Category Archives: optics

Magnify the View and What do You Get?

Details!!

The Sombrero Galaxy, from the National Optical Astronomy Observatories web site.
The Sombrero Galaxy, from the National Optical Astronomy Observatories web site.

One of my favorite pastimes is web surfing for astronomy pictures. As a writer, it’s sort of an occupational hazard as well — since I have to populate my stories with great illustrations. Hubble Space Telescope regularly trolls some good ones out for all of us to see. This week the release was a great picture of the Sombrero Galaxy. It lurks in the constellation Virgo and lies about 28 million light-years away. That’s far enough away that until HST and some of our better ground-based observatories took at look at it, we had a hard time seeing details. For example, here’s The Sombrero (M104) taken in 1974 by the 4-meter Mayall Telescope at Kitt Peak National Observatory in Tucson, Arizona.

Sombrero as seen by ESO
Sombrero as seen by ESO

Okay, fast forward a few decades to the year 2000, and the European Southern Observatory’s ANTU installation. This observatory (part of a new wave of adaptive optics-equipped facilities) took this astonishingly beautiful picture.

Pretty darned snazzy, if I do so say so. Well, just this week, the HST released this puppy:

Sombrero from HST
Sombrero from HST

Now compare and contrast the ESO and HST image. One of the arguments for HST being above the atmosphere was that it would free astronomers from the tyranny of Earth’s meddling blanket of air. And it has. But, the ground-based facilities haven’t been content to sit still and let Hubble grab all the good stuff. Advances in adaptive optics are to the point where ground-based observatories are pushing the close behind and in some cases equalling HST’s performance. And this is great because it means that we have more capability for high-resolution, detailed views of the universe. And, Hubble is still up there, giving us a peek at the infrared and ultraviolet universe that is so difficult (if not impossible) for ground-based instruments to observe. (It’s that pesky atmosphere and in the UV case and some “flavors” of case, it can’t be overcome without leaving the ground.)
So, three pictures of the Sombrero pretty well illustrate the advances we’ve made in optical astronomy over the years. It’s a grand time to be an astronomer!