Archives for September 2011
I don’t know about you, but when I see a link entitled “The Pacman Nebula“, I expect it to look like… Pacman. Y’know? After staring at the below image for a few moments, trying to see the Pacman, I looked up NGC 281 and found the above. (Which does, after a fashion, resemble Pacman.)
However, all confusion aside, the below image is quite lovely, and shows a sparkly side of Pacman that went hitherto unnoticed. (I’ve discovered that I posted another nebulous Pacman portrait about a month ago. APOD did not mention the resemblance, or the nickname. I’m surprised!)
High-mass stars are important because they are responsible for much of the energy pumped into our galaxy over its lifetime. Unfortunately, these stars are poorly understood because they are often found relatively far away and can be obscured by gas and dust. The star cluster NGC 281 is an exception to this rule. It is located about 6,500 light years from Earth and, remarkably, almost 1,000 light years above the plane of the galaxy, giving astronomers a nearly unfettered view of the star formation within it.
This composite image of NGC 281 contains X-ray data from Chandra, in purple, with infrared observations from Spitzer, in red, green, blue. The high-mass stars in NGC 281 drive many aspects of their galactic environment through powerful winds flowing from their surfaces and intense radiation that creates charged particles by stripping electrons off atoms. The eventual deaths of massive stars as supernovas will also seed the galaxy with material and energy.
NGC 281 is known informally as the “Pacman Nebula” because of its appearance in optical images. In optical images the “mouth” of the Pacman character appears dark because of obscuration by dust and gas, but in the infrared Spitzer image the dust in this region glows brightly.
NGC 281 is typically divided into two subregions: the region in the upper middle of the image, which is surrounded by the purple 10-million-degree gas, and a younger region in the lower part of the image. There is evidence that the formation of a cluster, appearing in a beige cloud to the lower right, was triggered by a previous generation of star formation. Also, astronomers have found some isolated star formation on the left side of the image that appears to have been occurring at the same time as star formation in other regions of the cluster. This supports the idea that something externally triggered the “baby boom” of stars in NGC 281.
Image Credits: X-ray: NASA/CXC/CfA/S.Wolk; IR: NASA/JPL/CfA/S.Wolk
A beautiful concept of the Space Shuttle from 1972, courtesy of x-ray delta one. It’s interesting to see how the external tank evolved — here it looks like a larger SRB, with a penthouse (or whatever other purpose that little top spike is supposed to serve.) The orbiter itself has a bit of a streamliner/Art Deco look to it.
Drifting through the cosmos a mere two and a half million light-years distant, the Andromeda Galaxy is the most voluminous of the galaxies in the Local Group, which includes our own Milky Way galaxy. Visible
to the unaided eye in a dark location, the central core can be seen as a tiny smudge. In a moderate telescope, M31 can be seen with its two largest satellite galaxies; M32 and M110.
Located in its namesake constellation, Andromeda contains roughly a trillion stars not including the 14 known satellite galaxies gravitationally bound to it.
Visible in this photograph are the dusty lanes of stellar debris visible as the dark bands. The remnants of stellar deaths, this material will be recycled into new stars and planets as gravitational forces compress the matter within the chaotic environment.
Also visible is the bright central core. Inhabiting the center of M31 is a super-massive black hole responsible for the increase in the density of stars, interstellar gasses, and dust. In this region, temperatures soar and cause the dust and gas to glow in visible wavelengths obscuring the innermost region.
M31 and our own Milky Way Galaxy are on a collision course. Expected to collide in roughly four and a half billion years, it should certainly provide a spectacular show for anyone around to witness its approach.
35 years ago, on September 17, NASA unveiled the space shuttle Enterprise to the delight of her TV crew. (Why Bones, you look so STYLIN’ in those gold bell-bottom slacks!)
In 1976, NASA’s space shuttle Enterprise rolled out of the Palmdale manufacturing facilities and was greeted by NASA officials and cast members from the ‘Star Trek’ television series. From left to right they are: NASA Administrator Dr. James D. Fletcher; DeForest Kelley, who portrayed Dr. “Bones” McCoy on the series; George Takei (Mr. Sulu); James Doohan (Chief Engineer Montgomery “Scotty” Scott); Nichelle Nichols (Lt. Uhura); Leonard Nimoy (Mr. Spock); series creator Gene Rodenberry; an unnamed NASA official; and, Walter Koenig (Ensign Pavel Chekov).
SPACE.com has a nice article about the Enterprise, a prototype and test vehicle that never felt the chill of space, but paved the way for the rest of the fleet!
The space shuttle prototype Enterprise flies free after being released from NASA’s 747 Shuttle Carrier Aircraft over Rogers Dry Lakebed during the second of five free flights carried out at the Dryden Flight Research Center, in Edwards, Calif., as part of the shuttle program’s Approach and Landing Tests (ALT). The tests were conducted to verify aerodynamics and handling characteristics in preparation for orbital flights with the Space Shuttle Columbia, which began in April 1981.