venus, and sometimes the Moon—all lined up before sunrise. They follow roughly the same path, moving from about the 9 o’clock to the 1 o’clock position on a clock face. At night they descend from around 11 to 3. I’m in Los Angeles, so they slide more slowly over the ocean compared to the equator.

For me, it’s kind of interesting that during the daytime we really don’t see what’s actually there because of the sunlight. When I’m riding my old motorcycle south of Interstate 5 in the early morning, the Milky Way, Magellanic Clouds, and stars a thousand times the size of our Sun are all out there on the horizon—even if I can’t see them with my eyes. It’s nice to check the app while riding and actually visualize what’s in the sky. Visualizng the Milky Way right in front of you on the horizon when riding is pretty special.

Here are some examples. https://imgur.com/a/7DNqemh

[Physics Guy]

I understand that M31, the spiral galaxy in Andromeda, is actually several times the diameter of the full moon, if you can resolve the faint light of its spiral arms. Its central core is bright enough to be seen with the naked eye on a dark night—well, noticed out of the corner of your eye as a bright smudge, that disappears when you look straight at it because you have too few rod cells in the center of your retina. The smudge shows up steadily in binoculars, but it doesn’t look nearly as big as the whole galaxy really is.

On scales from interplanetary to interstellar, space is not at all cozy. Planets are absurdly far from each other, compared to their sizes, like a pinpricks spread across a table. Stars are like periods printed miles apart; they just go on and on and on far beyond our ability to picture. Galaxies are so big that you just have to choose whether to think of the galaxy or the stars that compose it, because you can’t picture both. Either the stars are way too small to see, or the galaxy is way too big to fit in the frame.

On intergalactic scales, though, space is suddenly much more neighborly. Galaxies are only around ten or twenty galaxy-widths from each other. M31 is the nearest other full-size galaxy to the Milky Way, and if we could only see its faint light, it would be as familiar a sight as the Moon, only several times larger. Howdy, neighbor.

On the other hand, galaxies also just go on and on. The famous Hubble Ultra Deep Field shows a spread of galaxies that looks about as dense as a dark night sky is with stars. Almost every bright spot in the image is a whole galaxy, just extremely far away, not an individual star. The whole image is a portion of sky that can be covered by a grain of slightly coarse salt held up at arm’s length. Pretty much the whole sky is like that, every salt-sized pixel jam-packed with galaxies that are all so far away that it take a space telescope days to collect enough light to detect them.

That’s all awesome, all right, but I think it just discourages me from getting too much into astronomy. Whatever I might see is going to be such a small fraction of the whole that I just feel discouraged.