Purple Rose of Virgo?

Okay, I liked the Woody Allen film as much as anybody, but why has ESO titled its latest press release “the Purple Rose of Virgo”?

Aside from my lack of comprehension regarding the obscure (I’m not sure I could even call it “pop”) culture reference, I have a gripe with the reference to color. “Purple” is a tricky color, and one that doesn’t occur via blackbody radiation. So it seems inappropriate to describe a galaxy by a color it only possesses because of image manipulation.

In the biz, we call this “color enhanced.” But it should not suggest the actual color of the object, nor should it be used as the basis for a press release title!

Grumble. Time for more coffee.

(Oh, by the way, that’s a supernova below and to the right of the center of the galaxy! Nifty.)

Toppling the Pillars

Today’s press release from the Spitzer Space Telescope shows the Eagle Nebula in a new light. (You can also listen to a podcast about the result.) The Eagle was made famous by the 1995 “Pillars of Creation” Hubble image and perhaps also by the Hubble’s 15th Anniversary image release.

Spitzer is getting into the act now with the gorgeous images above, in addition to an image that came out with the aforementioned press release. The challenge for visualizing the data is that six different filters were used to look at the nebula—3.6-, 4.5-, 5.8-, 8.0-, 24-, and 70-micron filters, to be exact. Since most such pictures are created by assigning three filters to each of the red, green, and blue channels of a digital image, it gets tricky to condense an even greater amount of information into a single snapshot.

The side-by-side presentation of the data helps us piece together the story—namely that the longer-wavelength emission suggests a shockwave of material (most likely from a supervova) coming in from the upper right. It would be interesting to include a tool similar to one on the Hubble education site that would allow a user to turn on or off certain filters and combine them into a single image.

Alternatively, you could take the individual filters’ images from Spitzer and use a tool such as FITS Liberator to constrcut your own color image. (The European Hubble site offers a gallery of images created by users using said tool.)

However it happens, it would be fantastic to experience the images in a more flexible and interactive fashion.


The figure appears as part of an ESO press release about asymmetric supernovae. The closer I look at the figure, the more confused I get. I mean, the exploding star on the right indeed appears somewhat asymmetrical, but… What’s actually happening in this image?

The caption for the image reads, “Artist’s impression of how Type Ia supernovae may look like as revealed by the spectr-polarimetry observations. The outer regions of the blast cloud is asymmetric, with different materials found in ‘clumps’, while the inner regions are smooth.” Type Ia supernovae take place when gas from a companion star falls onto a white dwarf. The bright white star on the left looks suspiciously like a white dwarf, but it ain’t the one doing the exploding!

Then there’s the region of what appear to be brighter stars clumped around the “white dwarf.” Maybe that’s supposed to suggest infalling gas? But as previously noted, that’s not the star going boom.

So, yeah, I’m a little confused by this picture.