Starship Asterisk*

W5: Pillars of Star Formation

Explanation: How do stars form? A study of star forming region W5 by the sun-orbiting Spitzer Space Telescope provides clear clues by recording that massive stars near the center of empty cavities are older than stars near the edges. A likely reason for this is that the older stars in the center are actually triggering the formation of the younger edge stars. The triggered star formation occurs when hot outflowing gas compresses cooler gas into knots dense enough to gravitationally contract into stars. Spectacular pillars, left slowly evaporating from the hot outflowing gas, provide further visual clues. In the above scientifically-colored infrared image, red indicates heated dust, while white and green indicate particularly dense gas clouds. W5 is also known as IC 1848, and together with IC 1805 form a complex region of star formation popularly dubbed the Heart and Soul Nebulas. The above image highlights a part of W5 spanning about 2,000 light years that is rich in star forming pillars. W5 lies about 6,500 light years away toward the constellation of Cassiopeia.

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I think this picture is amazing. Unfortunately I am acutely sensitive to scaling. Is there confustion with the wording or is there something not correct in the description?
A Puzzle Of the Day if you will

Good catch. The original APOD caption says it is 6,500 light years away and 2,000 across. That would mean it would span a big chunk of the sky from Earth.

http://www.spitzer.caltech.edu/images/1 ... mily-Tree-

says that the distance is correct at 6,500 light years, and the angular size is about 2 degrees. That would mean it is about 200 light years in size - assuming that distance. So it looks like the size should be 200 light years instead of 2,000.

zloq

Indeed, that was a good catch. I wonder if there has been a mix-up between the size of the area portrayed in today's APOD and the large nebular complex that it belongs to. W5 is apparently a part of IC 1805, the Heart Nebula, but the Heart Nebula is in itself only a part of larger starforming region. See this image. It is annotated in Spanish (I think), but it should be relatively easy to understand the annotation even if you only speak English.

ON the other hand... a size of 2,000 light-years still sounds too much for a nebula which is just 6,000 light-years away and doesn't come close, even if you count every wisp of red in this complex, to cover a third of the sky.

Ann

You should have saved this one for Valentine's day.

I liked this simple YouTube demonstration that shows how star formation occurs!

Does anyone else see a hooted face in today’s picture? Looks like someone looking off to the right.

Wow! So much detail in this image! The colors really blend together well.

WOW, a gigantic CERN hadron collider