Largest Hubble Mosaics Ever Assembled

bobtheowl2 writes "The Hubble Heritage team of astronomers, who assemble many of the NASA Hubble Space Telescope's most stunning pictures, is celebrating its five-year anniversary with the release of the picturesque Sombrero galaxy. One of the largest Hubble mosaics ever assembled, this magnificent galaxy is nearly one-fifth the diameter of the full moon. The team used Hubble's Advanced Camera for Surveys to take six pictures of the galaxy and then stitched them together to create the final composite image. The photo reveals a swarm of stars in a pancake-shaped disk as well as a glowing central halo of stars."

Comments

Brave, brave people.

[daeley]

Very brave of them to make a 211 MB TIFF file available for download on this page. ;)

Aye, Cap'n!

[rudy_wayne]

At Warp 9 we'll be there in 38,000 years!

Re:It's a photoshop job.

[LMCBoy]

Peter,

I am not usually this relentless, but as an employee at STScI, your accusation of fraud really annoys me.

Anyway, I am prepared to prove you wrong. Please examine the animated GIF image I have placed at the following URL:
http://www.stsci.edu/~jharris/sombrero.gif

In the image, I have stacked the HST image and the VLT image on top of each other, and I am displaying each with the same scale and orientation. The first frame shows the HST image, the second frame shows the VLT image. You may need to set your browser to "loop" animated GIFs, or save it to disk and use a tool like gifview.

The rotation and scale are not perfectly matched, but it's good enough to see correspondence between the images.

Oh, wait. I think I see what you are on about. The "missing" stars are all in the dusty disk, right? If you look closely, they aren't gone in the HST image, just much fainter. The reason is simple: the intervening dust absorbs blue light much more than red light. These disappearing-objects are not foreground stars, they are probably star clusters in the galaxy.

If you read the technical data about each image:
ESO, HST, you'll see that the ESO image was taken through redder filters than the HST image (V,R,I compared to B,V,R), so it's no suprise that the ESO image is going to see through dust better!