Added 2 new A* pages:Speaking of things drifting away, NASA posted an article this past Friday about star HE 0437-5439, classified as a "blue straggler": it's a massive, hot blue star 200,000 miles from the center of our galaxy, and high above the galactic plane. It's so far away that it's actually closer to some of our tiny neighboring galaxies, and scientists had initially thought it had come from one of them, but now by comparing its position in current and 3-year-old Hubble photographs, they've been able to determine that it's moving away from the center of our galaxy. (To give you an idea of the scant evidence astronomers are used to working with: even in Hubble's high-resolution images, the star had moved only 4% of a single pixel!)|
This raised some questions: namely, how did it acquire its unusually high rate of speed--1.6 million mph (2.5 million kph -- by way of reference, the speed of light is about 1 billion kph)--and how did a blue giant, which should only live for 20 million years, survive to what appears to be a 100 million year point in its voyage from the center of our galaxy?
image by NASA, ESA, and A. Feild (STScI)
NASA's current theory is that it is the remnant of what was originally a triple star system--a binary and a large primary--that moved too close to our galaxy's central supermassive black hole, Sagittarius A*: the large primary star in the system got sucked into A*, and the binary was flung away at very high speed. Then at some point in their voyage, the stars in the perturbed binary merged to form the blue giant we see today.
Which all just goes to show that even triple star systems shouldn't mess with A*. By the way, I don't think the depiction of A* and the area around it in that diagram above is really supposed to be to-scale/realistic; its event horizon is way smaller than that relative to the rest of the galaxy, and anyway it's surrounded by loads and loads of dust and gas that would prevent you from seeing the hole--not that you can really see black holes anyway. I do find it interesting that in this picture they made the stuff around it red; I wonder if that's meant to reflect the idea that as things fall into the event horizon, the light they give off gets stretched out, getting ever redder and fainter, until it fades out entirely as they cross the event horizon.
There's a new Princess and the Giant page up if you're interested in catching the latest from my weekly fairy tale comic. This one came out kind of weird--I seem to have been going through a Mannerist phase or something, ew--and also kept me up all night with the drawing of it, which has been the case more often than not lately; so I was stumbling around all sleep-deprived and sort of irritated with myself, when by some happy chance I found a Frank Frazetta picture book that I had bought some three years ago and immediately misplaced and forgot--it was still in its shrink wrap! So looking through that cheered me up; his work is so inspiring. And it reminded me that he spent his first nine years as a commercial artist working on comics! I'd love to see one of those collections of his Li'l Abner work from that period.